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PPC USER MANUAL

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2. B Voltage 4 20mA R A OPTION 1 AIN1 1 select each channel jumper selectable AUTO CAL lt AIN2 EEPROM gt 2 2 3 y aa cae 16 BIT BIPOLAR 5 5 MUX ANALOG DIGITAL gt HD 6 AIN6 6 CONVERTER AIN7 100mV 1V T ETA 7 select 1 8 8 le le 9 E TEMP SENSOR 14 21 ANALOG GROUND D2 OPTION gt AOUT1 16 BIT BIPOLAR la 9 AMP DIGITAL ANALOG 4 a _ 10 CONVERTER aA AOUT2 16 BIT BIPOLAR 10 AMP DIGITAL ANALOG 4 2i CONVERTER 25 DOUT1 13 DOUT2 PEN 11 DIN1 R Ll 12 DIN2 gt 2 4V 4 20mA transducer supply AP OPTION X23 4 10V bridge transducer etc supply FLOATING E 24 lt AUXILIARY 4 a i OV POWER SUPPLY gt 22 4 a i jumper selectable to ground Facilities and Operating Modes The PPC Analog Subsystem can be accessed from Basic Pascal and C programs For measurements the PPC Analog Subsystem supports both voltage and 4 20mA current loop inputs Voltage inputs are software switchable to 100mV or 1V In the current loop mode the transducers The selection between voltage and current loop mode is basis In voltage mode all readings are returned as 16 bit signed integers a operated upon using PPC s fast 32 bit floating point maths facilities For current loop mode the AP option is required This provides a 24V PPC can read and po
3. C 2 2 Get Started To terminate the program press CTRL C You may have to press it more than once Step 7 Autoexec operation This is the final step in producing a standalone protocol converter In the Config amp Diagnostics function select the Runtime Port Configuration This displays the runtime configurations for all the ports These configurations apply only when a Basic Pascal or binary compiled C program is running Furthermore the Port 1 configuration applies only to programs running in autoexec mode as ours will be in a moment Ensure that Port 1 is set to 9600 baud 8 bits word no parity and 1 stop bit All six handshakes should be in their factory settings all ON except XON XOFFs Return to the main Executive menu with two ESC keys Ensure the gt directory marker is displayed next to your BTOCP program Select the Define Power Up Action function highlight the Run Selected Program item and press J Your program is now autoexec Return to the main Executive menu with ESC Next time the PPC powers up it will automatically compile and run your program To test it select the Reboot the PPC function After a few seconds the READY prompt will appear and the program runs as before Note that the program cannot now be terminated with CTRL C or with any other key To return to the Executive press all three switches SW1 SW2 SW3 on the front panel and when the RST LED illuminates release SW2 SW3 only Maint
4. 1 Interactive Basic Pressing when this item is highlighted enters the PPC BASIC interpreter You can simply type in a program and RUN it For a list of commands and functions type HELP For full details see the PPC BASIC chapter 2 Create program Pressing when this item is highlighted enters the PPC function which is normally used to create all PPC programs PPC74 Create Program A1_PAOG Pasca 764 ADCTEST Basic 245 CALCOMP Pascal 11071 CUTDATA Pasca 131 negprag DACTEST Pascal 357 EDITDEMO Basic 1457 TEPROM Pasta 302 PLOT_DRU Basie 14024 SET PORT Vasra 211 Enter new name here TOUPPER Pasral 100 TSTCLOCR Pasta 182 Bytes 23081 space Jb6h Enter the new programs name Max 8 chars anly AZ OF oe 7 Program directory Backspace control Y clears line for reference only Contrul R repeats last name When you have entered the program name you will be prompted for the language Basic or Pascal The actual create operation can take up to 10 seconds and following this the newly created program will appear in the directory with a filesize of zero bytes You can now use the PPC Editor to enter text into the program You will remain in the Create Program menu for convenience in case you wish to create more programs To return to the main menu press ESC The PPC has no facility for changing the language attribute of a program once it has been created The only way to change it is to trans
5. When the ADCC or DACC functions are invoked the PPC performs an automatic zero and scale calibration on the 16 bit integer value involved The calibration values are stored in a dedicated EEPROM located on the analog card The EEPROM can hold up to 64 16 bit integer values of which only the first 21 are currently used as shown below Address Nominal value Function 0 1 0 16384 zero amp scale cal for all 8 ADC inputs 1V 2 3 0 16384 zero amp scale cal for all 8 ADC inputs 100mV 4 11 16384 scale cal for current loop mode on inputs 1 8 12 19 0 16384 zero amp scale cal pairs for DAC outputs 1 4 20 16384 scale cal for 10V auxiliary output uninitialised 21 63 not used at present The functions ANEERD and ANEEWR can be used to read and write respectively individual integer locations in the EEPROM Function ANEEWR returns an errorcode which if non zero indicates either an invalid address or a EEPROM write error If you modify any of the calibration values the new value will not become active until the ADCINI function has been called or until power down If you must use ANEEWR test your program first on one of the unused locations 21 63 In common with all EEPROMs the EEPROM has a limit of 10 000 writes per location DIN1 read TTL input 1 DIN2 read TTL input 2 FUNCTION DIN1 BOOLEAN FUNCTION DIN2 BOOLEAN The Boolean value returned by this function is the current unlatched state of the TTL level in
6. confusion with many application programs some of which require the and others must not have it KTERM is more intelligent and accepts both formats Do not try to change the KTERMFILES environment variable when you have shelled out of KTERM with control z MS DOS will discard your changes when you un shell back into KTERM This is normal MS DOS behaviour File transfer security All file transfers are CRC checked A corrupted file will be refused by its destination KTERM or the PPC and you will have to re initiate the transfer If errors persist choose a lower baud rate 7 2 KTERM aj aj DOS shell KTERM has a very useful feature known as shelling out Type alt z type z while holding down the ALT key KTERM now opens up another copy of COMMAND COM the MS DOS command line processor and you can run normal MS DOS commands and programs While shelled out KTERM remains resident which reduces your PC s conventional memory by approximately 80k bytes and it can still receive data sent by the PPC To un shell back into KTERM type EXIT at the MS DOS command prompt KTERM will restore its original screen content which may also have been updated with any data received from the PPC while shelled out While shelled out do not load any resident programs TSRs When you un shell back into KTERM the PC will probably crash This is normal MS DOS behaviour While shelled out do not run any programs which might a
7. string is an array of characters defined as S ARRAY 1 N OF CHAR where N is an integer between 1 and 255 inclusive Strings defined as above can be initialised or manipulated with standard constructs such as WRITE port1 S S hello IF S hello THEN Literal strings should not contain end of line characters CR 13 if they do then an error message is generated Strings may not contain more than 255 characters The characters available are the full expanded set of ASCII values with 256 elements To maintain compatibility with Standard PASCAL the null character is not represented as i e two single quotes with nothing in between instead 0 should be used PPC PASCAL 6 5 The construct gives the corresponding ASCII character There may not be spaces or commas between multiple components of a character string the two lines below are not equivalent write port1 7 hello is invalid write portl 7 hello outputs a BELL a beep followed by hello In the second example line above the character 7 forms a part of the quoted string and an equivalent statement would be write portl 7 hello SIMPLE TYPE type identifier On O He constant Scalar enumerated types identifier identifier may not have more than 256 elements TYPE The reserved word PACKED is accepted but ignored since packing already takes place for arrays of characters etc The only case in which the packing
8. will establish a PC modem connection at e g 38400 baud 3 Your modem does not support 9600 baud at all and a lower baud rate 2400 or 4800 must be used The commands setser coml 2400 n 8 1 kterm r ni will establish a PC modem connection at e g 2400 baud 4 Your modem supports 1200 baud or less e it is a V21 or V2123 modem Since the lowest settable Executive Mode baud rate is 2400 baud you cannot perform any Executive functions over a modem connection Sorry The r option instructs KTERM to use the standard RTS CTS modem handshake lt also slightly modifies the PC PPC file transfer timings to handle short gaps in data flow caused by the handshaking with buffered MNP modems Operation When KTERM is invoked as shown above you will initially see a blank screen Typing AT lt CR gt must return the standard OK modem response This also sets the modem s port to the PC s baud rate Enter the standard Hayes dial command e g ATDT 0712345678 lt CR gt and the modem dials the remote PPC s modem When a connection is established between the modems the standard response CONNECT 2400 or similar appears At this point press one or more of the following keys until the Executive menu appears a key or key sequence which terminates your autoexec program ESC control q Note that control c will not usually terminate an autoexec program Even if you have not disabled break checks with C the PPC automati
9. CTS and DSR inputs For example some plotters will ignore incoming data or e g in case of HP pen plotters will not respond to interrogation commands unless those inputs are HIGH The PPC port should be configured with the following handshakes RX handshakes RTS DTR XON XOFF TX handshakes CTS DSR XON XOFF OFF OFF OFF ON ON ON or as required by the device being driven 8 10 PPC Serial Ports PPC CalComp plotter cable DTE Host CalComp pen plotters except the A3 A4 models Colorviewt and Plotmastert are unusual in that they use DCE straight through connections The following cable is suitable for driving most of the old CalComp pen plotters and Supports both hardware and XON XOFF handshakes PPC 9 way 5 GND 3 TX 2 RX 8 CTS GROUND SHIELD DATA XON XOFF HARDWARE HANDSHAKE The PPC port should be configured with the following handshakes RX handshakes RTS DTR XON XOFF OFF OFF OFF or as required by the device being driven TX handshakes CALCOMP PLOTTER 25 way GND 1 7 RX 2 TY 3 RTS 5 CTS DSR XON XOFF ON Where more than one connector is provided on the plotter use the one marked DTE HOST If using the connector marked DCE HOST or for the devices marked whose single connector is effectively DCE HOST use the more common PPC printer plotter cable on the previous page PPC Serial Ports 8 11 1 0 Expansion Options
10. FUNCTION COS X real or integer REAL Returns the cosine of X where X is in radians The result is of type real TAN FUNCTION TAN X real or integer REAL Returns the tangent of X where X is in radians The result is always of type real ARCTAN FUNCTION ARCTAN X REAL REAL Returns the angle in radians whose tangent is equal to the number X The result is of type real EXP FUNCTION EXP X real or integer REAL Returns the value e X where e 2 71828 The result is always of type real PPC PASCAL 6 21 LN FUNCTION LN X real or integer REAL Returns the natural logarithm i e to the base e of X The result is of type real If X then a Maths Call Error will be generated This error can be disabled with the O compiler option HALT PROCEDURE HALT The procedure causes program execution to stop with the message Halt at PC XXXX where XXXX is the hexadecimal memory address of the location where the HALT was issued Together with a compilation listing HALT may be used to determine which of two or more paths through a program are taken This will normally be used during debugging RANSEED PROCEDURE RANSEED X Y Z INTEGER This procedure has three integer parameters which are used as seeds for the random numbers produced by RANDOM These integers must be between 1 and 30000 Normally the same random numbers are generated by RANDOM for each run of a program this procedure can be used to give different numbers RAN
11. transfer aborted Press any key These messages indicate that the version of your copy of KTERM EXE does not support a new feature of the PPC Obtain the latest copy of KTERM EXE from your PPC supplier Overwrite file Y N A file of the same name as the file being transferred already exists on your PC Error writing Error overwriting The file you are transferring to the PC cannot be written the possible reasons include 1 A file of the same name already exists and is marked read only 2 A directory of the same name already exists 3 Your disk is full 4 Your disk is write protected Directory does not contain any KTERM files Transfer aborted Unable to open file Transmission aborted 1 You have requested a PC gt PPC file transfer but KTERM cannot find any BAS or PAS files 2 The files to be transferred to the PPC must reside either in the current directory or in the path given by the environment variable KTERMFILES path File is empty Transmission aborted The filesize is zero Zero length files cannot be transferred File is too large Transmission aborted Maximum file size supported by KTERM is 32k bytes In addition a lower limit may apply when transferring PC gt PPC and there are already some files in the PPC s filespace 7 10 KTERM PPC Serial Ports Cables This chapter covers the details of the four serial ports Each of the four ports is normally RS232 but can be configured for RS422 or RS
12. Executive 1 If the EXE LED is not flashing then the PPC is configured to execute autoexec a program at power up To force entry into the Executive mode press SW1 SW2 SW3 until the RST LED comes on then release SW2 SW3 only holding down SW1 until the EXE LED starts flashing If the EXE LED is flashing then the PPC is already in the Executive and it most likely is a communications problem in the connection to the terminal Try the following e Reset the PPC by holding SW2 SW3 together until the RST LED comes on wait for EXE to start flashing again and try again e f using a non KTERM terminal press ESC on the terminal several times f using a non KTERM terminal check it is configured for XON XOFF only not hardware handshake and s set to 9600 N 8 1 e f using KTERM press ESC several times If using KTERM exit it with ALT X and re enter e f using KTERM try a different serial port on the PC e g COM2 e Someone may have changed the Executive mode baud rate from its 9600 baud default lt can be 1200 38400 If using a non KTERM terminal try setting it to other likely baud rates If using KTERM try setting the PC to different baud rates with e g SETSER COM1 38400 N 8 1 and then running KTERM with the NI override KTERM NI The PPC hangs on entry to Runtime Port Configuration menu You are not using the correct cable See the Cables section in the PPC Serial Ports chapter for details A progr
13. If your program is correct and if the input data is correct then errors should not occur but spurious characters can appear after power up and unnecessarily lead to fatal errors It is prudent programming practice to read data one byte at a time into a buffer and at a suitable point process the buffer e g with the VAL procedure this avoids the above errors in a proper manner Option 0 This controls whether general runtime errors are fatal If O the default is selected then checks are made for errors in the various integer and real arithmetic operations including log and trig functions and for overflow when reading numeric values with READ or READLN O disables these checks and results in higher execution speed and Suppresses the following error messages Number too large Overflow DIV by zero The 0 option is intended for finished and debugged programs which execute in the autoexec mode and therefore may have no means of reporting runtime errors Ignored runtime errors will result in undefined variables or worse A program in which an error occurs is almost certainly not going to do what it was written to do Disabling runtime errors is not a substitute for writing and debugging your program properly Option C Controls whether or not keyboard checks are made during object code program execution If C the default is selected then a CTRL C character 3 received on Port 1 breaks program execution reports the address where
14. Larger whole numbers are treated as reals The mantissa of reals is 23 bits in length The accuracy attained using reals is therefore about 7 significant figures Note that accuracy is lost if the result of a calculation is much less than the absolute values of its arguments e g 2 00002 2 does not yield 0 00002 This is due to the inaccuracy involved in representing decimal fractions as binary fractions It does not occur when integers of moderate size are represented as reals e g 200002 200000 2 exactly The largest real available is 3 4E38 while the smallest is 5 9E 39 There is no point in using more than 7 digits in the mantissa when specifying reals since extra digits are ignored except for their place value When accuracy is important avoid leading zeroes since these count as one of the digits Thus 0 000123456 is represented less accurately than 1 23456E 4 Hexadecimal numbers are preceeded by the character Note that there must be at least one hexadecimal digit present after the otherwise an error message will be generated 6 4 PPC PASCAL UNSIGNED CONSTANT constant identifier character string CONSTANT constant identifier character string Constants may be specified with the character which may be optionally followed by a to denote a hexadecimal number The two example lines below are equivalent CONST bs 8 cr 13 CONST bs 8 cr 0d CHARACTER STRINGS 3 characters A
15. The control variable of a FOR statement may only be an unstructured variable not a parameter This is half way between the Jensen Wirth and ISO standard definitions Note that due to the signed integer implementation in PPC PASCAL the absolute difference between the start and the end value in a FOR loop may not be greater than 32767 Examples FOR I 16384 TO 16384 DO invalid FOR I 16384 TO 16383 DO valid GOTO statements It is only possible to GOTO a label which is present in the same block as the GOTO statement and at the same level You may not use GOTO to jump out of a FOR statement Labels must be declared using the Reserved Word LABEL in the block in which they are used a label consists of at least one and up to four digits When a label is used to mark a statement it must appear at the beginning of the statement and be followed by a colon WITH statements WITH statements may not be used recursively use the full specification of a field identifier when using it as a parameter to a procedure which is called recursively PPC PASCAL 6 13 BLOCK unsigned integer j identifier 7 7 C 3 he o pee FORWARD PROCEDURE identifier parameter list identifier parameter list type identifier Forward References As in the Pascal User Manual and Report Section 11 C 1 procedures and functions may be referenced before they declared through use of the Reserved Word FORWARD e g PROCEDURE a y t FOR
16. The following diagram shows the arrangement for each PPC 4 port The PPC E uses identical components refer to the table further below for which components apply to which port IC A IC B IC C LJ LI LJ J A The following table shows which compon Component positions shown for PPC 4 board PPC E uses identical components see tables below for identification ents are used for each port function IC A IC B Ic C RN A RS232 14088 or 750188 14089 or 750189 4x4k7 RS422 485 LTC491 The following tables show which components apply to which of the four ports PPC 4 J A IC A IC B Ic C RN A Port 1 J1 IC1 102 103 RN1 Port 2 J2 104 105 IC6 RN2 Port 3 J3 IC7 IC8 IC9 RN3 Port 4 J4 IC10 1011 1012 RN4 PPC E J A IC A IC B IC C RN A Port 1 Ji IC9 IC10 1027 RNI Port 2 Ji IC11 IC12 IC28 RN2 Port 3 Jt IC13 IC14 1029 RN3 Port 4 J1 IC15 1C16 1030 RN4 The LTC491 has various equivalents e g MAX491 or MAX489 where lower slew rate better for EMC is required The RN network is an 8 pin inline resistor network containing four separate 4k7 5 resistors The polarity of the network in its socket is not important PPC Serial Ports 8 3 aj aj aj Fit a 14 way pin header into the now vacant IC B 14C89 or 75C189 socket This header must be wired to interconnect pi
17. V There are 4 cases to consider 1 V is of type char In this case READ P V reads a single character from the specified port and is assigned to V If having read this character another character is waiting in the input buffer and this waiting character is a line marker 13 then the function EOLN P will return the value TRUE If the character is a line feed LF 10 then it is removed from the buffer and discarded and the next character is read If you need to process LF characters use the BREAD procedure instead 6 18 PPC PASCAL aj aj 2 V is of type string array of char A string of characters may be read using READ and in this case a Series of characters will be read from the specified port until the number of characters defined by the string has been read or EOLN becomes TRUE If the string is not filled by the read i e if end of line is reached before the whole string has been assigned then the end of the string is filled with null 0 characters this enables you to scan the array and evaluate the length of the string that was read The READ procedure will wait until either the array has been filled or EOLN becomes TRUE This can cause your program to apparently hang if insufficient input data arrives Use this method only if you are sure that the input stream will contain CRs or CRLFs at regular intervals or if waiting for input does not matter 3 V is of type integer In this case a series of characters wh
18. a null 00h character This character always appears in the receive queue as a result of a break condition on the input port However the behaviour of ports 1 2 differs significantly from ports 3 4 On ports 3 4 the reception of a break character returns a single null 00h character in the receive queue This is regardless of how long the break condition persists On ports 1 2 the reception of a break character returns multiple nulls the number of nulls is equivalent to the number of ordinary characters that would be received at the current baud rate during the duration of the break condition For example if the port is set to 9600 baud and the break persists for 270ms then approximately 270 nulls are received This would cause the input queue to overflow and cause the PPC to return an input busy handshake condition In applications where break characters are expected on port 1 2 this situation can be easily handled in software as the following Port 2 example code shows var c char brkrecd boolean brkrecd false assume break not received bread port2 c wait for a char on port 2 if c 0 then begin if null received loadtimer 0 300 then wait for 300ms while readtimer 0 lt gt 0 do ipqclear port2 and clear the input queue brkrecd true and mark break received end The above code assumes that the input break condition will last for less than 300ms PPC PASCAL 6 37 Analog Subs
19. and TRUE is represented by 1 we can achieve the above with BASIC 5 5 IF A 22 B 43 2 PRINT both true which takes advantage of the fact that A 22 will produce a result of 1 if TRUE and B 43 will also produce a result of 1 if TRUE If they are both TRUE their sum will be 2 GOTO This command transfers execution to the line number following the GOTO command Note that the GOTO command must be the last command on a line it cannot be followed by a semicolon and other commands GOSUB RETURN GOSUB js like a GOTO but produces a subroutine call to a subroutine at the specified line This subroutine must return with a RETURN command otherwise a STACK OVERFLOW fatal error will eventually result GOSUB 100 standard usage GOSUB 100 X 10 line number computed at runtime The last example above allows one of several subroutines to be called depending on the value of X being 0 1 2 etc and assumes the corresponding subroutines start at line numbers 100 110 120 etc A fatal MISSING SUBROUTINE error will result if X somehow acquires a value which is out of range so use this feature with great care Subroutine calls can be nested to a depth limited only by stack space currently around 50 levels FOR NEXT These commands are used to execute a part of a program a specified number of times 10 FOR X 0 TO 100 STEP 5 20 PRINT X X X 5 X 5 30 Y Y X 40 NEXT X In the above example lines 20 and 30 will be executed with
20. at this pin Also when XON XOFF is enabled as a TX handshake any XON XOFF characters arriving at this pin will be stripped by the PPC and will control the data flow from the TX output Request To Send output When enabled as an RX handshake this signal is automatically controlled by the PPC and controls the data flow into the RX input When not enabled as an RX handshake this signal can be freely controlled from PASCAL or C The name of this signal dates back many years and no longer means very much except when used with modems Clear To Send input When enabled as a TX handshake this signal is automatically monitored by the PPC and controls the data flow from the TX output This signal can also be freely monitored from PASCAL or C If no connection is made to this pin it will be internally pulled up to a READY RS 232 high level state The name of this signal dates back many years and no longer means very much except when used with modems Data Terminal Ready output When enabled as an RX handshake this signal is automatically controlled by the PPC and controls the data flow into the RX input When not enabled as an RX handshake this signal can be freely controlled from PASCAL or C The name of this signal dates back many years and no longer means much except when used with modems PPC Serial Ports 8 1 DSR Data Set Ready input When enabled as a TX handshake this signal is automatically monitored
21. be multiple peripherals Slaves All the Slaves have their connections parallelled To convert the above 4 wire port to a 2 wire port interconnect TXA RXA pins 2 3 and TXB RXB pins 6 7 RS422 RS485 grounding All RS422 485 receivers have a finite common mode voltage range typically 7V to 12V If you can guarantee that in your system this will never be exceeded then the GND connection is not required In practice this may be hard to guarantee and the GND connection should always be present except where there is a serious risk of a ground loop with resulting heavy ground currents 8 2 PPC Serial Ports RS422 RS485 Termination If your cable length exceeds several hundred metres then a termination resistor equal to the characteristic impedance of the cable should be connected between the two wires representing each signal A terminator is required at each end of the cable four terminators are therefore required on a RS422 or 4 wire RS485 system and two on 2 wire RS485 In practice terminators are much over rated and are usually not required They also waste a lot of DC power this can be avoided by connecting a series capacitor e g 1000pF with the terminator RS232 to RS422 RS485 port conversion With power OFF remove the four rear panel screws and withdraw the rear panel complete with the attached PCB You will notice that next to each of the four 9 way D connectors there are three IC sockets and an 8 pin resistor network
22. binary read procedure is one of the PPC extensions and allows the input of arbitrary binary data It supports the input of variables only V1 Vn It is the opposite of BWRITE and any variable written with BWRITE can be read with BREAD and the result is the same as the original variable The port must always be specified if it is missing the error message which appears may not be obvious The following examples show the data expected for each type of variable char 1 byte integer 2 bytes less significant byte arrives first real 4 bytes array 1 76 of char 76 bytes a 55 2 bytes if a is an integer array When BREAD is used to read characters it is capable of receiving the entire 256 character set from 0 to 255 inclusive Control characters e g CR LF are not treated differently Also allowed is the form bread port v i which reads in i bytes into the variable v which would usually be an array When XON XOFF is enabled as a TX handshake on this port any XON XOFF characters arriving at this input port will be removed from the data stream by the PPC comms processor Your PASCAL program will not see them Unlike READ amp READLN BREAD performs no break CTRL C checking If your program is waiting for input there is no means of terminating it except by resetting the PPC PPC PASCAL 6 19 File Handling Functions EOLN FUNCTION EOLN PORT TEXT BOOLEAN The function EOLN is a Boolean function which returns the v
23. but must be the ast command on a line BASIC 5 7 Direct Commands The commands below can be executed only in direct mode i e by themselves and not as part of a program They must not be preceeded by a line number Direct commands may be entered in uppercase or lowercase but the entire command must be in the same case Direct commands are applicable only in the PPC Interactive Basic mode HELP This command lists all currently implemented BASIC commands and functions RUN This command starts the execution of the current program in memory starting at the first line LIST This command prints out the current program Partial listings are possible LIST 200 prints out the current program from line 200 onwards NEW This command deletes the current program from memory allowing a new program to be typed in It does not delete anything from the PPC filing system SAVE This command stores the program currently in memory in the PPC s filing system For example the command SAVE PROG1 stores the program as PROG1 with a language attribute of BASIC The program can then be edited with the PPC editor downloaded to a PC etc See the PPC Executive chapter for more information LOAD This is the opposite of SAVE The command LOAD PROG1 loads the BASIC program PROG1 into memory ready for a RUN command etc DIR This command lists the current PPC filing system directory for reference KILL This command deletes a file fr
24. c file s into a single bin file which is transferred to the PPC using the file transfer functions of the supplied KTERM EXE terminal emulator Once this bin file is designated autoexec it runs when the PPC is rebooted Also with PPC v1 07 you can run it from the Compile and Run menu item That is all there is to it The C option consists of the following 1 An enlarged PPC ROM which contains the C runtime library routines Because almost the entire runtime library is in ROM as is also the case with PPC Pascal the entire 30 464 byte RAM area is available for compiled code This enables the generation of large programs Because C programs are cross compiled on a PC and also due to greater code efficiency of C versus Pascal C programs can be typically 5 times larger in of lines than can be achieved with PPC Pascal This makes C recommended for highly complex PPC applications 2 A Hi Tech 7180 64180 C cross compiler version 7 31 or higher This compiler is available in MS DOS and other versions It is priced separately from the PPC and must be ordered separately This compiler is a standard off the shelf unmodified Hi Tech product 3 A diskette containing a PPC specific runtime library symbol table in OBJ format Your C program is linked with this symbol table and this ensures that it calls the various ROM based library functions at the correct addresses Also supplied is a C example program a makefile and other utilities require
25. eee ee Da OY hee Ra ee he 6 57 NEO e a e Ant IATA co LL e e A SU a MA 6 57 Characters Booleans and other Scalars ooo 6 57 AA A A SAR eek eS 6 57 BODAS isd ia A td a 4 ayaa aa A 6 57 A O Boeke Ue tel Aa amp 6 57 RECORDS ANG ANAS as Pico at add Sun Saket daa 6 57 OOS Ald Dog hrs dea eek ea Dior a dba ts 6 58 A ol IN ak Wyse ebb atlas ta at eb te ace Mea wh oh aa 6 58 Recommended BOOKS r Sasani ater wiper at deck anand Goa re ate Sangh Geta dd gt ce Uk 6 59 A coven 02 O MK ies tS A aA 6 59 Reference BOOKS cnar way St Che scence p O Beare II A Ge A Ngee fy a A ke ad 6 59 KTERM Terminal EMulalOf tv tr oxy eA Adee aad done ie On he de ba da 7 1 WS HERR Os fit ob ce are dean gh a hath athe hey led Sone Te dia den a 7 1 WIPUSSIKTERNMZ ad ais UA o a iD delet di 7 1 TERM ANST ATG IN a nds Md komen ah dh tii 7 1 KTERMFIGTANSION Loti araa trado atada dada dos 7 1 1 To transfer a file from the PPC to your PO o o 7 2 2 To transfer a file from your PC to the PPC o 7 2 PPC PC filename relationships ooo oo 7 2 PG filename directory control gov keke ie di a Beda iaa 7 2 Ele transfer security a coats Se E dai nd 7 2 NUS Sil say tie aa ideas ae A n Wow its NE Mat ech eta cee tdi bra 7 3 KTERM command line options 20 00 se A 7 3 KTFERM GXaM DIOS as er ii ayes 2a ee ile Besa Rove a Ge Ae aaa eee aR He cha oe a 7 4 KTERM under Windows 3
26. in RAM Code and data share a single 30 464 byte RAM area from 0x8800 to OXFFOO The following diagram illustrates the memory allocation OXFFFF OXFFOO RUNTIME LIBRARY WORKSPACE RUNTIME STACK FREE RAM RAM HEAP STATIC VARIABLES BSS CONSTANT DATA amp STRINGS C COMPILED CODE 0x8800 PPC WORKSPACE 0x8000 C RUNTIME LIBRARY ROM 0x2000 PPC COMMS ETC 0x0000 The shaded areas are shown for information only You do not need to know anything about them The bin disk file which you create contains code any const strings and any const data Upon PPC reboot it is loaded by the PPC firmware at 0x8800 As you may note from the linker invocation in the supplied makefile at the code entry point at 0x8800 is a small piece of code jp2main This performs two important functions 1 It checks that the version of your compiler is compatible with the version which was used to produce the ROM based runtime library a mis match which is a fatal error is indicated by a permanent moving 00000001 pattern on the PPC LED display 2 It jumps to the main function in your program which may be anywhere in the program Because the entire program is in RAM any const data or strings are modifiable To ensure that your compiled program calls the ROM based library functions at the correct ROM addresses you link your program to a supplied OBJ module which is basically just a compiled symbol table which c
27. invoke it 3 Exit KTERM reset the PPC by holding SW2 SW3 together until the RST LED illuminates wait for the EXE LED to start flashing then re invoke KTERM If the EXE LED does not start flashing the PPC is probably configured to automatically run a program and you must use the Executive Mode force entry procedure press all three switches until RST illuminates and then while still holding SW1 release SW2 SW3 The PPC will now enter Executive Mode 4 Check you are using the correct PC port COM1 or COM2 5 Check you are connected to the correct PPC connector marked PORT1 PORTS 6 Check you have the correct cable see Serial Ports and Cables chapter between the PC and the PPC If you have made your own cable it must have at least those connections shown on the PPC bottom label Garbled data appears 1 Exit KTERM with alt x and re invoke it If the problem is due to mismatched baud rates this will equalize them 2 If only a few characters are corrupted your baud rate is probably too high Select 19200 or if the problem persists 9600 baud Editor display is incorrect or other display faults Exit KTERM with alt x and re invoke it For an explanation see the invalid cursor position error message further below Control c does not stop program execution 1 There is already some data in the Port 1 receive queue This will prevent the ctrl c being seen 2 In a PASCAL program you have disabled break checking with the C
28. letrada 4 1 PNG WOGES i ete sect tng g aaa e lah ls a a Da ra dde i 4 1 Editor Commands irass esene a is te as re ds 4 4 2 GursoreMoving Commands ratin eaa sd Se Be ven Sow eR Be Aa a 4 2 Text Deleting Commands a 4 3 A A ON Maren 4 3 Quick G rs r Movements sd atia ir a Ges e A te 4 4 PID an SUD SUMING Ae e des a AS RA a Dee chad he eee 4 4 LSVINO METEO na Sey ole a Miko ak epee amp 4 5 A th Noo CRO AM TR AN 4 5 Miscellaneous Ssss coro road aha SG hee taco Reese 4 4 6 Promptsand Messages souks ape hae gene hw bea dy Fal ab ga Schaal A ee de de tes 4 7 PROMS ic 2 ol ana O Fon alee BS eS oe AED toe ap BTS aoe Oe eet a 4 7 Editor EOF MESSAGES Y os in Bawa Ge eee AS Bay A eee Sale de E tue bean oe ESA 4 7 CMO IIMS A o ls Cd cnet ds Mak he E fa eM eg 4 8 AA A haath Bh late aie Boy eed 4 8 PPCBASIGE 4 fg 6 th ahs wide Beeman eta ao puede Leah e ira 5 1 Wigs PPG BASIC a drs oo i teat we ck wake we eer eee Ae Wa A pa 5 1 Performance de mu oft aa Be a ctl Pinta ed Be hte Mord on edt e Date oP ew dab ot Seale ae a 5 1 PXAMPIG2 22 oct Cth nl Ae ops a a neds do e Moda ws o De Aa e a tht Ay ot 5 1 How to create a PPC BASIC program aa aa a 5 1 How to execute run a PPC BASIC program si DAS A 5 1 PPC BASIC language description ce a ir a BG wis 5 1 NUDE o O N TENER Y 5 2 Varia D ES ausent a rd Sat datos Y At A ON DS 5 2 FUNCIONS a 624 aor Angi a ea it heed RU a A e a hud 5 2 Arithmetic and Compare Operators gt oa
29. of X and a CRLF PRINT TOTAL X as above but no CRLF is output at the end allowing another PRINT statement to continue output on the same line Both single and double quotes may be used provided they are matched The numeric values which are output can be positioned on specified boundaries using the operator PRINT 2 X 4 Y outputs the values of X and Y with X right justified in a 2 character cell and Y right justified in a 4 character cell if the values are too long to fit into the cells they are output anyway Default cell size is 6 chars The PRINT command supports expressions PRINT TOTAL1 X 45 TOTAL2 Y 2 X Two special operators HX2 and HX4 are provided for outputting numeric values in hexadecimal PRINT HX2 X HX4 Y outputs the values B3 and 43AF if X 179 and Y 17327 decimal Note that 17327 decimal outputs as BC51 The CHR operator outputs a single character corresponding to the ASCII value of the variable PRINT CHR X outputs the character M if X 77 decimal IF This conditional tests the value of an expression and if the value of the expression is TRUE i e non zero executes the commands to the right of the expression Two simple examples are IF A 22 X 30 IF A 22 X 30 GOTO 30 Note that the word THEN used by other BASICs is not used Multiple logical expressions such as IF A 22 AND B 43 PRINT both true are not supported However noting that in PPC BASIC the value FALSE is represented by 0
30. of an MS DOS filename However the PPC files do have a language attribute which is displayed in the Executive directory This attribute determines the filetype which the MS DOS version of the file will acquire upon transfer PPC language attribute MS DOS filetype BASIC BAS PASCAL PAS BINARY BIN and the above relationship applies in both directions PC filename directory control As default all files transferred from the PPC to the PC are stored in the current directory However this can be changed with the KTERMFILES environment variable For example an environment variable KTERMFILES C KTERM TRANSFER or KTERMFILES C KTERM TRANSFER will ona PPC PC transfer write the files into the directory specified On a PC gt PPC transfer KTERM will expect the files in the specified directory Environment variables are a feature of MS DOS and are a method of passing information to executing programs To set the above environment variable place the command SET KTERMFILES C KTERM TRANSFER anywhere in your AUTOEXEC BAT file and reboot your PC To cancel the KTERMFILES environment variable remove the command from AUTOEXEC BAT and reboot the PC Alternatively a temporary cancellation can be achieved by typing SET KTERMFILES at the MS DOS command line this also deletes the KTERMFILES environment variable Note from the above examples that the Y at the end of the KTERMFILES path specification is optional this is a common point of
31. of arrays would be advantageous is with an array of Booleans but this is more naturally expressed as a set when packing is required 6 6 PPC PASCAL ARRAYs and SETS The base type of a set may have up to 256 elements This enables SETs of CHAR to be declared together with SETs of any user enumerated type Note however that only subranges of integers can be used as base types All subsets of integers are treated as sets of 0 255 Full arrays of arrays arrays of sets records of sets etc are supported Two ARRAY types are only treated as equivalent if their definition stems from the same use of the reserved word ARRAY Thus the following types are not equivalent TYPE tablea ARRAY 1 100 OF INTEGER tableb ARRAY 1 100 OF INTEGER So a variable of type tablea may not be assigned to a variable of type tabl eb This enables mistakes to be detected such as assigning two tables representing different data This restriction does not hold for the special case of arrays of a String type since arrays of this type are always used to represent similar data See the Strong TYPEing section for more information Pointers PPC PASCAL allows the creation of dynamic variables through the use of the Standard PASCAL procedure NEW see the Predefined Idenfifiers section A dynamic variable unlike a static variable which has memory space allocated for it throughout the block in which it is declared cannot be referenced directly through an identi
32. of control C 0x03 anywhere Pure and simple O All input functions wait i e hang until the appropriate number of chars has been read from the PPC input queue If this is not desired use an input queue test like ipqcount to check the queue before reading The PPC has a 255 byte input RX queue for each port e All output functions wait i e hang until the appropriate number of chars has been written to the PPC output queue If this is not desired use an output queue test like opqspace to check the queue before writing The PPC has a 60 byte output TX queue for each port O There are no stdin stdout functions like getch getchar putch putchar getc putc etc etc whose precise operation e g trapping of 0x03 differs from compiler to compiler in any case O In porting C to the PPC the emphasis has been on simplicity while providing everything that is needed to build the most complex datacomms applications The following are the only single character 1 0 functions provided char fgetc int port returns a char from specified port int fgetcnd int port as above non destructive i e does an ungetc int fputc int port char char outputs a char to specified port The following are simplified character oriented versions of fwrite and fread int fwritec int port char bufname int charstowrite int freadc int port char bufname int charstoread 12 2 C Reference The number of char
33. of the extra i characters and press DEL Save the edited program and exit the editor with ctrl k x and re compile with the Compile and Run function The following correct output will appear after the successful compilation listing 012345 6 2 PPC PASCAL Special features of PPC PASCAL The term standard PASCAL used in this Manual refers to the original PASCAL language as defined by its inventor N Wirth and as generally taught in educational establishments PASCAL is a popular teaching language However the original PASCAL was not very useful on the smaller personal computers which have appeared since the late 1970s mainly because it had little support for the highly interactive input and output and other useful functions available on those computers This has led to various dialects of PASCAL and today 1992 arguably the most popular personal computer version is Borland s Turbo Pascal which has a large range of language extensions particular to the IBM PC platform PPC PASCAL is best described as standard PASCAL with PPC specific extensions and with a few of the standard PASCAL features not implemented PPC PASCAL extensions have little in common with the extensions in Turbo Pascal and Turbo Pascal programs which make full use of special features of Turbo Pascal are not portable to PPC PASCAL without significant changes The areas where PPC PASCAL differs from standard PASCAL are 1 PPC specific extensi
34. or PRINT statements Also direct commands such as LIST may be in either case but the entire command must be in the same case e g LisT is not allowed BASIC 5 1 Numbers All numbers are 16 bit integers and must always be in the range 32767 to 32767 Variables All variables are stored as 16 bit integers Variable names are single letters in the range A Z inclusive In addition to the 26 possible A Z variables a single array called is provided which can hold up to 2000 integers and whose elements are numbered 0 to 1999 All variables are set to zero whenever PPC BASIC is entered However variable values are retained when a program s execution is terminated allowing the variables to be examined to assist debugging Functions ABS X returns the absolute value of X RND X returns a pseudo random number between 1 and X inclusive SEED X sets a seed for the above pseudo random sequence GET P returns a character from port P or 1 if no character was waiting WGET P as above but waits until a character arrives ADC C returns a reading from channel C of the analog digital converter ADC U SWI S returns the status 0 1 of the PPC front panel switch S Arithmetic and Compare Operators Divide Note that with integers 7 10 0 and 10 3 3 Multiply Subtract Add Compare if greater than Compare if less than Compare if equal to Compare if not equal to Compare if greater than or equal to Compare if les
35. referenced indirectly by a static variable of type pointer which contains the address of the dynamic variable See PASCAL Dynamic Memory Allocation for more details of the use of dynamic variables When specifying elements of multi dimensional arrays you are not forced to use the same form of index specification in the reference as was used in the declaration For example if variable a is declared as ARRAY 1 10 OF ARRAY 1 10 OF INTEGER then either a 1 1 or al1 1 may be used to access element 1 1 of the array FACTOR unsigned constant variable expression E O He expression nor factor ij expression expression Mi See EXPRESSION and FUNCTIONS for more details 6 10 PPC PASCAL TERM The lowerbound of a set is always zero and the set size is always the maximum of the base type of the set Thus a SET OF CHAR always occupies 32 bytes a possible 256 elements one bit for each element Similarly a SET OF 0 10 is equivalent to SET OF 0 255 SIMPLE EXPRESSION The same comments made in TERM above concerning sets apply to simple expressions EXPRESSION simple expression simple expression When using IN the set attributes are the full range of the type of the simple expression with the exception of integer arguments for which the attributes are taken as if 0 255 had been encountered The above syntax applies when comparing strings of the same length pointers and a
36. runtime library for the ANSI C cross compiler kit 96 suffix Additional RAM accessible from C as a 96k random access file This memory can also be battery backed using a Dallas Smart Socket DG1 suffix Digital Parallel I O Card 16 TTL level inputs plus 16 high current open collector outputs Accessible from Pascal and C See the DG1 1 0 Card chapter A suffix Analog Subsystem 16 bit 8 channel analog digital converter ADC The Analog Subsystem itself consists of a number of options which include optional D A converters and other features See the Analog Subsystem chapter The model and any options are marked on the underside together with the serial number Customer specific options can be implemented subject to a reasonable quantity These can be in the form of special PPC Pascal and C runtime functions or as an option board such as the Analog Subsystem or the DG1 Digital Parallel I O Examples of customer produced designs are 1MB FLASH cards and C cards PPC E This is the Eurocard variant Due to the surface mount construction most of the above PPC 4 options are fitted as standard namely the R H2 C 96 The only presently applicable option is H3 PPC Overview 1 3 Get Started This chapter is a brief tour around the PPC You will create a simple BASIC program use the Editor create a simple PASCAL program use some of the Executive functions and finally create a simple standalone protocol conversio
37. specifying the PLACES variable _RORC char rotate right FUNCTION _RORC VALUE PLACES CHAR CHAR This rotates VALUE right by PLACES bit positions and returns the char result Any carry from bit 0 is fed back into bit 7 Only the three least significant bits of PLACES are used limiting it to 0 7 See the _BITC function for information on specifying the PLACES variable STRCMP compare strings FUNCTION STRCMP S1 S2 INTEGER INTEGER This compares string S1 with string S2 Both strings are assumed to be terminated with 0 The return value is negative zero or positive if S1 lt S2 S1 S2 S1 gt S2 respectively Note that S1 and S2 are addresses of the strings var s1 s2 array 1 20 of char init sl Hello 0 init s2 Hellq 0 writeln port1l strcmp addr s1 addr s2 produces a result of 2 whose sign indicates that s1 lt s2 Note that the magnitude of the result is simply the difference between the mismatched characters STRNCMP compare strings n chars FUNCTION STRNCMP S1 S2 N INTEGER INTEGER This is as STRCMP but only the first N characters are compared Referring to STRCMP example above writeln portl strncmp addr s1 addr s2 4 result 0 writeln portl strncmp addr s1 addr s2 5 result 2 MEMCPY memory copy PROCEDURE MEMCPY SOURCE DEST BLOCKSIZE INTEGER A block of bytes size BLOCKSIZE is copied from SOURCE to DEST The source and destination blocks may overlap No checking
38. takes place on any of the input values Example var block1 block2 array 1 20 of char init block1 3 hello memcpy addr block1 3 addr block2 11 5 6 36 PPC PASCAL After the above is executed block2 contains where represents an undefined character TOUPPER convert to uppercase FUNCTION TOUPPER INCHR CHAR CHAR lf the character INCHR is in the range a to z it is converted to uppercase CBRK check for a break character OBRK output a break character FUNCTION CBRK PORT TEXT BOOLEAN PROCEDURE OBRK PORT TEXT The above functions work on ports 3 and 4 only They are not supported on a PPC 2 The above functions support detection and generation of line break conditions A break is a sequence of 1 bits on the line whose duration exceeds the duration of a complete character at that baud rate A break therefore represents a framing error Breaks are used with some equipment to indicate a special condition The PPC checks for a break condition in the UART on P3 amp P4 only every 1ms and latches any break condition in a flag CBRK returns the state of this flag and clears the flag CBRK may therefore fail to detect a break if the break duration is less than 1ms OBRK outputs a break of a fixed duration 200ms regardless of the current baud rate PPC break condition checking As well as using CBRK you can detect received break conditions through the reception of
39. the break was detected and passes control to the Executive When enabled this check is made at the beginning of all loops procedures and functions Thus you may use this facility to detect e g which loop is causing the program to hang However break checking is not implemented in some 1 0 loops e g it will not work if your program is hanging because an output port has been prevented from transmitting by a BUSY handshake from the receiving device The only exit then is to reset the PPC or to write the program to check the handshake before outputting and if BUSY check if a CTRL C character has arrived on Port 1 If C is selected then the check is not made resulting in higher execution speed If after your program has started executing you have pressed any key other than ctrl c then the break checking will cease to function This is because the ctrl c character 3 is seen as a break character only if it appears af the front of the Port 1 input queue The only way to stop a program in such a case is with the front panel reset SW2 SW3 Obviously one way to keep break working is to regularly read from Port 1 Break checks are automatically disabled on autoexec programs regardless of the setting of this option However for the highest execution speed C should still be selected PPC PASCAL 6 45 Option U When this option is selected lowercase and uppercase are not treated as equivalent U or just U by its
40. the port s CTS DSR or CDI input signals to be read The states are read into a record containing the following four members rppc_port portl port2 port3 port4 cts_in boolean dsr_in boolean cdi_in boolean The following Port 3 example shows how to read the states of the CTS DSR CDI signals for Port 3 var anyname readhsktype give the record a name retcode integer this accepts any readhsk errorcode anyname rppc_port port3 initialise the Port to read 1 2 3 4 retcode readhsk anyname this fills in the signals states with anyname do print out the states writeln portl CTS cts_in DSR dsr_in CDI cdi_in IPQCOUNT get bytes in input queue FUNCTION IPQCOUNT PORT TEXT INTEGER Each PPC port has a 255 byte input queue which receives data under interrupts If there is any unread data this function will return an integer in the range 1 255 In practice if the handshakes are operating correctly the queue size should never exceed 128 by more than a few chars For full details of the serial port queues see the PPC Ports chapter This function allows a program to check if any data has arrived on a specified port s input queue It allows a program to read data only when data is present rather than hang until data arrives When used in conjunction with the PPC timers this function permits the construction of a program which waits for input data for a certain maximum period and then t
41. the program with ctrl c For full details of the PASCAL compiler please see the PPC PASCAL chapter To be useful most practical data stream processing PPC programs must loop forever and never terminate For maximum performance your finished program should have runtime break checks disabled See PPC PASCAL chapter for details of compiler options KTERM users if you reset or power down the PPC you should exit KTERM with alt x and re invoke KTERM after the PPC s EXE LED starts flashing again e In PPC firmware v1 07 the Compile and Run function can also be used to execute a binary i e compiled C program Previously the only way to run those was to mark them autoexec and reboot 6 File utilities Pressing when this item is highlighted enters the following menu PPC74 File Utilities AL_PAOG Pasca 764 ADCTEST Basic 245 CALCOMP Pascal 11071 Display program head CUTDATA Pasca 131 gt DACTEST Pasca 357 Copy program EDTTOEMO Basic 145 Delete program EEPROM Pasta me poea Delete ALL programs PLOT_DRY Basie 14024 Set passunrd SET PIRT Pasra 211 Encrypt program TOBPPER Pascal 100 Decrypt program TSTCLBCK Pasta 18 Bites 259051 space Jb h Function Program Selector Selector 6 1 Display program head This function can be used to display the first 24 lines or 42 49 lines if using KTERM with VL option with EGA VGA of a program lt allows a quick identification of what the program doe
42. them and finally to produce a standalone protocol converter which can be left in place PORT 1 ANSI compatible terminal PORT 2 MULTI PORT COMMUNICATIONS PPC EXECUTIVE PASCAL Compiler BASIC Interpreter PROCESSOR o gt RS232 RS422 RS485 Program Editor FORTS E SERIAL PORTS File Utilities amp Security PORT 4 An ANSI compatible dumb terminal is the only additional equipment that is required and it can be disconnected once the program is finished All PPC configuration is done via the terminal there are no internal switches The high level languages provided are integrated into the PPC in a way which eliminates any need for directly accessing the PPC hardware and greatly simplifies the creation of datacomms programs The programmer does not need any knowledge of the hardware and low level software involved in the PPC An ANSI C cross compiler is also available with a runtime library specially modified for the PPC Each of the serial ports supports the full set of asynchronous modem handshake and control lines and can be connected to most computers printers plotters modems and other devices Each port can be configured for RS232 RS422 or 2 wire or 4 wire RS485 operation The filing system stores up to 20 BASIC PASCAL or binary compiled C programs in non volatile semiconductor EEPROM memory which uses no batteries and has a typical retention time of 100 years Any one of the pr
43. turn to the PPC Pascal section and check the description of the corresponding PPC Pascal function if present for a more detailed description Note that Hi Tech C supports comments with the C sequence as well as the more commonly used sequence For usage examples of all PPC specific functions see the supplied test c program 1 0 Read Write Functions The 1 0 has been implemented similarly to PPC Pascal the four PPC ports correspond to four streams called port 1 port2 port3 port4 These streams are supplied as the first parameter to each of the various C 1 0 functions provided For convenience the supplied ppclib h file defines the symbols port1 port2 port3 port4 as 1 2 3 4 These streams are not like disk files They are in fact much simpler to understand and use O Since data flowing through the PPC is continuous you will never get EOF returned by any 1 0 function This is why most of the PPC specific character based functions use type char not int to represent character data this also produces more efficient code The standard C file behaviour reading what there is to be read and then getting EOF is generally not useful in a datacomms product because you would be getting EOF very frequently whenever you have emptied the input queue All 1 0 is binary there is no built in conversion of LFs to CRLFs no trapping of CRs no hidden buffering of input until a CR arrives no trapping
44. which floating point numbers are represented in binary is complex and beyond the scope of this Manual The floating point format used is not the IEEE floating point format sometimes used in microcomputers and it is therefore extremely unlikely that you will be able to communicate using binary reals with BREAD or BWRITE with another piece of equipment The only situation in which you might be reading or writing binary reals is when two or more interconnected PPCs need to communicate floating point values to each other in the most efficient manner possible If floating point data must be exchanged with external devices the text format i e using READ or WRITE for the 1 0 should normally be used this requires more CPU work but at least the fextua representation of floats is universal Records and Arrays Records use the same amount of storage as the total of their components Variant records use the amount of storage required by their largest variant different variant parts use the same storage Arrays if n number of elements in the array s size of each element then the of bytes occupied by the array is n s Examples an ARRAY 1 10 OF INTEGER requires 10 2 20 bytes an ARRAY 2 12 1 10 OF CHAR has 11 10 110 elements and so requires 110 bytes PPC PASCAL 6 57 Sets Sets are stored as bit strings and so if the base type has n elements then the number of bytes used is n 1 DIV 8 1 Examples aSET OF CHAR requires 256
45. which specifies the total number of characters to be output If m is not sufficient for e to be written or m is not present then e is written out in full with a trailing space and m is ignored Note that if m is specified to be the length of e without the trailing space or e 0 or e 1 then no trailing space will be output 2 e is of type INTEGER and the form lt e m H gt is used In this case e is output in hexadecimal If m 1 or m 2 then the value e MOD 16 m is output in a width of exactly m characters If m 3 or m 4 then the full value of e is output in hexadecimal in a width of 4 characters If m gt 4 then 6 16 PPC PASCAL leading spaces are inserted before the full hexadecimal value of e as necessary Leading zeroes will be inserted where applicable Examples WRITE port1 1025 m H m 1 outputs 1 m 2 outputs 01 m 3 outputs 0401 m 4 outputs 0401 m 5 outputs 0401 3 e is of type real The forms lt e gt lt e m gt or lt e m n gt may be used The value of e is converted to a character string representing a real number The format of the representation determined by n If n is not present then the number is output in scientific notation with a mantissa and an exponent If the number is negative then a minus sign is output prior to the mantissa otherwise a space is output The number is always output to at least one decimal place up to a maximum of 5 decimal places and the exponent is always signed either with a plu
46. which you think the PPC might be set to and use KTERM with the ni option SETSER C0M1 38400 N 8 1 KTERM COM1 NI If the mi option is used any baud rate specified on the command line is ignored OV_ This override option forces KTERM to connect to the specified serial port even if that port appears to be in use by another program e g a mouse driver Some PCs initialise their COM1 COM2 interrupt vectors to point KTERM 7 3 to memory addresses below F000 0000 i e possibly to a memory resident pro a port already in use message and aborts This option overrides the checking An example of where the ow option is commonly required is when your gram and KTERM then issues CONFIG SYS file contains a STACKS A B command where A or B are non zero This is likely to be the case if you have installed Windows 3 1 or are using DOS version 5 or higher IL This option logs copies everything sent to the screen to a file called KTERM LOG located either in the current directory or in the KTERMFILES path It is useful for technical support assistanc to zero size whenever KTERM is invoked KTERM examples KTERM use COM1 at 9600 baud KTERM COM2 use COM2 at 9600 baud KTERM COM1 38400 use COM1 at 38400 baud KTERM COM1 38400 vl use COM a a a 1 at 38400 baud with a 43 or 50 line di m a a KTERM b19200 m use COM1 at 19200 baud force a monochrome d KTERM b19200 mi use COM1 at 19200 baud forc
47. 0 73 65 72 69 61 6C 20 6F 72 74 20 63 6F 6E 66 serial port con 000020 69 67 75 72 61 74 69 6F 6E OD OA OD OA 20 20 20 figuration 000030 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 To exit the input hex dump mode press any key When using this function to view data flowing along a cable between two devices neither of which is the PPC remember to connect only PPC s pins 3 RX and 1 7 ground Do not connect up any PPC handshakes doing so could cause contention However this means that only the first 255 bytes of the hex dump may be reliable 10 4 Serial port tests Pressing J when this item is highlighted invokes a very thorough loopback test which checks all data handshake and modem control lines on all two PPC 2 or four PPC 4 serial ports This test requires the following 1 The terminal PPC cable must cable recommended in Serial Ports and Cables chapter This already contains the required Port 1 loopback connections at the PPC end of the cable 2 All PPC ports other than Port 1 must be fitted with special loopback adaptors See the PPC Serial Ports chapter for wiring details of these adaptors If this test reports any errors then either your loopback adaptors are faulty or the PPC is faulty The most likely cause is a port blown up by overvoltage or by a powerful electrostatic discharge 10 5 Printer config Pressing J when this item is highlighted displays a function which allows a printer initialisat
48. 0 loads a real number is above 32767 INIT does not perform type checking You can load anything anywhere Also INIT does not prevent the loading of data into addresses past the end of the variable Because of the lack of error checking use INIT with great care and if in any doubt print out the contents of the variable s to check that the result is what you intended Examples 6 32 PPC PASCAL var c array 1 11 of char init c hello there fills the array with the 11 chars init c 1 hello there as above init c hello there as above init c 104 101 108 108 111 20 74 68 65 72 65 as above init c 104 101 108 108 111 20 74 68 65 72 65 as above f init c hello init c 7 hello var array 1 4 of integer init i 2 23 234 0 init i 3 10000 11000 var r array 1 4 of real init r 1 0 2 5 3 4 245 56E6 Any PPC PASCAL variable can be initialised with INIT including records and sets Also for longer statements the constants can be spread over multiple lines var rec record m array 1 8 of char n array 1 4 of integer p integer q array 1 4 of real end ills in 1st 5 chars only 1 5 fills in the last 5 chars only 7 11 a oS ills the array with the 4 integers ills in elements 3 and 4 only ills the array with the 4 reals initialises member m in
49. 1 DIV 8 1 32 bytes a SET OF blue green yellow requires 3 1 DIV 8 1 1 byte Pointers Pointers occupy 2 bytes which contain the address in Intel format low byte first of the variable to which they point 6 58 PPC PASCAL Recommended Books The Pascal books below are useful for learning the language Most Standard Pascal books devote large sections to teaching the more elegant aspects of Pascal programming which are likely to be rarely used in datacomms work so almost any book which describes the main elements of the Standard Pascal language will be useful The major differences between PPC PASCAL and Standard Pascal are in the area of 0 and for details of these you must consult the relevant sections in this chapter You should avoid books which describe Borland Turbo Pascal This version of Pascal has many IBM PC specific features and is quite different from PPC PASCAL Tutorial Style Books Jim Welsh John Elder Introduction to Pascal 3rd Edition 1988 Prentice Hall ISBN 0 13 491549 6 A thorough overview of Pascal with examples and exercises Many examples of more complex programs Not recommended for a complete novice to programming S Eisenbach C Sadler Pascal for Programmers 1st Edition 1981 Springer Verlag ISBN 0 387 10473 9 and 3 540 10473 9 A good readable introduction to Pascal with examples but not very useful for 1 0 Richard Meadows Pascal for Electronics and Communications 1st E
50. 1 ms RX Handshakes When the PPC port is receiving data if the free space in its 255 byte RX queue falls below 128 bytes it sets all enabled RX handshakes to the BUSY state A BUSY state is an RS 232 low level and if XON XOFF is enabled the transmission by the PPC of an XOFF character When the space in the RX queue increases above 200 bytes as a result of a user program removing the data from it all enabled handshakes enter the READY state RX handshakes which may be enabled are RTS DTR and XON XOFF More than one RX handshake may be enabled From the above it is clear that when a device which is sending data to the PPC is told by the PPC to stop transmitting it must not transmit more than 128 additional bytes after that otherwise data may be lost The above mentioned XON XOFF characters can be transmitted by the PPC only if all enabled TX hardware handshakes are READY Binary Data Handshaking When transferring binary data XON XOFF characters could appear accidentally within the data In such cases an XON XOFF handshake in which the XON XOFFs flow in the same direction as the data must be disabled For example if a PPC port is receiving binary data that port s TX XON XOFF handshake must be disabled If a PPC port is transmitting binary data the receiving device s TX XON XOFF handshake if available must be disabled If two devices are exchanging fu l duplex binary data XON XOFF handshake cannot be used at all Failur
51. 24 basic mode 42 EGA with VL or 49 VGA with VL These figures are one less than expected because of KTERM s permanent status line Typing Modes There are two basic modes INSERT and CHANGE INSERT is the normal method of text entry When you type a character in INSERT mode all of the line to the right of the cursor is moved right one position before the character is inserted The current line becomes longer by one character In CHANGE mode the new character overwrites the current character at the cursor and thus the line remains the same length You are not allowed to go over the end of the line in CHANGE mode In general INSERT mode is used to build up a file and CHANGE mode is used to alter small sections within a line The Editor 4 1 Editor Commands All editor commands start with a control character This is optionally followed by additional characters To enter a control character type the character while holding down the CTRL key For example to generate a CONTROL K also shown as CTRL K press and hold the CTRL key press the K key CAPS LOCK state is irrelevant release the K key and only then release the CTRL key Do not press CTRL S while you are in any of the Executive functions these include the editor the compiler BASIC or a PASCAL program running from Compile amp Run CTRL S is an XOFF which will stop all output to the terminal until a CTRL Q XON is pressed If you are using KTERM and you exit KT
52. 3 CRCBUF compute a CRC over a buffer o o o o ooooo o 6 33 ABI me gernDitiest ts da ro ds do ASA ts hen 6 34 _AND integer bit wise AND o o o o ooo 6 34 JOR integer bit wise OR o a do 6 34 _XOR integer bit wiseXOR o o ooo 6 34 _CPL integer bit wise complement o oo 6 34 _SHL integer shift left 0 ooo o 6 34 _SHR integer shiftright o ooo 6 34 _ROL integer rotate left o ooo 6 35 _ROR integer rotate right a 6 35 ABITG Car Dices Era a o tr a bao Maat ates 6 35 ANDO char bit wise AND dial ii A tod 6 35 LORG O a a IN 6 35 KORG char bitwise XOR o esac manian aiea a Baw wars As aa 6 35 _CPLC char bit wise complement a a aa es 6 35 SAA a eel one oe Deg Dade 6 36 SHARON e al ets Ae eet lod eee Salon ewes a eh 6 36 ROEG char rotate l ft i isc ase ae Ret ae BOL he ae Hell i a oes 6 36 SRORG ICAC Mae tds Bik eee AS A os ea Gelb 4h Bn Reds 6 36 STRCMP compare strings ee 6 36 STRNCMP compare strings n chars o ooa aaa ee 6 36 MEMCPY memory copy 0 o o 6 36 TOUPPER convert to uppercase 4 4 a Bleak i 6 37 CBRK check for a break character OBRK output a break character 2 es 6 37 PPC break condition CheckiNG ooo 6 37 Analog Subsystem PASCAL functions a a dee Se Aa 6 38 ADCINI initialise ADE a od o lo ida Me 6 38 ADC read a
53. 485 2 wire or 4 wire PPC D connector pin numbers shown here refer to the PPC 4 male 9 way connectors only Hardware Interface RS232 All four ports have an identical interface which supports the full set of RS 232 data and handshake signals The following diagram shows the PPC connected to an RS 232 peripheral device which could be a computer a printer plotter a modem or almost anything else PPC 9 way PERIPHERAL 5 GND GND 147 vR TX DATA 2 PX annals X 2 as ES HANDSHAKE aie eee HANDSHAKE moi Tal ie cae HANDSHAKE MODEM CONTROL cate E HANDSHAKE MODEM CONTROL ae ie See MODEM CONTROL Di o MODEM CONTROL ae All supported signals are shown connected However with most devices only a subset of the connections shown will be required depending on the handshake requirements The only common device which might use all of the supported signals is a modem see Modem Handshaking Pin Functions GROUND TX RX RTS CTS DTR This signal must always be connected This combines both Protective Ground and Signal Ground functions Transmit Data output A write statement transmits data from this pin subject to all enabled TX handshakes being READY Also when XON XOFF is enabled as an RX handshake XON XOFF characters are generated by the PPC and are transmitted from this pin to control the data flow into the RX input Receive Data input A read statement reads data arriving
54. 5 8 DN Spot ic fr A O ab ae ea ata ar deh os Annee 5 8 MAA Sethe Nod Eas do em Ae os I ce A deta lee Aen E 5 8 BYERS YST EM ty sath Gatctes a a a cda 5 8 Programming EXAMBIGS 2 4 tg 2 take dw elt ea Fa Obed owe SE Te on eek a Pas 5 9 SPEED AE ha rr Bintan Rh ee A Woe T Ade A A ae A dy he aya TA 5 9 Pe eS 2p foie yi or A ar A AAA EA 6 1 Whatis PPG PASCAL 26 wurde it Sed jak bow ea dha la ACG ae ee eae de 2 6 1 EXAMPIGS oct det op BREE bo ted ete 2M ay WE dy ft a 6 1 How am going to learn PASCAL 1 o o o 6 1 How to create edit and compile a PASCAL program o ooooooo o o 6 1 PPG PASCAL Introductions a ca als Pde aa at dida id de a dde 6 2 A QUEK Program seins e a A AOR eee a tt de td ae AD d 6 2 Special features of PPC PASCAL bs e a a Bel SO A A dela e 6 3 GOMPUEFLISUNO ainda lat t t Ap by tech ooo a o BOO asa 2a 6 3 PPC PASCAL Syntax and Semantics o o o 6 4 DENTPIENS curras rra Seen tal aye ae doen Road ge to A 6 4 UNSIGNED INTEGER 4 ies pri o Nasa seal tin BAS 6 4 UNSIGNED NUMBER ratas teas m devas oe oil Roth tate aaa oe a RNA 6 4 UNSIGNED CONSTANT o Praia dre Ed aabt 6 5 CONSTAND unite a RA eRe a a SURE oe Ne 6 5 CHARACTER SU BRINGS ade ceed eet de atch eek Suan Sab a BHR ade de GeO y 6 5 NA at Mah cade ah Ms E hd oe IA 6 6 Teich in Oot bade IE RA IE ancien Mh ab 6 6 ARRAYS aNd SETS bee o tele de tab Wet ond eae hee es AN hoe ok 6 7 PONES vise ce A a Malis ia ctrl ide tall Det Aa te
55. 9 and no further All other commands will work as normal if the number of lines exceeds 9999 although note also that the average number of characters per line would have to be about three for the line numbers to exceed 9999 PPC program files are stored as text lines terminated by a CRLF There is no end of file marker When a file is read into the editor the LFs are stripped out and when the file is saved they are inserted back in This makes better use of the available memory However it is possible to edit a file which is too large to save only when the LFs are inserted This is very unlikely to happen but when it does you will be advised the number of excess lines which must be deleted before the file can be saved In general the maximum file size which can be edited is similar to the maximum file size which can be stored in the filespace which in turn is similar to the maximum source file size which when compiled produces the maximum allowed amount of binary code The various parts of the PPC have comparable capabilities Non Printing Characters You should never insert control characters into program files They can cause errors which can be extremely difficult to find Characters of ASCII value less than 32 decimal control characters are treated as any other character They may be entered into the file by pressing the control meta key CTRL P and then the control character desired The meta key may also be used to speci
56. ADOR osa a de Deke Ah da Pa Aan Ah ele 6 22 SIZE A E RN RN 6 22 EAS O O orcos al A a rd denia at bad Eg 6 23 a IA Bead A asian at ete 6 23 PASCAL Dynamic Memory Allocation 0 o ooo 6 24 A E E NI mF EA 6 24 DIS USES ad is et Pl rd at Mote od ee do e 6 24 AA IA E O fatto de 6 24 A AN A Ud Ad 2 ar tah 6 24 SA O E 6 25 ts A A We emia dey Bowley Who io A eae i eti 6 26 SETPORT configure a serial port o oo o o 6 26 READPORT get serial port configuration 0 o o 6 27 SETHSK control handshake outputs o o o 6 27 READHSK read handshake inputs o o o oo 6 28 IPACOUNT get bytes in input queue ooo oo 6 28 IPQCLEAR clear input queue o oo o 6 28 OPQSPACE test output queue space o a o o 6 28 OPQCOUNT get bytes in Output queue o 6 29 SETRTC set real time clock e e a a 6 29 GETRTC read real time clock ooa aaa 6 30 LOADTIMER load a timer noaa aa aa 6 30 READTIMER read a timer aaa 6 30 OLED control user LED oy 2 mrg aa ta od 6 31 READSWI read front panel switches a 6 31 VAL converta NUMDEN s cara a nae a ee aR he ed bE A 6 31 INE FS initialiSe data n coo hac aed wo as Wt at ong Seals ls Gah ade te pla a 6 32 SUMBUF compute a checksum over a buffer oo o o o 6 33 XORBUF compute a XOR over a buffer o o o oo o 6 3
57. ADSWI read front panel switches PROCEDURE READSWI VAR R SWITCHTYPE This procedure allows the three front panel switches to be tested Their states are returned in a record of type SWITCHTYPE containing three Boolean variables which are TRUE if the switch is being pressed FALSE otherwise The record contains the following members SWISTAT BOOLEAN SW2STAT BOOLEAN SW3STAT BOOLEAN The following example program prints out the current states of the switches var anyname switchtype give the record a name readswi anyname get the switch states into the record with anyname do output them writeln portl SWl swlstat SW2 sw2stat SW3 sw3stat Note that if SW2 and SW3 are pressed together for more than approximately 1 second the PPC will be reset This cannot be disabled by any program VAL convert a number PROCEDURE VAL VAR STRING VAR I INTEGER VAR NEXTPOS INTEGER VAR SUCCESS BOOLEAN PROCEDURE VAL VAR STRING VAR R REAL VAR NEXTPOS INTEGER VAR SUCCESS BOOLEAN This procedure converts an ASCII character string representing an integer or real number into the numbers binary equivalent It is useful if e g your program has read in a line of text containing numbers into an array without conversion and the numbers then have to be read It performs the same operations as the READ procedure when reading integers or reals except that READ converts the characters as they are being received and can
58. C Note that modems use a different pin naming convention from most serial devices Modems are DCE devices which means that TX RTS DTR are all inputs and RX CTS DSR are all outputs the opposite of almost everything else PPC Serial Ports 8 7 Port Parameters A range of serial parameters is supported by each port These can be configured in two ways 1 From the Executive Runtime Port Config menu The settings done here are non volatile and are stored until again changed in this menu 2 From a PASCAL or C program using the SETPORT or setportcfg functions respectively The settings done here are volatile and are lost at power down Due to slight differences in the internal hardware implementations of the ports not all possible parameters can be configured on every port The table below shows the valid combinations PORT 1 PORT 2 PORT 3 PORT 4 30 37 5 50 75 100 110 30 37 5 50 75 100 110 134 5 150 300 600 134 5 150 300 600 a soo 1200 2400 4800 S00 600 1200 2400 4200 2000 2400 3600 1200 2000 2400 3600 9600 19200 38400 38400 4800 7200 9600 4800 7200 9600 19200 38400 57600 19200 38400 57600 115200 115200 bits word 78 78 5678 5678 parity none even odd none even odd none even odd none even odd stop bits 12 12 12 12 RX RTS h shake on off on off on off on off RX DTR h shake on off on off on off on off RX XON XOFF h shake on of
59. CTION _ROR VALUE PLACES INTEGER INTEGER This rotates VALUE right by PLACES bit positions and returns the integer result Any carry from bit 0 is fed back into bit 15 Only the four least significant bits of PLACES are used limiting it to 0 15 _BITC char bit test FUNCTION _BITC VALUE BITNUM CHAR BOOLEAN This returns the state of a bit in a character as TRUE or FALSE if the bit is 1 or 0 respectively Only the three least significant bits of BITNUM are used limiting it to 0 7 Note that the bit number is specified as a char so for example if you want to test bit n where n is held as an integer the chr function must be used to convert the integer into a char var n integer c char state boolean state bitc c chr n The bit number can of course be specified as an immediate value using the operator state bitc c 6 test bit 6 _ANDC char bit wise AND FUNCTION _ANDC VALUE1 VALUE2 CHAR CHAR This performs a bit wise AND of the 8 bits constituting the two chars and returns the char result For example var a char a _andc a 0F zero top four bits _ORC char bit wise OR FUNCTION _ORC VALUE1 VALUE2 CHAR CHAR This performs a bit wise OR of the 8 bits constituting the two chars and returns the char result For example var a char a _orc a 0F set lowest four bits _XORC char bit wise XOR FUNCTION _XORC VALUE1 VALUE2 CHAR CHAR This performs a bit wise XOR o
60. DOM FUNCTION RANDOM REAL This returns a pseudo random real number between 0 0 and 1 0 The algorithm used is based on that of B A Wichmann and I D Hill NPL Report DITC 6 82 Normally the same random numbers are generated by RANDOM for each run of a program the seeds may be changed using the procedure RANSEED described above SUCC X X may be of any scalar type except real and SUCC X returns the successor of X SUCC A returns B Ssucc 5 returns 6 PRED X X may be of any scalar type except real the result of the function is the predecessor of X PRED j returns PRED TRUE returns FALSE ODD FUNCTION ODD X INTEGER BOOLEAN ODD returns a Boolean result which is TRUE if X is odd and FALSE if X is even ADDR V This function takes a variable identifier of any type as a parameter and returns an integer result which is the memory address of the variable identifier V For information on how variables are held at runtime in PPC PASCAL see the Data Representation and Storage section SIZE V SIZE is a special function whose parameter is either a variable name or a type identifier It returns as an integer the number of bytes of storage used by this type of variable Example WRITELN PORT1 SIZE INTEGER gives 2 6 22 PPC PASCAL RECAST e typ RECAST is a function for suspending the type checking in PPC PASCAL It takes any expression e of any type and uses it as if it was of type typ Both parameters mu
61. ERM with ALT X while in the editor any changes made to the file will be lost and when you run KTERM again you will be returned to the Executive Cursor Moving Commands The four cursor keys work as expected In addition the cursor can be moved with the following commands Character left right Use the cursor keys Word left right CTRL A CTRL F Characters that constitute the boundaries between words are pias EI ea a A o E amp TAB CR SPACE Tab left right CTRL OS CTRL 0 D Start End of line CTRL QS CTRL Q D With KTERM the HOME and END keys also perform the same function Line up down Use the T J cursor keys After moving up or down one line the cursor column remains fixed Thus it may appear that the cursor is positioned beyond the end of a line However if any other key is pressed the editor will behave as though the cursor was at the end of the current line This behaviour prevents the cursor always jumping to the end of each line and makes editing programs much easier Top Bottom of screen CTRL QE CTRL QX Move the cursor to the top bottom of the screen Page up down CTRL R CTRL C Start End of file CTRL QR CTRL QC This moves the cursor to the start end of the entire file 4 2 The Editor Text Deleting Commands Delete line Delete last character Delete this character Delete word left right Delete to start of line Delete to end of line Block Commands CTRL Y Delete the curre
62. ES k RX A user program never accesses a port directly any READ WRITE etc statements communicate only with the queues The transfer of data between a queue and its port is performed as a background process i e under interrupts by the comms processor and is transparent to the user program Transmit Queues A TX queue greatly enhances performance in both computational and datacomms areas by allowing a user program to perform computations while previously generated data is being transmitted under interrupts With the 64 byte TX queue a user program could theoretically generate up to 64 bytes of data even if the output device was BUSY throughout that time However to allow for insertion of XON XOFF characters into the data stream and other reasons the PPC limits the filling up of its TX queues to 60 bytes Receive Queues An RX queue is necessary to avoid data loss when handshaking the incoming data When the space in this queue falls below 128 bytes the PPC will return a BUSY handshake if enabled See the RX Handshakes description on the following page for full details PPC Serial Ports 8 5 aj aj Handshaking The PPC supports two types of handshakes transmit TX handshakes and receive RX handshakes A TX handshake signal is received by the PPC and controls the data flow from the PPC An RX handshake signal is transmitted by the PPC and controls the data flow into the PPC Each PPC serial port is equ
63. FF ON UFF UFF UN lse cursor keys to mave around SPACE ar or to change settings ESC exits and Saves any Changes Y restaures previously saved settings PORT 1 settings above apply naly while a proyrem is running As stated above this function configures the power up defaults This means that if you run a PASCAL program which reconfigures e g a port s baud rate then the new baud rate will remain until you either reboot the PPC reset it or power it down Ports cannot be reconfigured from BASIC If you have a two port PPC PPC 2 then the information for ports 3 and 4 will not be displayed Although all four ports function identically there are some differences between their capabilities due to differences in internal hardware implementation These are detailed in the PPC Serial Ports chapter but in summary Ports 3 4 support a wider range of baud rates etc Port 1 cannot be set to 300 baud the CTS handshake on ports 1 2 is permanently ON VERY IMPORTANT the Port 1 configuration defined in this function applies only when a program is running in the autoexec mode If a program is running within the Executive i e from Compile amp Run then the settings in the Executive Mode Port 1 config function apply instead 10 2 Config dump When this function is selected with J a menu of PPC ports appears This is followed by a menu of output devices currently supported types are ASCII Postscript and HPGL Pressing J at this poi
64. G Pesca Fot ADCTEST Tesic 95 gt CALSOMPL Pascal 11071 CUTDATA Pasca 11 DACTEST Pascal 19 EDIZOEMO Desio 145 Run selected program EEPROM asci 102 Enter Executive PLOT_DRY Desio 14024 SETPORT Pascal 11 TUUPPER lasca 100 TSTCLOCK Pescei 182 i Bytes 2905 syace 1b6b PPC action at power up z A Currently selected Select the poser up action end program press ENTER You can instruct the PPC to either automatically compile run autoexec the selected program or to always enter the Executive The selection is stored in non volatile memory When the PPC is configured to autoexec a program the only ways to enter the Executive are 1 lf the program terminates the PPC enters the Executive However a program which terminates will probably not be useful in most applications so this method is useful during program development only 2 Press all three front panel switches SW1 SW2 SW3 until RST illuminates and then while still holding SW1 release SW2 SW3 Wait until the EXE LED starts flashing again 8 Transfer PPC PC This function works only with the supplied KTERM EXE terminal emulator It will not work with any other terminal or terminal emulator program Pressing J when this item is highlighted instructs KTERM to display a prompt for a PAS BAS or BIN filename or a TAB key can be used to display a menu of such files Pressing transfers the selected file to the PPC and stores it i
65. NGE mode A character typed in INSERT mode is inserted into the line A character typed in CHANGE mode overwrites the current character A lt CR gt cannot be overwritten in CHANGE mode CTRL 0 Auto indent only operates in INSERT mode The message INSERT becomes I AUTO When indent is on and is pressed in INSERT mode the next line will be indented so that it starts at the same column as the line above it CTRL 0 F A following the amount of free space indicates that there is a block in the block buffer This function is used to display the size of the block The Editor 4 5 Miscellaneous Deliver tab Restore undelete line Disk directory Control meta key TAB or CTRL I Tabs are fixed at 4 column stops and will be entered as a ASCII 9 code in the file and will not be changed to spaces They are treated in the main like any other character in the file CTRL U f you are in the process of editing a line then this command will restore the line to what it was when you first positioned the cursor on it If you are not in the process of editing a line then this command will insert in front of the current line the last edited line This aspect of the command is useful because the DELETE LINE command places the deleted line into the line buffer exactly as though it had just been edited You may thus move a line from one place to another by deleting it moving the cursor to the desired place and then issuing a CTRL U comm
66. OPERATING MANUAL 3 e MS o Di a rd a a _ z Oreos y oe TP TS 0006852 opeeooo oston e oe C0008 ee er oomme i errors Ay K gt KK SYSTEMS LID SYSTEMS 01001011 01001011 00100000 01010011 01011001 01010011 01010100 01000101 01001101 01010011 Copyright 1992 2000 KK Systems Ltd No reproduction of any part of this document in any form is allowed without prior written permission from KK Systems Ltd All other copyrights and trademarks acknowledged The PPC is protected by patents Extract from Conditions of Sale Any electronic device or system can fail possibly resulting in the loss of valuable programs or data It is your responsibility to ensure that all such valuable material is backed up at all times We are not liable for any direct indirect or consequential loss caused directly or indirectly through the use of this product All our software is sold on an as is basis without a warranty of any kind We do not claim that this product is suitable for all potential applications It is your responsibility to verify that the product works in its intended application In the interest of progress we reserve the right to alter prices and specifications without prior notice Product versions This manual covers the following versions PPC firmware v1 07 dated 5 FEB 97 or later KTERM EXE v1 01E Edition 13 28 JAN 2000 c vpdocs2 english ppcman Tabl
67. PC is in the Executive Then invoke KTERM on the PC The Executive main menu will appear and should look similar to the following PPC74 Executive PPC C 1992 KK Systems Ltd Serial M 1201 AL_PROG Pasca 764 Interactive Basic ADCTEST Basic 245 Create program CALCOMP1 Pascal 11071 Edit program CUTDATA Pasta 131 Campile only DACTEST Pasca 35 EDITDEMD Basic 1452 File utilities EEPROM Pascal al Define power up artun PLOT_DRU Basie 14024 Transfer PPC PC SET PRT Pasra 211 Transfer PRC gt PC TOUPFER Tasral 100 CanPig amp diagnostics gt TSTCLBCK Pasta 182 Rehont the PIC Bites 23031 space J64h Function i Program Selector Selector Use cursor keys to mave around Or ENTER to select a function or program If the Executive menu does not appear With a terminal press ESC If this fails refer to the Troubleshooting information later in this chapter With KTERM exit KTERM with alt x and re invoke KTERM Repeat several times if necessary If this fails refer to the Troubleshooting information in the KTERM chapter The PPC Executive 3 1 PPC Executive Fundamentals Basic Principles The Executive is built around a Function Selector at the left hand part of the screen and a Program file Selector at the right hand part of the screen To select a particular program for subsequent operations such as editing or compilation use the gt key to place the highlighted bar into the program dire
68. PPC C 1992 KK Systems Ltd Serial M 1201 A1_PAOG Pasca 764 Interactive Basic ADCTEST Basic 245 Create program CALCOMP1 Pascal 11071 Edit program CUTDATA Pasca 131 Compile only DACTEST Pasca 35 EDTTDEMO Basic 1452 File utilities EEPROM Pasta zB Define power up artun PLOT_BRU Basie 14024 Transfer PPC PC SET PORT Pasra 211 Transfer PIC gt PC TOUPPER Pascal 100 CanFig amp diagnostics gt TSTCLBCK Pasta 18 Rehont the PIC Bites 29031 space Ibi Function s Program Selector Selector Use cursor keys to move acnund or ENTER to select a function or program Step 4 Executive operations With the TY cursor keys move the highlighted bar up and down With the lt cursor keys move the bar between the function selector on the left and the program selector on the right Pressing J while the highlighted bar is on the right merely selects that program for future operations Pressing J while the highlighted bar is on the left selects that function which with some of the functions can descend into another function menu You are free to examine the facilities provided pressing ESC always returns to the main Executive menu Get Started 2 1 Step 5 BASIC Highlight the Interactive Basic item and press J You are now in PPC BASIC and you will create a new program Type in the following simple program the comments on the right are not part of the program 10 PRINT READY 20 C WGET 1 wait for a chara
69. R ULED DOUT1 DOUT2 OBRK ADCGAIN DAC DACC MEMCPY PDOUT FUNCTION ABS SQR ODD RANDOM ORD SUCC PRED EOLN CHR SQRT ENTIER ROUND TRUNC FRAC SIN COS TAN ARCTAN EXP LN ADDR SIZE RECAST MEMAVAIL SETPORT SETHSK READHSK SETRTC GETRTC ANEERD ANEEWR NVRDBLK NVWRBLK NVREADC NVWRITEC NVREADI NVWRITEI READTIMER ADCINI ADC ADCC CBRK PDIN IPQCOUNT IPQCLEAR OPQCOUNT OPQSPACE SUMBUF XORBUF CRCBUF BIT _AND _OR _XOR _CPL SHL SHR ROL ROR BITC ANDC ORC XORC _CPLC SHLC SHRC ROLC RORC STRCMP STRNCPM TOUPPER Where a predefined identifier is longer than eight characters e g SETPORTTYPE you should use the full name even though the PPC Pascal compiler will ignore any characters beyond the first eight This rule is recommended because the supplied compression utility program KPACK EXE does not implement the 8 character limit and may erroneously compress abbreviated identifiers PPC PASCAL 6 51 Programming Examples Please look through the various programs supplied with the PPC both on the diskette and in the filespace They contain examples of how to invoke most of the PPC PASCAL functions and procedures The most important requirement of a datacomms product is a total absence of bugs f you are writing bug ridden PC based applications as many people are you can charge your customers for an upgrade every 6 months as ma
70. S 631 EXA gaJHrL vot SZ 68 Srez FELEZI ONS saixe oe i vz oT 1009NI ZN ENY EZ 8 ote ta zz 6 2 m4 1353987 39831 fo pz 0931 INT 0AS 51 6 8 0AS 0AS et INTLX3 riHvL 101 it tad lt oT vIDHOL 8 6 ST o lt 0 1 a ra vt gaJH Z ZEJHPL 9 S IJH El a491 sow DEI EN 20 zI s Ol4 08z IJH el pr a yt zu oe JS nn alsa a a at y 9 113 s hoya LL y E y ITHPL 101 6 8931 y ive 204 te geal vu 8 as 9 G5 sgy E vITHPL zr El agi F QaJHrZ ZEJHOL LH 5 Th sad EE o lt ELF SI 9 bart LE ZE 4 1 IJH S riu A ON seg gyo tas CEE ER oy aot E z ow SE eE vies 8 6 E Sip T jE vq 3 epee BLE o lt ozan awi ay z ES 031 gag pes rire ey E 131 sisi PD INI Lk a 6ergasvez ee 1048 al I nns t0 ied Lee vIJHPL 101 ZN Y 0 1 34 t lt 90 EEP zx I 430 8 el TT IJHYL 0N9 ce ra ua C EE o dd gt o1 et viJHee v E 358 i S s Fa ar y n ie 0 ap El ZT ET vIDHOL it 101 sz 00 aua H karat INTIXA ez st vpIDHPL E I 181 Ze EN zz 12 p aal o lt szal 20 ez 61 J E WRIA E ety agi Lo rere ong orni lt zo 91 sip IJHYL 3 5 01 E 0 vt el bin naa o 201 o Zt tt stu E pat me ridHoZ Sty agi 5 0 ot 6 ane alal o lt an oH y E 1 0 3 DAS 8131 Siy tus 3910 68 Srez a 9 0N9 0N9 vIJHPE agrs 9019 i 6 do 0AS INY 0N9 tr JIA 0AS 3ntra ant l ET aAS v3 3 3131 DAS DAS ridHre 0AS TZ ela DAS DAS z T 8131 T 7 y 5 3 Z 8 9 5 1 0 Expansion Options Troubleshooting Cannot enter the
71. TERM is invoked it transmits a special ESCape sequence to the PPC to tell it you are now running with a XX line terminal where XX is normally 24 KTERM uses the 25th line for its status display or it can be 42 49 EGA VGA with the vl option The PPC Editor reconfigures itself to the new screen size specified by KTERM However f you have powered off or rebooted the PPC without exiting KTERM the PPC will power up assuming a basic dumb 25 line terminal and the Editor will use all 25 lines KTERM being a 24 line terminal will report an attempt to place the cursor on the 25th line The solution is to exit KTERM with alt x and re invoke it while the PPC is connected Alternatively with KTERM version 1 01E or higher pressing F10 when in the Executive menu transmits the screen size to the PPC and prevents subsequent occurences of this error message The F10 method is recommended for remote modem KTERM operation because exiting KTERM might drop DTR and hang up the modem Communications line error transfer aborted Press any key Incorrect data length transfer aborted Press any key Communications CRC error transfer aborted Press any key Any of the above errors indicates loss or corruption of data during a PPC PC file transfer This should never happen unless your PC is too slow to handle the specified baud rate Try a lower baud rate 19200 or 9600 baud Invalid filename transfer aborted Press any key Invalid file extension
72. The PPC has an 1 0 expansion bus which supports the connection of custom I O subsystems The connector is a 34 way 0 1 pitch 2 row header The signals available are an 8 bit data bus several address lines and several control lines A clock is available whose frequency is 6 144MHz 12 288MHz or 18 432MHz with the standard H2 or H3 CPU speed options respectively Interrupts are possible and must be serviced using a user installed ISR The address lines A14 A15 must be decoded to 1 1 to map the card into the OxC000 0xFFFF Z180 1 0 space If any signal on the expansion connector will be driving more than 2 loads that signal should be buffered This includes the data bus It is very easy to design l O expansion cards featuring ADCs DACs FLASH memory digital 1 0 in fact just about anything The 1 0 decoding is done with simple logic or with a 16V8 GAL The circuitry can be accessed from Pascal programs using the undocumented INBC _OUTBC instructions or from C programs using all normal methods For further information on how to design your own 1 0 expansion cards please contact factory 1 0 Expansion Options 9 1 16 Bit Analog Subsystem Ii The specification of this product is subject to change Contact factory for information The following diagram shows the current version of the PPC Analog Subsystem option with the pin numbers and pin names of the 25 way D connector which the present card uses
73. This mode is not presently supported in the PPC although it could be used if the PPC was used as the basis for a custom product Step 1 Get to know the PPC You are strongly advised to acquire a general understanding of how the PPC works At least please run through the Get Started section in the PPC Manual and quickly scan the rest Step 2 Compiler Installation The Hi Tech C compiler is a DOS cross compiler which is a general purpose 280 7180 compiler and is not specific to the PPC in any way To install it follow the steps in the compiler documentation C Introduction 11 1 Keep the original disk safely and always install from a copy of it Besides this being good practice the installed copy of the compiler on the hard disk is copy protected with a scheme which ties it to some property of the hard disk If the hard disk is reformatted you will need to re install from the diskette You are right we don t like this either Unless this Hi Tech compiler is the only Hi Tech compiler which you are ever likely to use choose an installation directory name like nt180 rather than just nt This is because a version of the compiler for another CPU e g H8 300 may by default install in nt also The Hi Tech compiler disk includes C and assembler sources for the standard Hi Tech library There is no need to install these although you might as well do so unless you are short of hard disk space With very few exceptions the sta
74. WARD Procedure a is declared to be PROCEDURE b x t forward of this statement BEGIN a p Procedure a is now referenced END PROCEDURE a Actual declaration of procedure a BEGIN b q END Note that the parameters and result type of the procedure a are declared along with FORWARD and are not repeated in the main declaration of the procedure FORWARD is a Reserved Word 6 14 PPC PASCAL PROGRAM 6 0 The list of file variables in brackets Standard PASCAL is optional and does nothing in PPC PASCAL Strong TYPEing Different languages have different ways of ensuring that the user does not use an element of data in a manner which is inconsistent with its definition At one end of the scale there is machine code where no checks whatever are made on the type of variable being referenced Further up the scale comes Pascal which goes as far as allowing distinct user enumerated types At the top of the scale at present is a language like ADA in which one can define different incompatible numeric types There are basically two approaches used by Pascal implementations to strength of typing structural equivalence or name equivalence PPC PASCAL uses name equivalence for RECORDs and ARRAYs The consequences of this are clarified in the TYPE RECORD sections ef al let it suffice to give an example here say two variables are defined as follows VAR A ARRAY A C OF INTEGER B ARRAY A C OF INTEGER then you mi
75. X values of 0 5 10 15 etc Execution of a FOR loop continues until the upper limit is met or exceeded Negative step values may be used If the STEP value is omitted 10 FOR X 0 TO 100 then the step is assumed to be 1 Variable FOR parameters 10 FOR X A 3 TO B 7 STEP C 5 are supported and the expressions are evaluated only once before the loop starts so there is no huge overhead in using this method FOR loops can be nested to a depth limited only by stack space 10 FOR X 0 TO 10 20 FOR Y 0 TO 10 30 PRINT X Y X Y 40 NEXT Y 50 NEXT X Be careful to not inadvertently modify the value of the loop variable with one of the operations within the loop While this can be done it is a very poor programming practice 10 FOR X 0 TO 100 20 Y Y 1 30 IF Y 250 X 300 40 NEXT X In the above example X is potentially modified in line 30 and because its then new value 300 exceeds the upper limit 100 the loop will terminate prematurely This can produce loops which never terminate This command specifies the PPC port to which all output data will be sent until changed with another REDIR command For example the command REDIR 3 5 6 BASIC redirects all output to Port 3 INPUT This command allows direct user input of decimal numbers The command INPUT X prints X and waits for a number on an expression to be entered followed by the ENTER key The variable X will then be set to the value of the number or the expression Mul
76. a AB a 9 4 Hardware Requirements i e dee wed wacta amd Sweet eM At ie di 9 4 MAN Se oss conti goats Aa is ah Bo dh a Rt Bi 9 4 OTC a ash tet A a do owiehe ah att ok desi Oe Mas Fa Ne I brit 9 4 Sl carta dido Sle eae he Sh Bsa a ae A DAR 9 4 TFOUBIESHOOUNG 22 tes ed ark TE ote A ye cheb ond th eat abel Poe te hte archos Ak 10 1 Cannot enter the Executive oS statins Male a eae EG Ree hoe Be a 10 1 The PPC hangs on entry to Runtime Port Configuration MeNU 10 1 A program terminates for no apparent reason 2 o o 10 1 A program terminates while reading data we 10 1 A program hangs during communications a 10 2 Loopback tests hang up MePRO cara da doe dy BW ee a 10 2 ode il A tn Santen ak he Meant RN 10 2 C Introduction sass oak SRA IA AE 11 1 Step 1 Getto KNOW the PPG Govan AE Wok A oar Be ek oto de a hs 11 1 Step 2 Compiler Installation gt ooa aa a 11 1 Step 3 PPC C Software Utilities Installation 0 0 0 11 2 Step 4 C Option installation a as a e a a E a E E E A a 11 2 Stepo Reboot youn PE rars dk ter ct e A a Gee dog 0 11 2 e s matu 2 thar tat dan tae En ea weedy D are Do tami nee Alan A 11 2 Creating larger programs sar A e a e GAL aaa nad 11 3 C Referente A A E 12 1 The MEMO MAD rd a hy ee A la et han ai ka eo te 12 1 C EXENSIONS e Gert BAN attri Se de E ea yee rad cee OS ED pues A hh pao ena at 12 2 1 0 Read Write Functions ARA A fons th te ik 12 2 I O Queue Management Funct
77. a ataca botado 6 44 OPUOM AMS E ae Anat A A 6 44 O RN 6 44 COUGHS id auto a ae dr A das dea D 6 45 TOp 0 File OpliOns svc wher y o ROA RA Re Ook Ge GA re bh eS 6 45 AN EAS AA A 6 45 Option Otra ie dd Gade 50g add 6 45 ODON G dias TA ANA AA A 6 45 o A A 6 46 Program and Data liMiS 3 2 acs eck eta Gaetan e a a eR oe A 6 47 Error messages HAs at ota ced a eR Ait ah A AMAA nS tn ee Mt hor eh Sod on othe di 6 48 Compilation error Messages rra dela ar e Soo A sky ARA me 6 48 R ntim rerror MESSAGES a ot a al Whur o e aa 6 49 Reserved Words and Predefined Identifiers 00 0 ooo o o 6 50 Reserved e A A ah RL Bek ae Re Rego a aan Me esate 6 50 Special SUMO She ta aaa dde yale eae aw Sidra Reed grag 8 BANG sd ee eal 6 50 PreCetiNed IMNtIENS arr aca ys Boe atau a te eee Wea ek A Ror Ack cas Oe ora aes 6 50 Programming Examples i at ei ie eoet ded A A td ate gle eae ead a A ag tc aie Gy thie ote 6 52 Rob stireading of iNpubdala lt a Had ae ases 6 52 arde atasca emite ambito 6 52 ASGIIMUMDCIS 4 2 pta 294 da aa o bo a ed Sls aan 6 52 Multi byte binary numbers oo oo 6 53 Character translation ic a a e ahd Gas e RUA NL A oe ath a 6 53 A ceo cise ae arate dee ete Ata abet GO gh AS Beadle Meee Walle bag de Mite te AE ae a 6 54 AA IR A A A tg og heed oh 6 55 PEO Mt OE att a eee Aah A ala 6 56 Data Representation and Storage o oooooooo o ee 6 57 Data Representation a0 is aw eG ek aed
78. a tase te fee A ia anaa O 3 3 SECM POOF Ss a maana res a da ra ee A dd 28 3 3 A COMPE ONIY Te sr ae A Set Mean btn Soke hh a 3 3 5 Compile and Run aa aa 3 4 AA aie e esada Gee te tae AS aa A dde oe eg dll en ae 3 4 Gul DISHlay programi head e laa a a as do aer Diao eek A LID e e a 3 4 EZLN Mn a o a iia 3 4 A A A EN Hah ok nb ek MEN dey ch ra aAA 3 5 6 4 Delete DOTA a q aze detec ade ae Stet a AA Fuse tea nd A a ke daa 3 5 omnaDelete all serio rin do ae Ms dia Hin is ReMi ae ute Ge Eee tether hea 3 5 G0 SEL PASSWOMG cits ad katam a a Mel Buddays ats 3 5 Ge SENCYDUDFOGKAM 343 44 be da Ok ek wie ha Bara 3 5 0 07 DECKVDE PLOGKAIM sis tse bey of wh e cee ado Ge ys e ake oh ge A a hee ot nta 3 5 7 Define power up action 20 ee 3 6 e O eee E a a 3 6 AMARA or Ad a as 3 6 NOx Contig WAUNOSUCS oda Lia din ti 3 6 TOS RUIME COM nd a ai rd a Se ae ein 3 7 VOZ COMUN ais A Ai EAS de Sle et as 3 7 103 INPUENOEAUMPE Sd a a ada e lt dos E 3 8 104 Seal Pontes 2 2 ti a AA ta Fgh A ae Ale tear 3 8 105 PRIMOE COMO ita a yt en a e o Te a a eae Oh ee a 3 8 10 6 Executive Mode Port 1 config aa aaa aa a a a aaa 3 8 10 7 Set real time clock option oca ss o aoaaa a aaa 3 8 10 8 Analog Port tests A option AA A SM Li ae MO oe 3 9 A NN O ove ae Aone Sedans Bok ihn Piet Te hho peed Gath d amp At Dae Doct of amp 3 9 PREDIO ur po eat ahs Rn E Seas age See th rir watered Geode fe Boch oa ada Hac te a wT 4 1 The OOKs ORANG Editor Ao a dd atleta
79. adadcu void read ADC uncalibrated int setdac int channel int value outputto DAC calibrated int setdacu int channel int value outputto DAC uncalibrated void setadcgain int gain set ADC range void setdout unsigned int state set two TTL output lines unsigned int getdin void read two TTL input lines For a more detailed description see the similarly named functions in the PPC Pascal section The following functions provide access to the 2000 byte user accessible non volatile EEPROM area int nvwrc unsigned int addr unsigned char value write a char int nvrdc unsigned int addr read a char C Reference 12 5 int nvwrblk char src unsigned int dest unsigned int blksize write a block int nvrdblk unsigned int src char dest unsigned int blksize read a block For a more detailed description see the similarly named functions in the PPC Pascal section DES Encryption Functions The runtime code for these is present only if the PPC is fitted with the DES Option int des defkey char key char subkeybuf specify a key void des encrypt char src char dest char subkeybuf encrypt 8 bytes void des decrypt char src char dest char subkeybuf decrypt 8 bytes Further information on these functions is provided with the DES Option 12 6 C Reference Miscellaneous PPCEXTRA LIB Extra Library The following ANSI C functions a
80. agma psect strings r_ strings pragma psect data r_data pragma psect bss r_bss int main int i for i 0 i lt 10 i fprintf port1 Hello World r n loadtimer 0 500 while readtimer 0 The above program will output Hello World 10 times at 500ms intervals and then exit the main function This causes a return to the PPC Executive which provided that the Executive Mode baud rate matches the Port 1 Runtime baud rate will appear and enable you to reboot the PPC and run it all over again A copy of hello c is on the diskette The pragma directives in the last example ensure that the linker correctly locates the various data code etc sections They appear unchanged at the start of every PPC C program A ready to use makefile is provided which compiles links and locates a program hello c into a file hello bin which is suitable for immediate transfer to the PPC Type make hello bin 11 2 C Introduction and when the file has been produced with no errors use KTERM to transfer it to the PPC s internal filing system To avoid confusion with baud rates run KTERM version 1 02 or later EXE dated 1 FEB 94 or later at 9600 baud for this exercise i e without any b command line switches PPC firmware v1 06 or lower Using the Define Power Up Action menu item mark hello to execute at power up Then reboot the PPC either using the Reboot menu item or with the front panel reset Following completion of the b
81. ain SW1 pressed until the Executive menu appears Back in the Executive return to the Define Power Up Action function and select the Enter Executive mode The brief tutorial is now complete Get Started 2 3 The PPC Executive PORTA E PoRT2 W MULTI PORT COMMUNICATIONS PROCESSOR PoRT3 PORTA E The Executive is the PPC s user interface It integrates all the functions required for creation editing compilation and execution of user programs Please read through this chapter before embarking on any serious work with the PPC It contains important information which you will need in order to use the PPC effectively To enter the Executive connect a 25 line ANSI terminal configured to 9600 baud 8 bits word no parity 1 stop bit XON XOFF handshake to the PPC with the cable detailed in Serial Ports and Cables chapter as shown below TERMINAL or PC PPC EXECUTIVE PASCAL Compiler BASIC Interpreter Program Editor File Utilities amp Security ie see Serial Ports and Cables chapter Power up the PPC and a few seconds later the Executive menu will appear on the terminal Alternatively if you are using an IBM or IBM compatible PC with the KTERM EXE terminal emulator program connect your PC s COM1 port to the PPC with the cable specified in the Serial Ports and Cables chapter Power up the PPC and wait until the EXE indicator flashes This indicates that the P
82. al computer BASICs However it is adequate for simple character processing which is often the PPC s function The reduced features also make PPC BASIC run much faster than most standard BASICs Performance Like most BASICs the PPC BASIC is an interpreter and it thus runs many times slower than PPC PASCAL which is a compiled language One of the properties of an interpreted language is that a program containing many lines is likely to run slowly and although the PPC can accommodate BASIC programs hundreds of lines long such programs are likely to run too slowly to be useful for most datacomms applications For most high performance applications a compiled language is essential and PPC PASCAL should be used instead PPC PASCAL executes 20 50 times faster than PPC BASIC and also offers features such as floating point and many others Example The following simple PPC BASIC program will read characters from PPC port 3 replace every occurence of the character A 65 decimal with the character a 97 decimal and output the resulting data on PPC port 4 The comments on the right are not part of the program 10 REDIR 4 Set destination for all subsequent output to port 4 20 X WGET 3 Wait for a character on port 3 load into variable X 30 IF X 65 X 97 If the character is A change it to a 40 PRINT CHR X Output the character 50 GOTO 20 Repeat the above forever The above should be self explanatory but note one important feature which m
83. alue TRUE if there is an end of line character 13 waiting to be removed from the input port s buffer otherwise the function returns the value FALSE The default value of PORT is PORTI Transfer Functions TRUNC FUNCTION TRUNC X REAL INTEGER FUNCTION TRUNC X INTEGER INTEGER The parameter X must be of type real or integer and the value returned by TRUNC is the greatest integer less than or equal to X if X is positive or the least integer greater than or equal to X if X is negative TRUNC 1 5 returns 1 TRUNC 1 9 returns 1 ROUND FUNCTION ROUND X REAL INTEGER FUNCTION ROUND X INTEGER INTEGER X must be of type real or integer and the function returns the nearest integer to X according to standard rounding rules Examples ROUND 6 5 returns 6 ROUND 11 7 returns 12 ROUND 6 51 returns 7 ROUND 23 5 returns 24 ENTIER FUNCTION ENTIER X REAL INTEGER FUNCTION ENTIER X INTEGER INTEGER X must be of type real or integer ENTIER returns the greatest integer less than or equal to X for all X ENTIER 6 5 returns ENTIER 11 7 returns 11 ENTIER is not a Standard PASCAL function but is the equivalent of BASIC s INT It is useful when writing fast routines for many mathematical applications FUNCTION ORD X CHAR INTEGER FUNCTION ORD X INTEGER INTEGER FUNCTION ORD X any element of a set INTEGER X may be of any scalar type except real The value returned is an integer re
84. am terminates for no apparent reason 1 An execution time run time error has occured This should be indicated by the EER LED Run your program from the Executive and if PASCAL with runtime errors nof disabled If this does not reveal it check your program for places where any of the following might occur e Division by zero e Overflow during arithmetic operations Note that just simply adding 1 to an integer will cause an overflow after at most 65535 additions e Excessive memory allocation with the NEW function etc e Excessive recursion The program has crashed This is hard to achieve in BASIC or PASCAL other than by a stack overflow e g excessive subroutine nesting or by allocating too much memory with NEW Such out of memory errors cannot be disabled and will always be fatal In PASCAL runtime errors can be suppressed with the O and R compiler options however this is not a substitute for a carefully written program In BASIC runtime errors are suppressed when running in the autoexec mode but such an error causes the program to terminate and restart from the first line A program terminates while reading data 1 A 03h character CTRL C has appeared in Port 1 input data In BASIC the only way to disable break checking is to run the program in autoexec mode In PASCAL break checking is disabled with the C compiler option An invalid number has appeared in the input data when reading numbers In BASIC
85. ame way An example of array output is below var buffer array 0 99 of char fill up the array with data bwrite port2 buffer where a complete 100 byte array is output in one operation This type of output is common in PPC programming where data is often read into a buffer operated on while in the buffer and the buffer is then output Also allowed is the form bwrite port v i which writes i bytes from the variable v which would usually be an array The individual bytes of a multi byte variable are output in the order in which they are stored in memory See the Data Representation and Storage section for details of how variables are stored in PPC PASCAL As stated above only variables may be output with BWRITE and literal values such as ABCD are not supported use WRITE or WRITELN to output those If you need to output a mixture of formatted text data interspersed with binary data use a sequence of WRITE WRITELN and BWRITE invocations as required READ PROCEDURE READ PORT TEXT V1 V2 V3 Vn The procedure READ is intended for reading text i e printable ASCII data In general the statement READ PORT1 V1 V2 Vn is equivalent to BEGIN READ PORT1 V1 READ PORT1 V2 READ PORT1 Vn END where V1 V2 etc may be of type character string an array of char integer or real The port number must be specified The statement READ P V has different effects depending on the type of
86. and The CTRL U command can be issued multiple times to generate multiple identical lines which can then be edited CTRL K F This command displays the directory of all PPC files as they are currently saved in the filespace It is provided for reference only CTRL P Any key pressed after the meta key is entered into the file as its literal value This function may be used to enter control characters into the file that are normally commands or prefixes to commands e g CTRL P followed by 8 enters a CTRL H The meta key can also be used in the same way to enter control characters in the Find and Substitute strings In this case if is pressed after the meta key a character is returned that is displayed as but acts as a wild character in the find String You should never insert control characters into program files They can cause errors which can be extremely difficult to find 4 6 The Editor Prompts and Messages Prompts There are four prompts produced by the editor which normally appear on the upper status line Abandon block Sure This prompt requires a single character response It appears if the user has issued the DELETE BLOCK command and there are less than 256 bytes free If you respond Y then the block will be deleted and lost note that the block is normally saved in the block buffer and thus not lost while any other response will abort the command The prompt also appears if you have iss
87. and returns rvalue 234 val src 7 rvalue npos suc skips 1 space and returns rvalue 23 45 val src 7 ivalue npos suc returns ivalue 23 is a valid integer terminator val src 16 rvalue npos suc returns rvalue 2 56E8 val src 25 rvalue npos suc as above lowercase E accepted val src 34 ivalue npos suc returns ivalue 28 leading accepted val src 39 ivalue npos suc returns ivalue 289 number terminated by trailing non numeric characters a val src 46 ivalue npos suc returns suc FALSE because a number cannot start with a non numeric character val src 47 ivalue npos suc returns ivalue 23 The above examples do not make use of the npos return value npos greatly assists with the conversion of multiple numbers allowing VAL to pick up from where the previous VAL finished The following example reads the above array src and places the numbers into variables x1 x2 var x1 x5 x6 x7 last integer x2 x3 x4 real val src 1 x1 npos suc last npos 1 last offset of last 1 char of the first val src last x2 npos suc last last npos get the next number val src last x3 npos suc last last npos etc val src last x4 npos suc last last npos val src last x5 nmpos suc last last npos val src last x6 npos suc last last npos val src last 4 x7 npos suc this one needs to skip leading a chars Remember that npos is the offset of the last 1 ch
88. aptor are below TX CE RX EOS RIS cls DR DSR j CDO HH CDI PH 2 O Q Aa 0 N NOO For Port 1 the recommended PC PPC terminal cable below already contains the loopback connections required PC Terminal gt PPC Cable The following connections are recommended PPC 9 way PC TERMINAL 25 way 5 cup o SR0UNDESHIO o y 3 x LOREENA yg 2 gx fe KEBOMDDATA J ayy 7 RTS 8 CTS 1 4 DTR 6 DSR J 9 CDO 1 CDI This cable is designed for use with the KTERM EXE terminal emulation program Some terminals and terminal programs e g PROCOMM require a high level on their CTS and or DSR inputs pins 5 amp 6 before transmitting data this can be most easily achieved by interconnecting RTS CTS DSR pins 4 5 6 on the terminal PPC Serial Ports 8 9 he terminal must be configured for the PPC Executive Mode default 9600 baud 8 bits word no parity 1 stop it XON XOFF handshake only f your terminal supports 19200 or 38400 baud you can set the PPC to default to ose baud rates with the Executive Mode Port 1 Config menu your terminal does not support XON XOFF but does support hardware handshake connect the terminal s handshake ignal usually RTS pin 4 to the CTS input on the PPC pin 5 he above cable is not suitable for sending data from a PC with the MS DOS COPY or similar commands because the OS will not transmit unless the CTS DSR pins 5 6 on a 25 way c
89. aracter e g a digit 0 9 appears loading remaining chars into a buffer and when the end of the number is received using the VAL procedure to evaluate the number See the description of the VAL procedure for examples of this Because VAL returns a pointer to the end of each number converted multiple numbers can be converted using a simple loop To prevent VAL seeing a valid number in garbage that may exist beyond the end of the received data in the buffer the conversions should not continue beyond the data which has been actually read in The following example uses VAL to read integers from a buffer the buffer having been previously filled by reading characters until an end of line character is received It assumes that the 100 byte buffer is large enough for the longest possible line Input is on Port 2 output is on Port 3 var c char i pos lastpos value integer suc boolean buffer array 1 100 of char Fill the buffer 1 1 repeat bread port2 c read a char if c in 0 9 or c or c 0d then begin 6 52 PPC PASCAL buffer i c if numeric or space put it into the buffer i i 1 end until c 0d or i gt 100 and repeat until end of line Convert the buffer into integers pos 1 start converting at start of buffer repeat val buffer pos value lastpos suc convert number pos pos postlastpos set pos for next number if pos lt i and suc
90. aracter of the number relative to the start of the number which was supplied to VAL The above program is therefore slightly subtle In practice especially when reading mixed alpha numeric data you may need to use VAL in conjunction with a purpose written procedure which scans the input string for the items which you actually want and then invokes VAL to convert the numbers and which handles errors etc INIT initialise data PROCEDURE INIT VAR S CONSTANT CONSTANT This procedure is provided to allow easy initialisation of PASCAL variables e g arrays with a string of integer real or string constants The constants are simply placed in memory starting at the address of S The syntax diagram for a constant applies The interpretation of the constant is according to the way it is typed in mot according to the type of the variable being loaded a loads a single byte 97 dec 61 hex abcd loads four bytes 61 62 63 64 hex 97 loads a single byte 97 dec 61 hex denotes a character 61 as above 4 loads an integer 2 bytes 04 00 hex 04 is loaded in the lower address 1234 loads an integer 2 bytes 4d2 as above hex value by itself denotes an integer 04d2 as above 0 loads an integer 2 bytes 4 0 loads a real 4 bytes a real must contain a decimal point or an exponent 1234 0 loads a real 4 bytes 1234E0 as above 27 578E 23 loads a real 4 bytes 27 578e 23 as above 10000
91. are identical in their voltage levels and distance capabilities RS422 uses a driver which is always enabled and so RS422 is used only for point to point communications Like RS232 the data flow can be full duplex i e simultaneous in both directions RS485 has a tri state driver capable of being disabled when not transmitting and is used in multidrop systems The data flow is typically half duplex i e only in one direction at any one time Moreover RS485 systems are normally Master Slave systems where the Master periodically polls the Slaves and only the Master can initiate communication A Slave transmits data only in response to a poll from a Master RS485 can also be wired as 4 wire or as 2 wire A PPC RS422 485 port can operate in any of the above modes Your program can leave the driver state in its power up condition in which case it will be always enabled and you have an RS422 port If you control the driver using the software controllable RTS signal then you have effectively created a 4 wire RS485 port If you also externally interconnect TXA RXA and TXB RXB then you have a 2 wire RS485 port The following diagram shows the connection between a PPC 4 port configured for RS422 RS485 and another device PPC RS422 RS485 PERIPHERAL 5 GND A enn a Aa DATA FROM PPC A DATA FROM PPC B 29 la DATA TO PPC a ay Maes DATA TO PPC In a multidrop system with the PPC acting as the Master there can
92. are inserted if m is sufficiently large 5 e is of type Boolean Either lt e gt or lt e m gt may be used and the ASCII strings TRUE or FALSE will be output depending on the Boolean value of e using a minimum field width of 4 or 5 respectively WRITELN PROCEDURE WRITELN PORT TEXT P1 P2 P3 WRITELN is exactly identical to WRITE except it appends a CR LF character pair to the output It is useful only if you are outputting text data which is made up of CRLF terminated lines BWRITE PROCEDURE BWRITE PORT TEXT V1 V2 V3 Vn This binary write procedure is one of the PPC extensions and allows the output of arbitrary binary data It supports the output of variables only V1 Vn and no output formatting facilities are provided The port must always be specified if it is missing the error message which appears may not be obvious The following example shows how the various PPC PASCAL variables are output PPC PASCAL 6 17 var a integer b char c real d boolean a 12347 b A c 2 3728E 5 d true Given the above variables contain the above values the procedure bwrite port2 a b c d will output the following values to PORT2 in the order shown 3Bh 30h the integer 12347 decimal 303B hex 41h the byte A 41 hex BEh FOh 85h 63h the floating point value 2 3728E 5 01h the boolean value TRUE FALSE gives 00h In addition Arrays Records containing elements of any type and Sets may be output in the s
93. art of the PPC PASCAL extensions TEXT type of PORT1 PORT2 PORT3 PORT4 i e TYPE TEXT PORT1 PORT2 PORT3 PORT4 BRTYPE type of the baud rate values see list below BWTYPE type of the bits word values BW5 BW6 BW7 BW8 PRTYPE type of the parity values PNONE PEVEN PODD SBTYPE type of the stop bit values SB1 SB2 SETPORTTY PE type of the SETPORT record SETHSKTYPE type of the SETHSK record READHSKTY PE type of the READHSK record SWITCHTYPE type of SWISTAT SW2STAT SW3STAT RTCTYPE type of the SETRTC and GETRTC records The following additional predefined identifiers exist in connection with the above PORTI PORT2 PORT3 PORT4 B30 _B37H _B50 B75 B100 B110 B134H B150 B300 B600 B1200 B2000 B2400 B3600 B4800 B7200 B9600 B19200 B38400 B57600 B115200 BM5 BUG BW _BW8 PNONE PEVEN PODD SB1 SB2 6 50 PPC PASCAL The following predefined identifiers are names of record members RTS_OUT DTR OUT CDO OUT Boolean CTS IN DSR_IN CDI_IN Boolean T SEC T MIN TM HOUR TM MDAY integer TM_MON TM_YEAR TM WDAY integer SWISTAT SW2STAT SW3STAT Boolean SPPC_PORT RPPC_PORT HPPC_PORT BAUD RATE BITS WORD PARITY STOP_BIT RX_RTS H RX_DTR H RX_X_HS TX_CTS_H TX DSR H TX X HS The following is a complete list of procedures and functions PROCEDURE WRITE WRITELN BWRITE READ READLN BREAD HALT NEW MARK RELEASE RANSEED DISPOSE INIT VAL READSWI LOADTIME
94. aud rate specifications _B30 _B37H _B50 _B75 _B100 B110 B134H B150 B300 B600 B1200 B2000 B2400 7B3600 B4800 B7200 B9600 B19200 B38400 B57600 B115200 The baud rate setting has been implemented with enumerated types in this way rather than simply using integers to support baud rate values above 32767 and also to support half rates such as 37 5 baud _B37H The identifiers for the other serial parameters are shown in the comments in the above program example The record type SETPORTTYPE is also internally predefined The function SETPORT returns a non zero integer return code if any of the parameters is invalid During program debugging this return code should be tested as shown in the above example In any case Standard PASCAL dictates 6 26 PPC PASCAL 38 4 38 that a function s return code must be loaded into a variable of the appropriate type even if that variable is never tested For full details of operation of the PPC serial ports please see the PPC Serial Ports chapter Due to slight differences in the internal hardware implementations of the four PPC serial ports not all parameters are supported by all four ports See the PPC Ports chapter for a table showing which parameters are valid on which ports You must define the value of all the parameters before calling SETPORT Uninitialised parameters are undefined and will have unpredictable results If SETPORT returns a non zero return code i e an erro
95. basis i e if you write a particular address until that location is totally destroyed e g 1 000 000 times you will not have affected any other addresses in the EEPROM Because of the above whenever you write a program which writes to the EEPROM you should comment out the actual write function and insert debug e g WRITE statements which output the EEPROM addresses being written This should prove that your program is writing the EEPROM only when it should be i e not very often If your application requires the storage function in order to run at all you can debug your program with a 2000 byte array simulating the EEPROM EXECUTION TIME The write operation takes approximately 5ms 0 005 of a second per byte written The NVWRITEC function therefore takes approximately 5ms and the NVWRITEI takes about 10ms If speed is essential these functions are suitable only for writing a small number of bytes The NVWRBLK function uses a different hardware approach known as fast page mode and takes approximately 5ms per 64 bytes written a 700 byte block will therefore write in about 60ms Note that these timings are typical and your program must not rely on them SECURITY The Delete All function in the PPC Executive does not affect the 2000 byte storage area This means that the only way of deleting confidential data e g passwords stored in this area is to write a program which overwrites it There are no limits on reading the EEPROM Reads a
96. be pre configured by the installer to power up in auto answer mode However this can cause a problem because when the modem answers the incoming call it has not yet received anything from the PPC and therefore does not know the PPC s Port 1 baud rate In this situation many modems will set their DTE port to a baud rate which matches the rate of the incoming call i e an incoming call at V22bis 2400 baud will set the DTE port to 2400 baud This is fine if the PPC is also set to 2400 baud and the connection is a ways established at 2400 baud Many modems can be pre configured to a specified non varying DTE baud rate which is independent of the link rate but the commands to do this vary widely and are outside the scope of this Manual Please consult your modem manual for details Transmitting the ATSO command to the modem after each power up usually avoids the problem KTERM usage You must use KTERM version 1 1E or higher There are four cases to consider 1 Your modem supports 9600 baud DTE rate or higher but does not support a line connection at 9600 baud or higher i e it is a V22 V22bis or V32 modem only This is the most common case The commands setser coml 9600 n 8 1 kterm r ni will establish a PC modem connection at 9600 baud 2 Your modem supports more than 9600 baud DTE rate and supports a line connection at more than 9600 baud i e it is V32bis or higher modem The commands setser coml 38400 n 8 1 kterm r ni
97. begin new b allocate the buffer bread port1 b fill it up for i 1 to size buffer do do something with it begin if b i in a z then b i chr ord b i 32 end bwrite port2 b7 output it dispose b discard it end The above illustrates a typical application for dynamic memory allocation a sizeable data structure is required only temporarily but the requirement may occur in many places within a program A similar effect can be achieved by declaring the buffer within a function or procedure it will be discarded when the function or procedure exits The difference is that using NEW and DISPOSE it is possible to discard the buffer before the exit PPC PASCAL 6 25 PPC PASCAL special extensions These functions and procedures enable PASCAL programs to access the various features of the PPC They are all predefined and are ready to use SETPORT configure a serial port FUNCTION SETPORT VAR S SETPORTTYPE INTEGER This function duplicates the facilities in the Executive Run Time Serial Port Configuration menu It configures the specified port from parameters held in a record The address of the record is passed as a parameter to the function The example below sets up Port 3 to 9600 baud 8 bits word no parity 1 stop bit enables all receive handshakes and disables all transmit handshakes except XON XOFF var anyname setporttype retcode integer with anyname do begin Spp
98. boolean values held in a four member record The following example configures the output handshake on Port 3 var anyname sethsktype give the record a name retcode integer this accepts any sethsk errorcode with anyname do begin now we fill up the record as required hppc_port port3 port 1 2 3 4 rts_out true set RTS3 to high level true false dtr_out true set DTR3 to high level true false cdo out false set CD03 to low level true false end retcode sethsk anyname this actually sets up the handshakes SETHSK will return a non zero return code if any of the four parameters have invalid values The term output handshakes used here refers to the three output signals which every PPC port has regardless of whether they are actually being used as handshakes i e to control data flow For example the CDO carrier detect output is definitely not a handshake signal If either of RTS or DTR has been enabled with SETPORT or in the Executive Run Time Serial Port Configuration menu it will be controlled automatically by the PPC and any attempt to control it with SETHSK will be ignored If you want to control RTS or DTR with SETHSK that output handshake must be disabled in SETPORT or in the Executive PPC PASCAL 6 27 READHSK read handshake inputs FUNCTION READHSK VAR R READHSKTYPE INTEGER This function fills in a record with the current states of a port s input handshakes It allows the states of
99. by the PPC and controls the data flow from the TX output This signal can also be freely monitored from PASCAL or C If no connection is made to this pin it will be internally pulled up to a READY RS 232 high level state The name of this signal dates back many years and no longer means very much except when used with modems CDO Carrier Detect output This general purpose signal can be freely controlled from PASCAL or C It is intended to support the pass through of the carrier detect signal to allow a PPC to emulate a modem e g when acting as a dial up security device CDI Carrier Detect input This general purpose signal can be freely monitored from PASCAL or C It supports the connection of a modem to the PPC the state of this signal then indicates whether the modem is on line or off line With Hayes compatible modems the CD connection is not essential because they can return their status in the form of text strings but monitoring the modem s CD signal is the only unambiguous and instantaneous way of knowing the modem s status If no connection is made to this pin it will be internally pulled down to a FALSE RS 232 low level state Hardware Interface RS422 RS485 First let s straighten out a few common misconceptions RS422 and RS485 use differential signalling For each RS232 1 wire signal there are now 2 wires marked A and B Also the hardware handshakes and modem controls are not used RS422 and RS485
100. c_port port3 baud_rate b9600 bits word bw8 parity pnone stop_bit sbl rx_rts h true rx_dtr_h true rx_x_hs true tx_cts_h false tx_dsr_h false tx_x_hs true end retcode setport anyname if retcode lt gt 0 then give the record a name this accepts any setport errorcode now we fill up the record as required port 1 2 3 4 baud rate bits word _bw5 bw6 _bw7 _bw8 parity _pnone peven podd stop bits _sb1 _sb2 enable RX RTS handshake true false enable RX DTR handshake true false enable RX XON XOFF h shake true false disable TX CTS handshake true false disable TX DSR handshake true false enable TX XON XOFF h shake true false Om aaa ess this actually initialises the port optional check on setport errorcode writeln port1 Port 3 setport failed Note that as per Standard PASCAL the above WITH statement could equivalently be done as anyname sppc_port port3 anyname baud_rate _b9600 anyname bits word _bw8 anyname parity pnone anyname stop_bit _sbl anyname rx_rts h true anyname rx_dtr_h true anyname rx_x_hs true anyname tx_cts h false anyname tx_dsr_h false anyname tx_x_hs true and this is more convenient if you have previously loaded up the entire record and now wish to modify just one or two members The former WITH style produces more compact code however The following identifiers are internally predefined enumerated types for b
101. cally disables them when a program is running in autoexec mode If you do want control c to KTERM 7 7 E aj terminate your program you must specifically test for it 3 character and when detected either exit the main block or execute the HALT statement When the Executive menu appears press the F10 function key This tells the PPC the current KTERM screen size You can now perform any Executive function except changing the Port 1 or Executive Mode baud rates When modifications etc are finished the PPC program which should still be marked autoexec can be restarted by selecting the Reboot function on the main menu If you have uploaded new programs to the PPC the autoexec marker could be pointing to a different program from its previous position Check this Dont exit KTERM while the modem is online It might drop the PC s DTR which would then hang up the modem Shelling out to DOS from KTERM alt z is OK however Finally disconnect the modem link by hanging up your modem This can be done from your modem s front panel or by powering it down or by typing the command while still in KTERM Each of the above characters represents a 1 second at least delay it is not actually typed The three characters must be typed in rapid succession 7 8 KTERM KTERM Troubleshooting Executive menu does not appear at all 1 Press the ESC key several times 2 Exit KTERM with alt x and re
102. cated with NEW The run time stack s used to implement function and procedure call and returns and holds all local variables variables declared within functions and procedures In summary the sum of code plus static data must not exceed approximately 30 000 bytes Programs which violate this will not be executed However if you periodically compile your program as it is being developed you will have a good idea how much space is left at any point PPC PASCAL 6 47 Error messages Compilation error messages An arrow indicates the approximate position of the error within the program The actual error location is usually just before the arrow and if a Pascal statement is not entirely resident on a single line the error could be on a line preceeding the arrow position Most of the error messages are self explanatory Number is too large Semi colon or END expected before here Undeclared identifier Identifier expected not in constant declarations gt expected This identifier can t begin a statement expected expected Wrong type combination gt expected Factor expected Constant expected Identifier is not a constant THEN expected D0 expected TO or DOWNTO expected expected Can t write this type of expression OF expected comma expected colon expected PROGRAW expected Variable expected as parameter BEGIN expected Variable expected in READ Cannot
103. ccess the serial port on which KTERM is running Examples include communications programs of all types KTERM command line options The following command line options displayed with KTERM H are supported by KTERM COMx Specifies the PC serial port to which the PPC is connected Default is COM1 Only COM1 and COM2 are supported B Specifies the PC serial port baud rate The default is 9600 baud Only 9600 19200 and 38400 baud are supported 38400 baud is highly desirable when editing larger programs but may not work reliably on slower PCs Specifying a baud rate value in KTERM causes KTERM to send to the PPC a special ESCape sequence which instructs the PPC to re configure its serial port to that baud rate When you exit KTERM with alt x it will change the PPC back to 9600 baud Therefore the PPC should always be set in the Executive Mode Port 1 Config menu to 9600 baud regardless of which baud rate KTERM is running at e KTERM always fully configures the serial port to its requirements and restores the original configuration upon exit There is no need for e g a preceeding MODE or SETSER command INL Selects large screen video mode 43 lines on EGA and 50 lines on VGA displays The default is 25 lines which gives the standard KTERM display of 24 lines plus the bottom status line M Forces a monochrome display Can produce a more readable display on portables with LCD or plasma displays The default is a display which matches yo
104. ceeded This will usually manifest itself as corrupted data or blown up interface chips If in doubt make sure the GND connection is present or use a port isolator In multidrop systems one sometimes needs pullup pulldown resistors to ensure that the bus is in the proper space state when no device is driving it The PPC does not have these resistors built in Some devices have them but connected the wrong way round causing all receivers to receive long break levels whenever the bus is not driven This manifests itself as garbage received before each message 10 2 Troubleshooting C Introduction This chapter is a quick get started guide to the PPC C programming option With the C option installed the PPC retains all its functionality as described elsewhere in this Manual Both Pascal and Basic remain available The C option has been implemented in a way which makes programming very straightforward and apart from the obvious necessity for you to know some C much easier than C programming on other hardware devices The compiler is a full ANSI C compiler which generates state of the art highly optimised code It is not a tiny C or other C with reduced functionality Many PPC specific comms and other extensions have been added How was the C option implemented on the PPC A standard PPC can handle files of type Pascal and Basic With the C option support for type Binary has been added You simply compile your
105. compare expressions of this type Type INTEGER or REAL expected Can t read this type of variable Identifier is not a type Exponent expected in real number Scalar expression expected Null strings not allowed use CHR 0 T expected expected Array index type must be scalar gt expected T or expected in ARRAY decl Lowerbound upperbound Set too large 256 elements Function result must be type identifier gt or expected in set gt or or F expected in set Parameter type must be type identifier Null set not allowed here Scalar including real expected Scalar not real expected Sets incompatible gt and lt can t be used with sets Hex digit expected Array too large 64K END or expected in RECORD defn Field identifier expected 6 48 PPC PASCAL Variable expected after WITH Variable in WITH must be RECORD type No associated WITH statement Unsigned integer expected after LABEL Unsigned integer expected after GOTO Label at wrong level Undeclared label Can only use equality tests on pointers Bad string constant Too many s Only e m h valid Strings can t have EOLNs Parameter must be a POINTER variable Variable parameter required BREAD BWRITE supports variables only SIZE takes variable or type identifier Symbol Table Full TOO MUCH CODE or TOO MUCH DATA Runtime error messages When a runtime error is detected then one of the following messages will be d
106. compiler option 3 KTERM has a 1024 byte receive buffer This means that data can be appearing on the screen for several seconds after the PPC has stopped transmitting KTERM Error Messages Video subsystem does not support large screen mode You have used the vi option but your display is not EGA or VGA Specified COM channel is already in use Before configuring its serial port KTERM has determined that an existing program has possibly set up its own interrupt vectors for that port COM1 if no port has been specified 1 Check the contents of your AUTOEXEC BAT and CONFIG SYS files and remove any programs likely to be accessing the serial port used by KTERM Likely candidates are mouse or digitiser drivers some of which grab every serial port present in an attempt to detect if a mouse digitiser is attached and do not release them afterwards 2 If you are sure that no program is meant to be using the port use the ov option 3 lf your CONFIG SYS file contains a STACKS A B command where A or B is non zero or you are running DOS version 5 or higher then use the ov option Kterm is already active type exit to return You have shelled out of KTERM with alt z and then tried to invoke another copy of KTERM This is not supported Type EXIT to return to the original copy of KTERM KTERM 7 9 Invalid cursor position detected Exit KTERM and reenter This error should occur only while in the PPC Editor and is more subtle when K
107. ct 1 0 expansion bus and power connections RS485 driver control For an RS422 port leave the driver permanently enabled by not changing RTS For an RS485 port to enable the RS485 driver set RTS to a 1 and vice versa To control RTS use the SETHSK or setporthsk in Pascal or C respectively The DTR and CDO signals are irrelevant The PPC Utilities disk contains example RS422 485 programs When turning off the driver make sure the entire message has been transmitted first The function OPQCOUNT is ideal for this and is most accurate on ports 3 4 where its returned value includes the exact contents of the UART transmit circuitry Therefore ports best suited to high speed RS485 use are ports 3 and 4 l Ports 1 or 2 are used for RS485 a different procedure is used to determine the correct driver turn off time see the OPQCOUNT function description Remember also that on a 2 wire RS485 system you will also be receiving your own transmission and may need to discard it by issuing an IPQCLEAR after the message has been transmitted This can however be useful as the reception of the last character of your transmitted message can be used to immediately turn off the driver 8 4 PPC Serial Ports 1 0 Queues Each PPC port contains two queues a transmit TX queue and a receive RX queue TRANSMIT QUEUE 64 BYTES TX USER PROGRAM l RECEIVE QUEUE 255 BYT
108. cter on Port 1 and load it into C 30 IF C 66 C 67 if the char is B then make it C 40 PRINT CHR C output it to the default port Port 1 50 GOTO 10 and repeat forever Run the program by typing RUN lt 1 The program starts with the word READY and expects some data If you press various keys on the keyboard you will see that they are echoed unchanged except that the letter B is changed to C To terminate the program press CTRL C press C while holding down the CTRL key You may have to press it more than once Save the program in the PPC s filespace under the name BTOCB with the command SAVE BTOCB Upper lowercase is irrelevant Confirm that it has been saved with the command DIR H The program is still in memory and can be RUN again if desired Finally exit BASIC with BYE y Step 6 PASCAL and the Editor PASCAL programs cannot be interactively typed in as we did with BASIC Instead an empty program is created and the PPC editor is used to type in the text Highlight the Create Program item and press At the program name prompt type BTOCP H upper lowercase is irrelevant and when the language selector appears highlight the Pascal selection and press When the program has been successfully created press ESC to exit to the Executive main menu In the program directory on the right you will see the newly created program BTOCP with a Pascal language attribute a size of zero bytes and a gt marker disp
109. ctory then use the N keys to highlight the desired program which is finally selected with the ENTER key The selected program is now marked with a gt marker Similarly to select a particular Executive function use the key to place the highlighted bar into the function selector then use the TL keys to highlight the desired function which is finally invoked with I the ENTER key When you have descended into a sub menu you can return to the previous menu with ESC The ESC key can be used to exit from most Executive functions Do not press CTRL S while you are in any of the Executive functions these include the editor the compiler BASIC or a PASCAL program running from Compile amp Run CTRL S is an XOFF which will stop all output to the terminal until a CTRL Q XON is pressed The Program Directory This shows all programs currently stored in the filing system Up to 20 programs may be stored The terms programs and files are used interchangeably in this Manual In the PPC every file should be a BASIC or PASCAL program otherwise it serves no purpose All programs are stored in a non volatile EEPROM device Non volatile means that the data is not lost when power is disconnected just like a e g a hard disk An EEPROM device is highly secure highly reliable and does not require any batteries either Do not disconnect power to the PPC when file operations are taking place Doing so will probably result in loss of da
110. d system and is largely a hang over from the origins of RS232 back in the 1960s int brkchk int port return 1 if break detected and clear the break detect flag int brkout int port unsigned int duration senda break length in ms brkout uses PPC timer 7 internally The PPC tests the port 3 4 UARTs for a break condition from within a 1kHz interrupt and brkchk may therefore fail to report an incoming break level if it lasts lt 1ms Timing Functions The PPC contains eight timers numbered 0 7 each of which is decremented to zero under interrupt at 1kHz Each timer can be loaded with a value up to 65535ms int loadtimer int timernum unsigned int timervalue unsigned int readtimer int timernum loadtimer returns 1 if an invalid timer is specified 0 otherwise The above functions do not require the RTC option Real Time Clock Functions The PPC optionally contains a lithium battery backed real time clock This can be set and read with the two following functions int getrtc struct tm anyname read RTC into tm int setrtc struct tm anyname setRTC from tm Both functions use the standard ANSI C structure tm which is defined in ppclib h Some members of tm e g the daylight saving flag are not implemented Legal year values are 1950 2049 represented years since 1900 see tm as 50 149 Note that there is no PPC function which returns date time in the form of a long int represent
111. d not normally need to know this NVREADI read an integer FUNCTION NVREADI EEPROMADDR INTEGER VAR I INTEGER INTEGER 6 42 This function is the opposite of the NVWRITEI function above lt reads two bytes representing an integer from the EEPROM Valid addresses are 0 1998 decimal NVWRBLK write a block FUNCTION NVWRBLK SOURCE EEPROMADDR BYTES INTEGER INTEGER This function writes a block up to 2000 bytes in length from any PASCAL data structure e g from an array to the EEPROM in a single operation given a memory source address and an EEPROM destination address The same functionality could of course be achieved with a sequence of NVWRITEC calls but NVWRBLK is much faster for large blocks of data because it uses a different underlying hardware mechanism to access the EEPROM The execution time varies according to several factors but is around 12ms max 6ms typ for every 64 bytes in the block being written a 640 byte block will therefore write in 120ms max 60ms typ The following conditions will return an errorcode 1 1 An overlapping block Valid EEPROM addresses are 0 1999 but the entire block being written must be written inside the 2000 byte area Thus when writing e g a 500 byte block the valid starting EEPROM address range is 0 1499 the block will be written to addresses 1499 1999 inclusive 2 Starting EEPROM address out of the 0 1999 range 3 A source address which starts below the PASCAL
112. d rate must match the Port 1 Runtime baud rate Modem configuration No special configuration is required in most cases Most modern modems are auto baud rate sensing at their DTE port and the local PC attached modem will usually auto configure when it receives the first data from KTERM Most modems do their auto baud rate detection from the A of the AT command Make sure that the first thing you send to the modem is something starting with AT When KTERM is started it always transmits a special initialisation sequence This is intended for the PPC but when KTERM is used to communicate with a modem the modem will treat this as garbage not least because the sequence does not start with the AT command Therefore you need to transmit the AT command to the modem at the proper baud rate to which you wish to set the modem before starting KTERM The simplest way to do this is with a batch file containing a MODE or SETSER command followed by COPY FILE COM where file contains an AT command followed by KTERM The remote PPC attached modem must be configured to auto answer With Hayes compatible modems this is usually done with the command 7 6 KTERM ATSO 1 lt CR gt where the 1 specifies the number of rings to wait before answering Your PPC based program must transmit the above string to the modem with the suggested Pascal statement writeln portl ATSO 1 Alternatively the modem can
113. d to produce the final bin file You will also need a make utility to run the supplied makefile Virtually any such utility including those supplied with Borland or Microsoft languages can be used The standard protected mode make is preferred because it leaves more memory for the compiler Current versions of the Hi Tech compiler are 386 only protected mode versions These work in the same way as the old real mode version Not all features of the Hi Tech compiler are supported with the PPC The compiler includes an IDE integrated development environment However because of the ease with which a makefile based system can be set up and because many programmers prefer to use their favourite editor anyway the use of the IDE to achieve the various required compiler and linker operations is not documented here Also the simpler makefile approach may be preferred for projects which may need to be maintained far into the future The Hi Tech compiler kit includes a source level debugger called Lucifer At present this is not supported It is much less necessary than would be the case with other targets because the PPC s interrupt driven background transmit makes it very easy to insert debug statements into a program without slowing its execution in a way which would make the results meaningless The compiler also supports large model programs These use code banking to enable generation of programs with gt 64k of code
114. dition 1985 Pitman ISBN 0 273 02155 9 A book which illustrates Pascal through programs which solve common electrical and electronic problems A good readable introduction to Pascal but not recommended for general use unless you are into electronics W Findlay Pascal An Introduction to Methodical Programming D A Watt 3rd Edition 1985 Pitman ISBN 0 273 02188 5 Boris Allan Introducing Pascal 1st Edition 1984 Granada ISBN 0 246 12323 0 Reference Books N Wirth Pascal User Manual and Report K Jensen 2nd Edition 1975 Springer Verlag ISBN 0 387 90144 2 The Standard Pascal reference Written before interactive systems were commonplace and in the area of real time 1 0 very dated J Tiberghien The Pascal Handbook 1st Edition 1981 Sybex ISBN 0 89588 053 9 PPC PASCAL 6 59 KTERM Terminal Emulator What is KTERM KTERM EXE is a ANSI compatible terminal emulation program which allows users of IBM and IBM compatible PCs to access the PPC Executive Why use KTERM All PPC features are accessible with just a dumb ANSI compatible terminal In addition if you wish to use your IBM or IBM compatible PC as the terminal most of the various commercially available terminal emulation programs will work However the supplied KTERM EXE terminal emulator offers special features not available on any other terminal emulation program O KTERM supports file transfer between the PPC and your PC This is extremely useful in t
115. ds to operate the various signals as modem control lines in which case you may need to directly access DTR CDI and possibly CDO or if you are doing RS485 communications in which case you will be controlling the RTS signal The first of the following two functions enables your C program to directly control the three handshake output signals and the second allows the present states of the three handshake input signals to be read back Similarly to setportcfg getportcfg above these operations are done via structures sph_t and gph_t which are defined in ppclib h int setporthsk struct sph_t anyname configure handshakes from sph_t int getporthsk struct gph t anyname fills in gph_t If either of RTS or DTR has been enabled with setportcfg or in the Executive Run Time Serial Port Configuration menu it will be controlled automatically by the PPC and any attempt to control it with setporthsk will be ignored If you want to control RTS or DTR with setporthsk that output handshake must be disabled with setportcfg or in the Executive Break Sequences Ports 3 4 are capable of detecting and generating an RS232 break level This is in effect an over length start bit and can be used to indicate to the receiving end a condition which could not be represented simply by sending a normal message Unless you must use break generation for a very good reason avoid it It is rarely necessary in a properly designe
116. e If s is selected then at the beginning of each procedure and function call a check is made to see if the stack will probably overflow in this block If the runtime stack overflows the dynamic variable heap or the program then the message Out of RAM at PC XXXX is displayed and execution aborted Naturally this is not foolproof if a procedure has a large amount of stack usage within itself then the program may crash Alternatively if a function contains very little stack usage while utilising recursion then it is possible for the function to be halted unnecessarily If S is selected then no stack checks are performed this improves execution speed Default is S Option A Controls whether checks are made to ensure that array indices are within the bounds specified in the array s declaration If A is selected and an array index is too high or too low then the message Index too high or Index too low will be displayed and the program execution halted If A is selected then no such checks are made this improves execution speed Default is At Option When using 16 bit 2 s complement integer arithmetic overflow occurs when performing a gt lt gt or lt operation if the arguments differ by more than MAXINT 32767 If this occurs then the result of the comparison will be incorrect This will not normally present any difficulties however should you wish to compare such numbers the use of I ensures that the results of
117. e PPC just like any other It cannot however be edited with the PPC editor KPACK EXE is documented in the file KPACK DOC and is supplied on the diskette 6 56 PPC PASCAL Data Representation and Storage Data Representation The following discussion details how data is represented internally by PPC PASCAL Read this chapter only if you are reading or writing PPC PASCAL variables other than characters with the BREAD or BWRITE procedures or performing type conversions with the procedure RECAST The information here is not required to program in PASCAL and could even be confusing Integers Integers occupy 2 bytes of storage each in 2 s complement form Examples 1 0001 256 0100 256 FFOO The less significant byte is stored at the lower memory address When reading integers with BREAD the less significant byte is expected first When writing integers with BWRITE the less significant byte is output first Characters Booleans and other Scalars These occupy 1 byte of storage each in pure unsigned binary Characters 8 bit extended ASCII is used El 45 ps 5B Note that on Port 1 characters above EFh 239 dec cannot be entered from a terminal when the PPC is in Executive Mode because those codes are used internally Booleans TRUE 01 FALSE 00 Reals The real number is stored in a mantissa exponent form in four bytes one byte for the exponent and three bytes for the mantissa The way in
118. e an inverse mono KTERM ov use COM1 9600 baud override interrupt vector c In general you should use the highest baud rate possible 38400 baud because th updates However slow PCs will lose serial receive data at such high baud rates and thi corruption or persistent error messages during file transfers If you intend to use KTERM as a general purpose terminal emulator in non PPC app e The file KTERM LOG is reset splay this is the recommended mode for high performance on VGA isplay display hecking is will give the fastest screen s will manifest itself as screen ications note that it does not support a the ANSI commands It supports only a limited set of commands which are actually used by the PPC It also transmits special commands when it starts up 7 4 KTERM KTERM under Windows 3 x Windows 95 Windows NT 4 KTERM runs under the above either full screen or in a DOS box All functions including file transfer are supported except sometimes the ctrl z DOS shell command The supplied KTERM PIF and KTERM ICO files are required and must be copied to your hard disk a suggested location is the WINDOWS directory Then select the File option select New and create a new program item called KTERM with the appropriate path pointing to where KTERM EXE is stored This will create the KTERM icon which appears in the top left corner of the screen below Double clicking on the KTERM icon invokes KTERM as sho
119. e ek tea a e oda Md S aa e cca Aha 8 6 TA HandshakeS ci mark dadas ds ara ara rues Ade due uch ale 8 6 RX Handshakes 20 dara at tat a rl e d nde arta amp Ale aa 8 6 Binary Data Handshakihg xo ccoo ai taa al a Al ee td ate io 8 6 Modem Control os adds Aa de lod cite y a o a 8 7 UA O fel lac NAS AS Re ce a A Maa 8 8 Executive Mode configuration es 8 8 GANGS ste to dds e Ae eg der te ow es ay BAN la de dull aad odes a Me eae eis he A 8 9 AA Fe ele one ie a gh we As Sa a he oR ae ee he Bae dee aoe ws 8 9 PRG ebOpU bark AdaDtOrS ce o an ae Met ohh AS ew et Pek tae oh Ae ls E Mabey 8 9 PC Terminal e gt PPC Cable a Be BAAS She be a eM ee AE cd 8 9 POS PRC Cane ee iD bea duh eo pie tat ot Ss Ra eae oa oa eee eaters 8 10 PPC printer plotter cable o oa a a ooo 8 10 PPC CalComp plotter cable DTE OSEA eekly ar gle op Sets 8 11 EXAMS OM ODOM 30 2 acd Pek toe et anaa Bete eo delta lla SE a 9 1 16 Bit AnalOg SUDSYSIEM a isise dl Seat A to Baha Anh dak AM a 9 2 Facilities and Operating Modes 2 o o 9 2 Hardware Requirements o 9 3 Accuracy and Performance 3 26 8 wea ae ed ke ee ee ee 9 3 E Ble etre ook amp Bet Soe ih tt vi ah OM Bete del ot Gan eo bet oe ee edt 9 3 Protection cea aen Goats ich cal Sh nah A Me dine Ma Mae hi Oe ease ey 9 3 Aaa Say lore Milt hie ral al Picky Moncey yen dat ad Dew Sopa hod 9 3 DGI Digital IS AEG se aus ofA Ax ere ahh IA is Ao tee SE oh a a
120. e isolated RS232 RS422 485 20mA interface converter with intelligent data processing options Three standard product versions cover most industrial interface and protocol conversion applications from a simple interface converter to a fully user programmable unit A MODBUS RTU comms library is available for rapid development of MODBUS to custom protocol converters using ANSI C Features include Auto Driver Enable an Addressable Adapter Mode for multidropping non addressable devices baud rates 30 115200 baud The KD485 is 7 35V DC powered C programs are generally very portable between the PPC and the KD485 We welcome enquiries for custom products We have delivered many custom solutions generally based on the PPC or the KD485 SYSTEMS KK Systems Ltd Tates London Road T 44 1273 857185 Pyecombe Brighton fax 44 1273 857186 BN45 7ED e mail info kksystems com Great Britain www www kksystems com Any questions or suggestions are welcome
121. e main Executive menu select the Create program function and enter the name TEST1 with language PASCAL This creates an empty program which will appear in the directory with size 0 Return to the main menu with ESC You will notice the gt marker against the newly created program Now enter the editor by selecting the Edit program item and type in the program text below Note that the indents are not important but they do make programs more readable Use the TAB key to achieve the indents program testl var i integer begin 1 0 repeat write portl ii 1 1 1 until i gt 5 end You may have noticed the program contains a deliberate mistake Save the program and exit the editor with ctrl k x and select the Compile only function This will compile the program and will display the following compilation listing and an error message 8900 1 program testl 8900 2 var i integer 8906 3 begin 8909 4 1 0 890F 5 repeat 890F 6 write portl ii ERROR a Undeclared identifier ESC gt EXECUTIVE C gt continue compilation E gt Editor The error was that you used an identifier ii instead of i Note that the compiler has marked a point in the program after the exact error location this is often the case To correct the error re enter the editor by pressing E Back in the editor the cursor is automatically placed for you at the point in the program where the error was spotted To correct it in this case move the cursor over one
122. e of Contents RRG VEB yin tao AAA do Se a E A S 1 1 Wise a cd wes ta a Vas 1 1 The YRrONt Panels cd DAA A A A A tai dd 1 2 SW2FSW3 PRU Reset isn uk E rd dea E ee Aah dl td toe Pak ee a 1 2 SW1 Entry into the Executive ee 1 2 ED IMGICALORS o bac arene eet ep Pee A i den a a ah AD A NO 1 2 MA ik mete od diese Ge A Ri Geek Ate Ah ab ee Weta de ok eA Y 1 3 PRO oe dad deeds Moola Sa See ON te A 1 3 Se ee A eee ee ee ee ee O ce ee ee ee ee ee ee A 1 3 O ub Snead na ioe tans oe cee A each ae Be Rede 2 AA aR 2 1 Step 1 Software Installation o a aaa a ee 2 1 Step 2 SCOMECIONS man stl deme a a dm n ma Ae eaae ar a lr a 2 1 Step 3 Enter the Executive 0 aa 2 1 Step 4 Executive operations ee 2 1 A A Se aed se Bde A My ne Ae ad incl ta 2 2 Step Of PASCAL Ne Ed vce datar oe dale Rye pa he Mab ati Ds 2 2 SIG Dal A A ON cet lt i Ri tte lott cp Pie Gore Pas ae E Ni Geb Sn APD rane hae ac blag 2 3 Md EXGCUIVE lt p 20 Pace 2p wicca E IE aT eh Ne ae De se oes oa 3 1 PPC Exgc tive Fundamentals zo ot oc ied cx os ot e aa ks A A nerd Ske tl ate tS a 3 2 BaSICcPIIMGIDIGS Snas nA mia deen Gente AN ky Mes Ava te by DA 3 2 The Program DIRECTORY e NEA eter tok oe ta Behind Se ton atc a Le Bue a tah MGS a A 3 2 Program Name RUES sidra ta it tnt cage strat sagt ecient tet get ity af ed a onto 3 2 PPC Executive functions and facilities comedo Mae o Hevea eed 3 3 delnteractive Basi tie mrica monone AN 33 2y Greate PHOGKAM
123. e to observe the above will result in the XON XOFF codes 11 and 13 hex to disappear from your data This may not be immediately apparent and will certainly not be apparent if you are testing your system with printable data only 8 6 PPC Serial Ports aj aj Modem Control The following information applies to modern Hayes compatible asynchronous modems with internal data buffering It may not apply to old modems or special purpose modems The data flow from the PPC to the modem is handshaked by the modem s CTS signal The data flow from the modem to the PPC is handshaked by the PPC s RTS signal This is equivalent to a standard PC modem connection with hardware handshakes XON XOFF handshaking should be avoided because it prevents the transfer of 8 bit binary data The following diagram illustrates the usual connections Note that the PPC pin outs are for its 9 way D connectors whereas the modem pin outs are for the standard 25 way modem D connector PPC 9 way MODEM 25 way 5 GND GROUND GND 147 Sa TX DATA x 2 9 RX RX DATA RX 3 HANDSHAKE RTS 4 i HANDSHAKE CTS 5 TE ON ds 101 MODEM CONTROL DTR 20 6 DSR DSR 6 9 CDO de he CARRIER DETECT CD 8 The PPC port should be configured with the following handshakes RX handshakes RTS DTR XON XOFF TX handshakes CTS DSR XON XOFF ON OFF OFF ON OFF OFF The RTS signal is controlled automatically by the PPC It is normally HIGH unless the modem is sending data w
124. ee hap sp ee Rae dene 6 16 WRITE aradi oh doi Ue ante es ede nid se ido iene accel Maan A She eara Get tee 6 16 A ea whe ates ahr ei eine ae Wanted BB AL cece at Ale ae oe Asai 6 17 VINE 224 ran Ase ioe dr ds Dk e add a 6 17 READ A A A E 6 18 READLN tai feet of ok et dl inde a Pad Si Mod lada ta Saale 6 19 BREADS A A E ith de te ANE A Ae a NS Be ARN 6 19 Ele Handling FUNCHONS oee tii e Mota a eee Ae a ta a td 6 20 ON G Ni Sar be AS 6 20 Trarister FUNCIONS A iy 4 4 abla de Ais goalie E foro Hotes 1G Sod ake hap Gul tye it Ae ais 6 20 Ua Soh gate te ete te Meee hehe ee Ratton ke aoe a whan Se Deans Weal ohn ea 6 20 Ps areca 2 pak ae Se E 6 20 ENTER 2 12 2 2 bd iu Bat Ar pda er alee Bee ara eas ied A 6 20 ORD cat site oh Bh te a ote A ees AS Ie HPCC EE RD wus PVE a 0 6 20 CHR aS Se ese ch ath cen Seah ak une SMe Bay devas Pu tg Ge is OF ALT Se hana aD Soya neh cil 6 20 Arithime tiCcFUnctiOnSs y score are oe tad ie ee A ee So Polo ete i a eal 6 21 PB cage shes Mle A CR E A a a 6 2 SORS aii a r A A AA 6 2 A A E Li aA i AN a aa a Ea aN 6 2 FRAG tec o cane e ta a ad E E ro to 6 2 A O E ANN fe ot tanh 6 2 A AN 6 2 TAN A E ERANA E O 6 2 ARGTAN Lat o Bok Ate dele A e de O ad DU 6 21 EX Pirm te ES o gee A oe Sp id ojala odes on Ce me oe 6 2 AA NI AI oe AS AN AIN 6 22 A HO te Bin gop cate A A AO 6 22 RANSEEDN amangan ra rada pda dd ea 6 22 RANDOM Lira do bar elo pd ao ele Se 6 22 SUCCO dd doi O OR AS S 6 22 A A AE AI E 6 22 O O 6 22
125. elf makes the compiler accept upper and lower case letters as being different so that the identifiers Loop LOOP LooP are 3 separate identifiers without the U option these 3 would be converted to one identifier LOOP by the compiler The default is no U option i e upper lowercase equivalence This allows all of the PASCAL program to be entered in lowercase except literal constants such as ABCD and A which are always case sensitive and makes it more readable When using U you must make sure that all reserved words and predefined identifiers of the latter there are many are in UPPERCASE 6 46 PPC PASCAL Program and Data limits After each successful compilation in the Compile Only mode the compiler displays figures which show how much of the available memory has been used by the program This section describes the meaning of those figures The information is in the form RAM usage decimal code AAAA BBBB XX statics CCCC DDDD YY where AAAA is the number of bytes of code generated BBBB is the total amount of space available for code approx 26 000 bytes cccc is the number of bytes of static data allocated during compilation DDDD is the total amount of space available for static data approx 30 000 bytes XX is simply AAAA 100 BBBB YY is simply CCCC 100 DDDD The slight complication is that code and data share the same 30 000 byte approx block of memory Therefore the space for code is reduced by the am
126. en insert the block at the cursor position If there is enough space the block will be retained in the buffer but the less space there is the longer the command will take CTRL K C Copy the currently marked block from the text to the cursor position CTRL K Y Delete the currently marked block from the text and place in the buffer The less space there is the longer this command will take If the amount of free space is very small less than 256 you are asked whether to abandon the block If you press Y then the block will be deleted from the text and not placed in the block buffer If you don t want to lose the block then N should be pressed CTRL K P Insert at the cursor the block currently in the block buffer The block remains in the buffer if there is sufficient space The Editor 4 3 aj aj Quick Cursor Movement Goto line Goto start end of block Remember position Return to position Go to start of file Go to end of file Find and Substitute Find first Find next Substitute next Substitute all CTRL 0 You are prompted for a line number BACKSPACE operates as expected and after the cursor is placed at the start of the line given CTRL QB CTRL Q K Move the cursor to the start end block marker CTRL K 0 zero The current cursor position is stored The marker is lost if the line in which it lies is subsequently edited CTRL Q 0 zero The cursor is positioned at the previously marked pos
127. erations including the results of comparisons The result is always TRUE or FALSE TEXT This type is used for the various predefined identifiers used in PPC port initialisation and control procedures See the PPC PASCAL Extensions section for details Variables There are no predefined variables in PPC PASCAL PROCEDURES AND FUNCTIONS File Handling Procedures WRITE PROCEDURE WRITE PORT TEXT P1 P2 P3 The procedure WRITE is intended for outputting text data The destination must always be specified It can be a port name or the name of a suitable array e g var buffer array 0 99 of char num integer write buffer all this will be placed into the buffer num write portl all this will go to Port 1 num The above facility for writing to memory instead of to a port is available on WRITE WRITELN but not BWRITE procedures It was not supported by early versions of PPC Pascal When writing to memory there is no checking for overflow of the destination buffer The WRITE parameters P1 P2 Pn can have one of the following forms lt e gt or lt e m gt or lt e m n gt or lt e m H gt where e m and n are expressions and H is a literal constant We have 5 cases to examine 1 e is of type INTEGER and either lt e gt or lt e m gt is used The value of the integer expression e is converted to a character string with a trailing space The length of the string may be increased with leading spaces by the use of m
128. eter The following example shows a procedure for positioning the cursor on an ANSI terminal and its invocation with the x y values of 75 23 procedure cursorpos p text x y integer begin write p 1b y 1 3 x 1 H 1 disables trailing spaces end cursorpos port2 75 23 Note that on the two port PPC version PPC 2 the files PORT3 and PORT4 are not defined Contrary to Standard PASCAL there are no predefined INPUT and OUTPUT files All file 1 0 statements must specify a port WRITE and WRITELN are the only exceptions and they assume PORT1 as the default If you execute a READ BREAD READLN statement and there is no input data the program will wait until the expected number of bytes arrives it other words the program might appear to hang In most cases this will not matter since in the absence of input data the program may not have anything to do anyway but if desired a hang can be prevented by testing the 1 0 buffer status with functions provided The destination e g port or an address is mandatory in write writeln and bwrite statements This is to allow the alternative construct which redirects output to an array of char and which is extremely useful The predefined type TEXT in PPC PASCAL has no connection with files of type TEXT etc in Standard PASCAL As the type TEXT is a enumerated type with the predefined constants PORT1 PORT2 PORT3 PORT4 you can use items of type TEXT in record definitions etc s
129. ew program s name followed by J The actual copy operation can take up to 10 seconds 6 4 Delete program When this function is selected with J you are prompted to confirm with Y The actual delete operation can take up to 10 seconds The Executive will not permit a delete if the Power Up Action is set to autoexec a program this prevents accidents such as deleting the autoexec program The deleted program cannot be un deleted and cannot be recovered Don t rely on this for security though 6 5 Delete all When this function is selected with J you are prompted to confirm with Y The operation can take up to 10 seconds This function does not affect any part of the PPC configuration and it does not affect the 2000 byte Pascal accessible nonvolatile storage area It does however reset the Power up Action setting to the Enter Executive state to prevent the possible power up execution of a nonexistent program All programs stored in the PPC are irreversibly deleted and overwritten with zeroes 6 6 Set password When this function is selected with you are prompted to enter a password which will be used for all subsequent Encrypt and Decrypt operations The password does not currently serve any other purpose It is not permanently stored and is deleted when the Executive terminates e g at power down or when the Reboot function is invoked The password must be 8 16 characters in length and is case sensitive Any charac
130. f on off on off on off TX CTS h shake always on t always on Tt on off on off TX DSR h shake on off on off on off on off TX XON XOFF h shake on off on off on off on off When configuring from the Executive Port Config function the Executive ensures that invalid combinations cannot be set When configuring from a PASCAL program the PASCAL function SETPORT returns a non zero errorcode if an invalid combination is detected the only exceptions are marked in the above table with t and these do not generate errors in SETPORT Baud rates marked with are not supported in the H2 2x higher speed version of the PPC Executive Mode configuration When the PPC is in its Executive mode Port 1 is automatically configured to work correctly with a terminal or with KTERM This Executive configuration is most likely different from the runtime configuration which you may have configured in the Runtime Port Config menu or with the SETPORT setportcfg functions If a program is running under the Executive the Port 1 configuration operative during the program s execution will be the Executive configuration However if the program is running in autoexec mode then the Port 1 configuration will be the Runtime Port Config configuration The reason for the above implementation is to support testing of programs when using KTERM with a command line baud rate specification For example if you are running KTERM with a b38400 specifica
131. f the 8 bits constituting the two chars and returns the char result _CPLC char bit wise complement FUNCTION _CPLC VALUE CHAR CHAR This inverts the bits in the char VALUE and returns the char result PPC PASCAL 6 35 _SHLC char shift left FUNCTION _SHLC VALUE PLACES CHAR CHAR This shifts VALUE left by PLACES bit positions with zero fill and returns the char result Any carry out from the top bit bit 7 is discarded This function is faster than the alternative shifting left by multiplying by a power of two Only the three least significant bits of PLACES are used limiting it to 0 7 See the _BITC function for information on specifying the PLACES variable _SHRC char shift right FUNCTION _SHRC VALUE PLACES CHAR CHAR This shifts VALUE right by PLACES bit positions with zero fill and returns the char result Any carry out from the lowest bit bit 0 is discarded This function is faster than the alternative shifting right by dividing by a power of two Only the three least significant bits of PLACES are used limiting it to 0 7 See the _BITC function for information on specifying the PLACES variable _ROLC char rotate left FUNCTION _ROLC VALUE PLACES CHAR CHAR This rotates VALUE left by PLACES bit positions and returns the char result Any carry from bit 7 is fed back into bit 0 Only the three least significant bits of PLACES are used limiting it to 0 7 See the _BITC function for information on
132. fTypes Insect Frog Fish Mammal ANIMAL RECORD LEGS INTEGER NAME ARRAY 1 20 OF CHAR ANIMAL ListOfTypes END will cause an error as ANIMAL is used both as the type name and as a field identifier Likewise TYPE one RECORD x y INTEGER END two RECORD Z y INTEGER END will cause an error as y exists in both records However any program which duplicates names in this way would be very confusing Records may have variant parts as per Standard PASCAL Two record types are only treated as equivalent if their declaration stems from the same occurrence of the reserved word RECORD See ARRAYs and SETs section for an explanation of this The WITH statement may be used to access the different fields within a record in a more compact and faster executing manner than the alternative e g ANIMAL LEGS PASCAL format FIELD LIST When used in conjunction with RECORDs see RECORDS section PPC PASCAL 6 9 VARIABLE variable identifier field identifier expression Two kinds of variables are supported within PPC PASCAL static and dynamic variables Static variables are explicitly declared through VAR and memory is allocated for them during the entire execution of the block in which they were declared Dynamic variables however are created dynamically during program execution by the procedure NEW They are not declared explicitly and cannot be referenced by an identifier They are
133. fer the program to a PC rename its filetype and transfer it back to the PPC The PPC rigidly enforces its language rules only a BASIC program can be loaded into the BASIC Interpreter only a PASCAL program can be compiled by the PPC PASCAL compiler Note that there are two other ways of creating PPC programs 1 In PPC BASIC the SAVE command will create a program with the Basic attribute 2 When a BAS or PAS file is transferred from a PC to the PPC with KTERM a program with a Basic or Pascal attribute respectively is created 3 Edit program Pressing J when this item is highlighted enters the PPC Editor and opens up for editing the program which is currently selected in the directory The editor command set is partly Wordstar 4 compatible use CTRL K Q Y to exit the editor without saving any changes For full details see the PPC Editor chapter 4 Compile only Pressing J when this item is highlighted invokes the PPC PASCAL compiler and compiles the program which is currently selected in the directory it must be a PASCAL program For full details of the PASCAL compiler please see the PPC PASCAL chapter At the end of a successful compilation the message Press any key to return to Executive appears If errors occured during compilation the compiler error message is followed by ESC gt EXECUTIVE C gt continue compilation E gt Editor and you have the option to directly enter the editor where the cursor will be automa
134. fier since it does not have an identifier instead a pointer variable is used This pointer variable which is a static variable contains the address of the dynamic variable and the dynamic variable itself is accessed by including a after the pointer variable There are some restrictions on the use of pointers within PPC PASCAL Pointers to types that have not been declared are not allowed This does not prevent the construction of linked list structures since type definitions may contain pointers to themselves e g TYPE item RECORD value INTEGER next item END link item Pointers to pointers are not allowed Pointers to the same type are regarded as equivalent e g following the above declaration with VAR first link current item is valid The variables first and current are equivalent i e structural equivalence is used and may be assigned to each other or compared The predefined constant NIL is supported and when this is assigned to a pointer variable then the pointer variable is deemed to contain no address FILEs All 1 0 in PPC PASCAL is done with file reads and file writes The character based stream 1 0 environment in which the PPC operates is different from the environment on a PC i e reading and writing disk based files and it is therefore in the I O area where PPC PASCAL differs the most from Standard Pascal There are important concepts which you must understand about PPC file 1 0 1 Since a
135. fy control characters in the find and substitute strings in the same way as above An obvious use for this feature is to find the end of line character reached by meta key J or meta key CTRL M The character when pressed after the meta key returns FFh This character is displayed as in the find and substitute strings but is treated as a wild character in the find string i e it will match with any character at all in the file If your terminal is capable of producing characters of value greater than 127 decimal then these characters are entered as any other into the file and are displayed according to the capabilities of the terminal With KTERM this allows the entry of international characters e g a Note that such characters should be used only in quoted strings in e g WRITE statements they must not be used in Pascal or Basic variable names 4 8 The Editor PPC BASIC What is PPC BASIC BASIC is a simple and very popular easy to learn programming language developed in the 1960s which is provided in the PPC for users who need to write only relatively small programs and who perhaps have some knowledge of BASIC already The PPC BASIC is a subset of standard BASIC known as Tiny Basic The main difference between PPC BASIC and a full featured BASIC language is that PPC BASIC supports integer variables only no floating point numbers or strings and it supports only a core subset of the functions found in full featured person
136. ght be tempted to think that you could write A B but this would generate an error in PPC PASCAL since two separate TYPE records have been created by the above definitions In other words you have not taken the decision that A and B should represent the same type of data You could do this by VAR A B ARRAY A C OF INTEGER and now you can freely assign A to B and vice versa since only one TYPE record has been created Although on the surface this name equivalence approach may seem a little complicated in general it leads to fewer programming errors since it requires more initial thought from the programmer Semicolons A semicolon should not appear before UNTIL or before END or before ELSE Versions of PASCAL differ in their treatment of this PPC PASCAL allows semicolons before UNTIL END but reports an error if a semicolon appears before ELSE PPC PASCAL 6 15 Predefined Identifiers Constants MAX INT The largest integer available 32767 TRUE FALSE Constants of type Boolean PPC PASCAL has many other constant predefined identifiers e g of type TEXT which are used in PPC port initialisation and control procedures See the PPC PASCAL Extensions section for details All of these start with an underscore _ except PORT1 PORT2 PORT3 PORT4 Types INTEGER See Unsigned Number section REAL See Unsigned Number section CHAR The full extended ASCII character set of 256 elements BOOLEAN This type is used in logical op
137. hich s not being retrieved by your program fast enough The DSR signal not connected is not generally useful although its function can be programmed on some modems The DTR signal is programmable on most modems It can be used to force the modem to hang up without using the ime consuming sequence which would be necessary otherwise The modem s CD carrier detect signal can be monitored by the PPC and provides an accurate indication of the modem s online offline status With internally buffered modems the PPC modem baud rate can be much higher than the data rate on the telephone line The modem will handshake the data as required using CTS Since no handshake system exists over a telephone line any data which the modem receives from the telephone line is immediately passed to the PPC and enters the PPC s 255 byte RX buffer To avoid buffer overflow the PPC s program must promptly read this data and should not rely on any handshakes to hold up the data flow Modems vary a great deal in their functions and most have a large number of software programmable features These features must be correctly configured Please read your modem programming manual Ensure that your PPC modem cable has only those connections actually required for the job Many modems have signals additional to those shown above and some special purpose modems have test voltages present on certain pins A connection of such voltages to the PPC will damage the PP
138. hted enters a function which allows the time and date in the PPC real time clock RTC option to be configured 3 8 The PPC Executive aa The suggested procedure is to set up a particular time and when that time is reached according to a reference clock press ESE to load it into the RTC You must ensure that the day of week is set correctly for the date being entered The PPC does not check it The lithium battery should last for around 20 years If you have to replace it or if it has been short circuited for any length of time run the reset R command This re initialises the RTC hardware lf your PPC does not contain the factory fitted RTC option a message to that effect appears 10 8 Analog Port tests A option Pressing J when this item is highlighted enters a function which displays the value returned by the eight analog digital converter ADC channels AIN1 AIN9 plus the value returned by the on board temperature sensor channel 9 in the following format CH 1 CH 2 CH 3 CH 4 CH 5 CH 6 CH 7 CH 8 CH 9 00005 04726 00001 17756 18188 18144 18284 18543 01978 In addition the values read on ADC channels 1 2 are copied to the digital analog converter DAC channels 1 2 where they can be measured with external equipment To interpret the above readings use these formulae volts reading 32768 temperature C reading 2 5 2048 The calculated values are uncalibrated and will therefore not be p
139. ich represent an integer is read All preceding blanks and end of line markers are skipped If the integer read has an absolute value greater than MAXINT 32767 then the runtime error Number too large will be issued and execution terminated This error can be suppressed with the O compiler option If the first character read after spaces and end of line characters have been skipped is not a digit or a sign or then the runtime error Number expected will be reported and the program aborted This error can be suppressed with the R compiler option 4 V is of type real Here a series of characters representing a real number will be read All leading spaces and end of line markers are skipped and as for integers above the first character afterwards must be a digit or a sign If the number read is too large or too small then an Overflow error will be reported can be suppressed with the O compiler option if E is present without a following sign or digit then Exponent expected error will be generated and if a decimal point is present without a subsequent digit then a Number expected error will be given The latter two errors can be suppressed with the R compiler option READLN This is identical to READ except that when called it discards all input characters up to and including a CR following which its operation is as READ It is not particularly useful in PPC applications BREAD PROCEDURE BREAD PORT TEXT V1 V2 V3 Vn This
140. imes out and does something else For an example of this see the LOADTIMER and READTIMER functions When used in conjunction with the OPQSPACE function this function also permits the construction of a program which services multiple ports in an apparently multitasking manner For an example see OPQSPACE below After this function has been invoked the number of bytes in the input queue may increase as a result of new input data arriving but it can never decrease except by being read by your program IPQCLEAR clear input queue PROCEDURE IPQCLEAR PORT TEXT This procedure clears out any unread data in the specified port s input queue OPQSPACE test output queue space FUNCTION OPQSPACE PORT TEXT INTEGER Each PPC port has a 64 byte output queue which is emptied under interrupts to the output device handshakes permitting Four bytes are always kept unused If there is any room in this queue this function will return an integer in the range 1 60 If the queue is initially empty a program can freely generate up to 60 bytes of output data even if the output device has been busy all the time This function allows a program to check if there is any room in the specified port s output queue It allows a program to write output data only when there is room for it rather than hang until room becomes available When used in conjunction with the PPC timers this function permits the construction of a program which t
141. imes out if the output device has been busy for too long When used in conjunction with the IPQCOUNT function this function also permits the construction of a program which services multiple ports in an apparently multitasking manner The following example shows a trivial multitasking program which copies data PORT1 gt PORT2 and simultaneously PORT3 gt PORT4 and which can never hang 6 28 PPC PASCAL procedure copydata p_in p_out text var c char begin bread p_in c bwrite p_out c copy a char p_in gt p_out end repeat if ipgcount port1 gt 0 and opqspace port2 gt 0 then copydata port1 port2 if ipqcount port3 gt 0 and opqspace port4 gt 0 then copydata port3 port4 until false Note how copydata is invoked only if there is some input data and if there is room for output data This important principle can be extended to produce sophisticated multitasking like programs After this function has been invoked the amount of space in the output queue may increase as a result of data being output but it can never decrease except by being filled by your program OPQCOUNT get bytes in output queue FUNCTION OPQCOUNT PORT TEXT INTEGER This function is the complement to OPQSPACE It returns the number of bytes of data currently in the output queue To assist special programs which must at times ensure that the output queue is completely empty this function has been carefully im
142. in on a PC using any non document editor or word processor and then be uploaded to the PPC In the PPC EXECUTIVE using the gt directory file selector select the desired PASCAL program Choose the Compile function If errors are found use the editor to correct them When a program compiles with no compilation errors you can proceed to the Compile and Run function and run the program When you have finished the program and it is working as it should you can designate it to be an autoexec program see the PPC Executive chapter and it will then execute automatically whenever the PPC is powered up PPC PASCAL 6 1 PPC PASCAL Introduction PPC PASCAL is a very powerful tool that enables you to build highly structured and easy to understand programs that run very quickly However as with any computer language it is going to take you some time to get used to using PASCAL Therefore we strongly recommend that you adopt the following procedure when using PPC PASCAL for the first time 1 Work through the entire Get Started chapter 2 Read the PPC Editor chapter and work through the Editor tutorial 3 Read the rest of this chapter trying out the quick program below until you understand how a PASCAL program is created compiled and executed 4 Repeat the above steps until you feel comfortable using the editor and compiling running a PASCAL program A Quick Program First we will create a trivial program called TEST1 On th
143. ing Finally the file is searched for the next occurrence of the Find string starting from the cursor CTRL 0 A Starting from the cursor all occurrences of the Find string in the file are replaced by the Substitute string A wild character in the Find string will match with any character at all in the file The cursor is then placed after the last string substituted You should never insert control characters into program files They can cause errors which can be extremely difficult to find While a file is open in the editor its lines end with a lt CR gt not lt CRLF gt Normally you do not need to know this but it is relevant if you are searching for end of line characters 4 4 The Editor Leaving the Editor Exit and abandon Exit and save CTRL K Q You are asked whether to abandon the file Pressing Y will cause a return to the Executive and the current text will be abandoned Any other response will abort the command CTRL K X The file being edited is saved in the filing system If there is insufficient space an error message will appear In such a case you must remove some text or abandon the file Do not disconnect PPC power while a file is being saved Doing so will almost certainly result in loss of data and the loss will not be limited to the file you have been editing Toggles Toggle insert mode Toggle auto indent Toggle free space display CTRL V or INSERT Switch between INSERT and CHA
144. ing seconds elapsed since year 1900 or similar Some additional ANSI C functions which provide additional support are defined in ppclib h and are provided in a separate library ppcextra lib which must be linked to your program Checksums and CRC Many data communications systems use checksums or CRCs to ensure data integrity A CRC function in particular is inefficient to implement in C and the following functions written in assembler are therefore provided 12 4 C Reference unsigned char sumbuf char bufname int buflen unsigned char xorbuf char bufname int buflen unsigned int crcbuf char bufname int buflen int initvalue For a more detailed description see the similarly named functions in the PPC Pascal section Bit Operations and Rotation These operations are not provided in standard C and although they are easy to implement in C the following self explanatory functions have been provided for convenience and for performance critical applications int testbit16 int bitnum unsigned int value returns 011 int testbit8 int bitnum unsigned char value returns 011 unsigned int rotleft16 int rotations unsigned int value unsigned int rotright16 int rotations unsigned int value unsigned char rotleft8 int rotations unsigned char value unsigned char rotright8 int rotations unsigned char value Extended Memory Functions The PPC 96 option provides extra 96k bytes of RAM Th
145. inport c if c a then c b translate a into b bwrite outport c until false If several or many characters need translating multiple IF statements are cumbersome For the translation of several characters a CASE statement is better repeat bread inport c case c of a c b convert a to b x crety s convert x to y Z cr convert z to end bwrite outport c until false However for the translation of many characters a translation table must be used This is a 256 byte array which at initialisation is preloaded with the output characters The input character forms the index into the array The resulting program the repeat until loop is very fast xltab array 0 255 of char c char i integer PPC PASCAL 6 53 Preload the table with 1 1 translation i e no translation for 1 0 to 255 do xltab i chr i Define the chars to be translated xltab 65 z 65 is A translate it to z xltab 0 translate a null char to xltab 7 translate a BELL to xltab 35 etc init xltab 135 fgtkym this defines input chars 135 140 The main program repeat bread inport c read a char c xltab ord c translate it bwrite outport c output it until false String translation This can be done is many different ways depending on whether the input data can be read one line at a
146. inputchar write it into EEPROM nvaddress nvaddress 1 EEPROM address 1 wait for a char chrcount chrcount 1 char counter 1 until chrcount 0 or retcode lt gt 0 and repeat if retcode lt gt 0 then optional retcode test writeln portl NVWRITEC error retcode if error report Note how the above program tests the return code This should always be done at least during program debugging NVREADC read a char FUNCTION NVREADC EEPROMADDR INTEGER VAR C CHAR INTEGER This function is the opposite of the NVWRITEC function above It reads a character from the EEPROM The following code will print out the data stored by the above NVWRITEC program repeat retcode nvreadc nvaddress inputchar read the EEPROM write portl inputchar nvaddress nvaddress 1 chrcount chrcount 1 until chrcount 0 or retcode lt gt 0 if retcode lt gt 0 then writeln portl NVREADC error retcode NVWRITEI write an integer output the char to P1 EEPROM address 1 char counter 1 and repeat optional retcode test if error report FUNCTION NVWRITEI EEPROMADDR VALUE INTEGER INTEGER This is identical to NVWRITEC except that two bytes representing an integer are written Execution time is 20ms max 10ms typ Note that valid addresses are 0 1998 decimal mot 0 1999 The ower less significant byte of the integer is stored at the ower address although you woul
147. ion error PASCAL only EER An execution error run time error NPR The PPC was configured to autoexec a program but the program is missing USR User accessible LED Can be switched on off from PASCAL and C programs EXE Flashes when the PPC is in the Executive RST The PPC is being reset ON when SW2 SW3 depressed together for 1 second PWR Power input Always ON When the PPC is running a BASIC program COM amp PGM are ON together because BASIC is an interpreter and is therefore effectively both compiling and executing the program The EER indicator is latched If a runtime error occurs in a program it remains on until the program terminates In PASCAL runtime error trapping can be disabled see the PPC PASCAL chapter and doing so also disables this front panel indication The PPC E has a second LED bar display The top eight LEDs indicate TX RX activity on each of the four ports These eight LEDs can also be accessed directly from C programs 1 2 PPC Overview Options PPC 4 The standard PPC 4 is a four port product which replaces the previously offered PPC 2 and the 4 option A number of factory fitted options are available including the following R suffix A lithium battery powered real time clock Allows PASCAL and C programs access to date and time H2 suffix Higher speed version 100 increase in CPU speed H3 suffix Higher speed version 200 increase in CPU speed C suffix The ROM includes the
148. ion string to be specified This string is used only in the Print Program 6 2 function The string is displayed in hex only but can be entered in a mixed format 78 is a decimal number and gives N 4E is a hex number and also gives N digits A F must be UPPERCASE N is a quoted character and also gives N AbC defines a 3 character string AbC Note that with quoted characters or strings both single and double quotes may be used provided they are matched This also facilitates the easy inclusion of a quote character within a string The maximum length of the string is 20 bytes The following example defines the factory set printer initialisation string which is for the HP Laserjet II III printer family 1B E 1B s16 66H 1B 218D 10 6 Executive Mode Port 1 config Pressing enters the configuration screen for Port 1 The settings herein apply in EXECUTIVE mode only Only the baud rate may be altered 1200 38400 baud The other parameters are fixed at 8 bits word no parity 1 stop bit TX XON XOFF and TX CTS enabled Very Important Do not alter the baud rate away from 9600 baud unless you are using either a dumb terminal or a non KTERM emulator The supplied KTERM EXE program is capable of changing the baud rate temporarily up to 38400 baud for the duration of the KTERM session but it assumes a 9600 baud initia setting 10 7 Set real time clock option Pressing when this item is highlig
149. ions oo aaa o 12 3 10 Port Configuration RUNCUONS ttre Aad eee de Ge A hoteles 12 3 0 Port Direct Handshake Control cs eto Gace oh ae Got arg a vod Sead ne ee he Noe Bones 12 4 Break A Aian A A hbk act a Bk Getto Bok Ger deat 8 12 4 AMINO RUNCUONS sects rr a a ale ded aida de mad 12 4 Real Time Clock FUNCHONS gt a Lo aan deta das a a 12 4 A A O Oe eae E 12 4 Bit Operations and Rotation o 12 5 Extended Memory FUNCHIONS so eenk E AS aie ah Ya aS be A a Oe 12 5 MISCENANEOHS FUNGHONS Seti On cay ares a sie omg ee hse Aine aan AI ee eee a 12 5 DESEnGryplionsFURCHONS ato ds St nad y 12 6 MISCBIIANGOUS ica Ss a ta da 12 7 PPRCEXTRALIB Extra Library rr da e Bw o Sch ede AR 12 7 Checking of printf type Function Parameters ooa aaa a a 12 7 Ferformance MINS e e 40 a a a oe A A ita 12 7 CA A A Ae hat ee de Aea 12 7 PG Character Godas s dresas a o A RE 13 1 RE aen ak E oe yok e Blick age EM ee aA eee ae Lad 1 1 Inline RS232 RS4xx Converters AA AR ee ROE A 1 1 KB485 DIN BACON VE od a la id iaa a 1 1 PPC Overview What is the PPC The PPC is a user programmable protocol converter Data received on a communications port can be modified as required and output on another communications port The modification is done by a BASIC PASCAL or ANSI C program written by the user In a compact self contained unit the PPC integrates all functions required to develop the required BASIC or PASCAL programs to execute
150. ipped with two hardware handshakes and an XON XOFF handshake for both transmit and receive modes Therefore each port supports up to a total of six distinct handshakes each of which can be individually enabled or disabled The only exceptions are the Port 1 amp 2 CTS TX handshakes these cannot be disabled Since there is no standard on handshaking you will generally have to examine what handshakes the other devices require or support and enable those handshakes only on the PPC In many cases only a small subset of the PPC s handshake modes will be enabled although it usually does no harm subject to the cables being correct to simply enable them all The following is a detailed description of the handshakes operation TX Handshakes The PPC transmits data from the TX pin only if all enabled TX handshakes are READY RS 232 high level or XON TX handshakes which may be enabled are CTS DSR and XON XOFF More than one TX handshake may be enabled In any handshake system there is a delay between the handshake s change of state and how long it takes for the transmit data flow to start stop The following approximate timings apply to the PPC Port 1 amp 2 CTS TX handshake data flow starts stops within 1 character period All other CTS amp DSR TX handshakes data flow stops within 4 character periods data flow restarts within 1 ms XON XOFF handshakes data flow stops within 5 character periods data flow restarts within
151. is additional RAM is not used by anything in the PPC The following functions access this extra memory as a linear 96k byte array of chars a random access file unsigned char readmem unsigned long address void writemem unsigned long address unsigned char chartowrite where address can be any value 0 98303 Miscellaneous Functions The following function returns the states of the three front panel switches into a structure defined in ppclib h sw_t void getsw struct sw_t anyname The following function copies status 0 or 1 into the front panel LED labelled USR void uled int status Other functions enable direct access to all eight front panel LEDs or all 16 if it is a dual display PPC The following function fills in a buffer with information on the PPC firmware version number of ports firmware date CPU speed PPC serial number and other data int sysdata char bufname At present a buffer of approximately 23 bytes is required sysdata 0 returns the exact size See the example program test c for more details The following two functions support the PPC Digital 1 0 Card Type 1 unsigned int pdin void read 16 inputs void pdout unsigned int bitpattern set 16 outputs For a more detailed description see the similarly named functions in the PPC Pascal section The following functions support the PPC 16 bit Analog Subsystem int readadc void read ADC calibrated int re
152. is explained below Cables A cable suitable for connection between an IBM PC 25 way serial port and a standard Hayes compatible asynch modem is below The same cable can also be used for the connection between the remote modem and the PPC PPC 9 way or PC 25 way MODEM 5 147 GND GROUND GND 147 e 9 1X TX DATA TX 2 a A RX DATA RX 3 OTN FS ALWAYS HIGH RTS 4 IES 8 5 crs TX HANDSHAKE CTS 5 TELEPHONE a 20 DTR ALWAYS HIGH DTR 20 6 161 DS IGNORED BY KTERM PPC DSR 6 9 11 CDO M lel Col CARRIER DETECT Co 8 PPC configuration It is assumed that you want to access the PPC Executive over the modem link and edit files with the PPC editor perform PC PPC file transfer etc and not just communicate with a program which is running in autoexec mode You must therefore configure the Executive Mode baud rate to match the modem s configuration In addition you may want to see data which is emitted by your program to the Executive port Port 1 and you must therefore configure the Runtime baud rate of Port 1 to match the modem s configuration also Where configuration is possible use 8 bits word 1 stop bit no parity RTS CTS handshake ON XON XOFF handshake OFF Use the highest baud rate which your modem supports The PPC port Port 1 should be configured with the following handshakes RX handshakes RTS DTR XON XOFF TX handshakes CTS DSR XON XOFF ON OFF OFF ON OFF OFF The Executive Mode bau
153. isplayed followed by at PC XXXX where XXXX is the approximate program address at which the error occurred Note that in certain cases XXXX may be inaccurate when you have broken out of a program with ctrl c then the address given may be that of the low level 1 0 routine rather than the address of the READ etc statement which was executing or it could be entirely inaccurate All runtime error messages are sent to Port 1 Halt Overflow Out of RAM DIV by Zero Index too Low Index too High Maths Call Error Number expected Number too large Exponent expected PPC PASCAL 6 49 Reserved Words and Predefined Identifiers Reserved Words gt gt AND ARRAY BEGIN CASE CONST DIV DO DOWNTO ELSE END FOR FORWARD FUNCTION GOTO IF IN LABEL MOD NIL NOT OF OR PACKED PROCEDURE PROGRAM RECORD REPEAT SET THEN TO TYPE UNTIL VAR WHILE WITH Special Symbols The following symbols are used by PPC PASCAL and have a reserved meaning lt gt lt lt gt gt o aa A Predefined Identifiers The following entities may be thought of as declared in a block surrounding the whole program and they are therefore available throughout the program unless re defined by the programmer within an inner block CONST MAXINT 32767 TYPE BOOLEAN FALSE TRUE CHAR The expanded ASCII character set INTEGER MAXINT MAXINT REAL A subset of the real numbers The following special TYPEs are also predefined as p
154. it of the integer corresponds to bit 0 of the port Further information on the DG1 card is in the 1 0 Expansion Options chapter 6 40 PPC PASCAL EEPROM non volatile access functions The following functions support the storage and retrieval of data in a specially reserved 2000 byte area of the EEPROM non volatile memory address 1999 address 1998 2000 bytes of random access non volatile storage address 3 address 2 address 1 address 0 This is a very useful feature which permits the construction of a device which can self modify its properties and retain the changes through power down Examples include the storage of passwords in a security device or the storage of calibration coefficients for the analog subsystem Before using any of these functions you must understand that an EEPROM is not the same as a RAM even though the functions provided do allow the EEPROM to be treated as a random access device The following considerations are most important LIMITED WRITE ENDURANCE An EEPROM has a limit on the number of writes which can be done on any particular address If this limit is exceeded the EEPROM may be permanently damaged The write limit in the device used in the PPC currently XICOR 280256 is guaranteed at 10 000 writes although manufacturers data shows that failures do not typically occur until the number of writes to the same location is well past 100 000 This limit applies on a per ocation
155. itialises member n initialises member p initialises member q init rec somedata 23 25 27 2567 123 2 5 3 6 45E7 0 05e 8 PS m AS AS SUMBUF compute a checksum over a buffer FUNCTION SUMBUF START SIZE INTEGER CHAR This function computes a MOD 256 checksum over a buffer containing char data The parameter START is the address of the buffer The following example computes the checksum over 399 bytes of data and places the result into the last byte var buffer array 1 400 of char buf fer 400 sumbuf addr buffer 399 XORBUF compute a XOR over a buffer FUNCTION XORBUF START SIZE INTEGER CHAR This function computes a XOR over a buffer containing char data The parameter START is the address of the buffer The buffer size must be 2 or greater The first character is XORed with the second the result is XORed with the third the result of that is XORed with the fourth etc Example buf fer 400 xorbuf addr buffer 399 CRCBUF compute a CRC over a buffer FUNCTION CRCBUF START SIZE INITIAL INTEGER INTEGER his function computes a 16 bit CRC over a buffer containing char data The parameter START is the address of the uffer The value INITIAL is the initialisation value for the CRC generator The algorithm used is based on the standard RC polynomial x16 x15 x2 1 his CRC is not the one used in MODBUS messages he following example loads the CRC of a 400 byte buffer computed over its firs
156. ition CTRL Q R or HOME CTRL Q C or END CTRL Q F This is really a define Find and Substitute strings command The current Find string is displayed J retains the current string otherwise you should type in the required Find string up to a maximum of 32 characters and then press J BACKSPACE operates CTRL R will redisplay the previous string and CTRL U will abort the operation A control code may be entered by pressing the control meta key CTRL P see Miscellaneous and then the control character e g CTRL P then enters a lt CR gt into the string Pressing the meta key and then will return a value which is displayed as and counts as a wild char when in the Find string After is pressed a prompt for the Substitute string appears If you only require Find and do not want to Sunstitute anything press J The cursor will be positioned at the start of the first occurrence of the Find string in the file CTRL L The file is searched for the next occurrence of the Find string starting from one character after the cursor A wild character in the Find string will match with any character at all in the file CTRL 0 L The file is searched starting from the cursor for the next occurrence of the Find string A wild char in the Find string matches any character in the file When the string is found it is replaced by the Substitute string and the cursor is positioned after the last character of the Substitute str
157. itor then transferred to the PPC The Look of the Editor PROGRAM NAME CURSOR POSITION MODE MESSAGE AREA PRIMES LINE 1 COL INSERT program primes C L CONST w 50 w 1 x500 gives the number up to which primes are found For each increment of w 32 bytes of storage are needed The largest w value for the PPC is about 305 3 FILE WINDOW max 8 maximum number of primes to be displayed on one line VAR Sieve ARRAY 9 1 OF SET OF 0 249 fSieve in which the primes are contained Count 1 max Number of primes on this line high low INTEGER The upper and lower parts of the current prime word bit INTEGER The current position in te sieve jk INTEGER The current position that we are deleting from the sieve t c INTEGER Temporary storage for initialise and how many elements t empty BOOLEAN Is the Sieve empty flag BEGIN Initialise FREE 28133 3 FREE SPACE FIND STRING SUBSTITUTE STRING The screen is effectively a window into the file This window may be moved in all four directions so that you can view any part of the file Sideways scrolling is supported Initially the editor assumes that a 25 line terminal is being used and configures its screen layout accordingly If KTERM is used KTERM will tell the PPC the screen size of the current KTERM session and the editor will auto configure to the new screen size Within KTERM the screen sizes can be
158. ive the record a name retcode integer this accepts any setrtc errorcode with anyname do begin now we fill up the record as required tm_sec 55 tm_min 48 tm_hour 18 tm_mday 9 10th day 9 tm_mon 4 May 5th month 4 tm_year 102 tm_wday 0 Sunday 0 end PPC PASCAL 6 29 IS IS retcode setrtc anyname this actually loads the clock if retcode lt gt 0 then optional check on setrtc errorcode writeln port1 SETRTC failed You must define the values of all the seven parameters before calling SETRTC Uninitialised parameters are undefined and will have unpredictable results Years over 1999 be careful to specify the year since 1900 correctly Year 2005 is specified as 105 It is also important that your program handles this correctly it is no good to store only 2 digits for the year and expect the date to correctly roll from 1999 to 2000 The best way to store the year value is as a full integer equal to the actual year and any year related text in the user interface should show the full 4 digits too The RTC in common with most RTC chips on the market stores the year as only two BCD digits 00 99 PPC firmware supports years past 1999 by adding an offset of 50 thus supporting years 1950 2049 This is done transparently and you need to know nothing about it If SETRTC returns a non zero return code i e an error code this indicates that some of the parameters are invalid and the cloc
159. k will not have been accessed A non zero return code can also indicate that the RTC option is not installed GETRTC read real time clock FUNCTION GETRTC VAR T RTCTYPE INTEGER This function reads the PPC real time clock into the same record which is used for SETRTC A non zero return code indicates that the RTC option is not installed LOADTIMER load a timer PROCEDURE LOADTIMER TIMERNO VALUE INTEGER The PPC provides eight timers numbered 0 7 which are decremented to zero and which provide 1ms resolution Because the timers are decremented in the background i e with interrupts the PASCAL program having started a timer by loading a non zero value into it is free to do anything while the timer is being decremented and it needs to test the state of the timer only occassionally Delays up to 65535ms are possible delays over 32767ms will involve negative timer values The timer is decremented to zero only the expiration of a timer is detected with the function READTIMER returning a zero value If an invalid timer number is specified this procedure has no effect The 1ms increment is not affected by the H2 or H3 PPC options which merely increase the CPU speed The timer is decremented every 1ms i e with 1ms resolution Therefore if you load a time constant of e g 3 then the actual delay before the timer reaches zero could be between 2ms and 4ms Very short time delays are not exact and the minimum time constant which
160. l 2 6 7 PU ETE Sng AO ep devin gs ae erty ernst sy ge PRE A NRO Ae a aioe E E AN 6 7 RECORDS a Gan ds A A A hing UA aoe aah A A boe f 6 9 AAA A A A ont dh ae Ootrh are as BBD Gree ea 6 9 VARIABLE ny of 0 A ash ah tie a heh ag eve Mat tanec aa db 6 10 FACTOR A aa ES Soak Meat cae heap apn Oo BAe te wie ec ee te PAO te shay Se At Se 6 10 TERM o a os Ue be cg RO HH ay Bh og Ewch oe GF Hp ahah Woh Gk ede Wh rh oe AN 6 11 SIMPLEEXPRESSION a ae ee eds Ae A Se tld Me a 6 11 EXPRESSION o A dd iia Sen 6 11 PARAMS lips vgn Ara a A es rs dd 6 11 STATEMENT a a Ad dd de A dt 6 12 Assignment Statements icia ai a a db ada 6 12 GASE SEALCMONIS sto iaa rd a ia nd at Gee da ed 6 12 FOR Statements s o serra es at a a beba mai A il 6 13 GOTO STATO MOIS uote ra a aad das asis o et e ds 6 13 WITH SIU MIGM Sic 258 aks las A Se Rat oy a loss et doce GE HR gw ted rae a TU os EA 6 13 BI eke or ak SiN cet col E Bete gh ae atte E A A 6 14 ANI A Ss tact aha Bethe lg A A 6 14 PROGRAM ras Mt oe atop toa a SESE nit ame ah Adee Se Ra ie hak aA ee 6 15 Sitong LY PENG A oe Go Soa A ah AE Oy Ne ea a at ate a a SOR 6 15 SEMICON tia E ends Sen ep ae Rah Gare ante Goring ead 6 15 Rredetined den pe da lr a heehee da bo ay heed 6 16 A IN E E E E 6 16 DES Aone acia ada o e dah sends E AA Ak a do a LO a a es Atel A A he 6 16 Maa a adas la EE ia ered 6 16 PROCEDURES AND FUNCTIONS 00 emanadas ne 6 16 File Handling Procedures sc ore Gog te Sede tne a e edd aca Sota
161. lar value thus producing consistent results whenever the program runs GET This function reads input data from a PPC port X GET 3 returns a character in X value 0 255 from port 3 or X 1 if no character was waiting on port 3 The advantage of GET as compared to WGET below is that if no input character is waiting the BASIC program can go away and do something else that may be useful WGET This is similar to GET but it waits until a character arrives on the specified port The commands 10 X GET 3 20 IF X 1 GOTO 10 are equivalent to 10 X WGET 3 The WGET command will cause the BASIC program to hang until data appears on the input ADC This function reads the PPC 16 bit analog digital converter ADC The ADC is available only if the ANALOG SUBSYSTEM option has been fitted otherwise its execution will generate a fatal error X ADC 6 returns a reading in X from channel 6 AIN7 of the ADC Returned values are in the range 32767 to 32767 corresponding to nominal input voltages 1V to 1V ADC channel numbers are ADC 1 to ADC 8 corresponding to analog connector pins marked AIN1 AIN8 The 9th channel X ADC 9 returns an integer which is proportional to the temperature of the analog module for temperature compensation of ADC readings However due to the lack of floating point support in PPC BASIC little use can be made of this feature from within BASIC SWI This returns an integer corresponding to the stat
162. layed next to it If the gt marker is not next to the program correct this by highlighting the correct program and pressing J Highlight the Edit Program item and press J This enters the PPC editor which displays a blank screen with the program name at top left Full details of all editor commands are in the PPC Editor chapter but here we will use only a small subset The editor commands are a subset of those used in Wordstar 4 Type in the following simple program Upper lowercase is unimportant The indenting done with the TAB key is also unimportant but is common in Pascal as it helps to make the logic of a program more obvious program btocp var c char begin writeln portl READY repeat read port1 c if c B then c C write portl c until false end Save the program and exit the editor with CTRL K X first type K while holding down the CTRL key and second type X just by itself Back in the Executive main menu you will again see the program BTOCP in the directory but this time with a size of around 100 bytes Highlight the Compile Only item and press to test compile the program No errors should be reported If any are reported select the E option to re enter the editor and correct the error When the Compile Only function completes with no errors proceed to Compile and Run The program is now running and as with the BASIC example earlier every character you type is echoed except B which is changed to
163. ll input is byte serial i e comes in one byte at a time there is in general no way of detecting the end of an input file of calculating its total size or accessing data at random in different parts of the file This may seem obvious but needs to be stated 2 The type of a PPC PASCAL file i e the interpretation of its content is whatever you want it to be If you output non printable binary data e g with BWRITE then that file in effect becomes a binary file If you output text only printable data e g with WRITE or WRITELN the file will in effect become a text file The same applies to reading This is contrary to Standard Pascal where files may contain printable data only and which does not allow you to input or output arbitrary binary data It is also contrary to the extensions provided in many Pascals which support the reading and writing of various binary variables 3 There is no support for file operations on the PPC filing system All file 1 0 applies to its external data 1 0 ports only Non volatile data storage is possible and is supported with the NVREAD NVWRITE etc procedures PPC PASCAL 6 7 aj aj 4 All PPC file 1 0 is done only with the following routines READ READLN Standard PASCAL procedures for reading text data BREAD Special PPC PASCAL extension for reading binary data WRITE WRITELN Standard PASCAL procedures for writing text data BWRITE Special PPC PASCAL extensio
164. ll scalar types Sets may be compared using gt lt lt gt or Pointers may only be compared using and lt gt PARAMETER LIST type identifier A type identifier must be used following the colon otherwise an error will result Variable parameters as well as value parameters are fully supported Procedures and functions are not valid as parameters Files can only be used as variable parameters not as value parameters PPC PASCAL 6 11 STATEMENT La E ae expression Assignment statements See the TYPE RECORD sections for information on which assignment statements are valid When assigning to subrange variables the value is not checked for being within the subrange for efficiency reasons CASE statements An entirely null case list is not allowed i e CASE OF END will generate an error 6 12 PPC PASCAL The ELSE clause which is an alternative to END is executed if the selector see the Expression syntax diagram is not found in one of the case lists This is analogous to the C default feature and is additional to Standard PASCAL which to be safe requires a CASE statement to be preceeded by a check to ensure the selector is within the range of the CASE statement If the END terminator is used and the selector is not found then control is passed to the statement following the END Note that you should not have a semi colon before the END of a CASE statement FOR statements
165. n product Step 1 Software Installation The supplied diskettes contain executables which are relevant only if you are accessing the PPC from an IBM compatible PC To install simply COPY everything in the root or utils directory of the supplied diskette to any suitable directory on your hard disk and edit your AUTOEXEC BAT file to include that directory in the PATH lf your PC has floppy drives only you need only copy the KTERM EXE program to your working diskette The working diskette must have COMMAND COM on it otherwise you will not be able to shell out of KTERM Step 2 Connections With the PC PPC cable detailed in the Serial Ports and Cables chapter connect an ANSI compatible terminal or a PC to Port 1 of the PPC see the PPC Executive chapter for details and connect the PPC power unit Step 3 Enter the Executive Following power up the PPC will run through a quick power up test which is visible on the front panel LEDs after which the EXE LED remains flashing lf the EXE LED does not start flashing then the PPC has probably been previously configured to automatically execute a program see the Troubleshooting chapter on how to enter the Executive lf you are using a terminal press the ESC key several times if necessary If you are using an IBM compatible PC run the supplied KTERM EXE program by typing KTERM H The Executive menu see the PPC Executive chapter should now appear PPC74 Executive
166. n writeln portl NVRDBLK failed eeaddr memaddr blksize retcode PPC PASCAL 6 43 Comments and Compiler Options COMMENTS A comment within a PASCAL program may occur between any two reserved words numbers identifiers or special symbols A comment starts with a character or the character pair Unless the next character is a all characters are ignored until the next character or character pair If a was found then the compiler looks for a series of compiler options see below after which characters are skipped until a or is found For example j i 1 bump the loop count j i 1 bump the loop count L turn the listing on from now L turn the listing on from now COMPILER OPTIONS These one letter options that can be used to control the compilation process some of them can be used throughout your program while others can only appear at the start of the program For example C A this text can be anything turns off break checks and array index checks General Options These may appear anywhere in the program Option L Controls the listing of the program text and object code address by the compiler If L then a full listing is given If L then lines are only listed when an error is detected Default is L A compilation listing of an autoexec or an encrypted program is suppressed regardless of the setting of this option Option S Controls whether or not stack checks are mad
167. n for writing binary data 5 All 1 0 in the PPC is buffered If a program reads a few bytes of data from the input and then goes away to process the data any additional input data which arrives during the processing will not be lost provided the correct handshakes have been enabled These buffers are fully interrupt driven run in the background and are therefore transparent to PASCAL but they do result in smoother data flow and more efficient operation For full details of the buffering see the PPC Ports chapter Some of the Standard PASCAL file accessing constructs are meaningless in the PPC environment and these have therefore been deleted INPUT OUTPUT TEXT RESET REWRITE GET PUT EOF TS Because as described earlier PPC PASCAL files contain whatever printable or non printable data you want them to contain all file type declarations like filel FILE OF CHAR file2 FILE OF INTEGER file3 TEXT are not used It s possible to read or write chars integers floats etc but this is achieved by using the appropriate BREAD or BWRITE operations Only four filenames are allowed in PPC PASCAL and these correspond to the four PPC 1 0 ports PORT1 PORT2 PORT3 PORT4 and all four are already opened for both reading and writing when a program starts execution The above port names are internally predefined as constants of type TEXT and this allows the writing of port independent 1 0 procedures to which the port number can be passed as a param
168. n input queue 0 255 int ipqclear int port clears discards input queue int opqspace int port returns space in output queue 0 60 int opqcount int port returns of bytes in output queue 0 60 For a more detailed description see the similarly named functions in the PPC Pascal section 1 0 Port Configuration Functions You may never need to use these because the entire configuration of each PPC port can be configured from the Run Time Serial Port Configuration menu and this is how it is usually done These functions are needed only if your program needs to read and or modify the port settings during its operation or if you need to override the above settings The first of the following two functions enables your C program to configure a PPC port and the second allows the present configuration to be read back int setportcfg struct sp_t anyname configure port from sp t int getportcfg struct sp t anyname fillsin sp_t Both make use of the same structure which is defined in ppclib h as sp_t Note that with getportcfg you must fill in the port number getportcfg then fills in the rest C Reference 12 3 aa 1 0 Port Direct Handshake Control You may never need to use these because the handshake operation of each PPC port can be configured from the Executive Run Time Serial Port Configuration menu and this is how it is usually done These functions are needed typically only if your program nee
169. n the PPC s filing system See the KTERM chapter for full details of KTERM operation 9 Transfer PPC PC This function works only with the supplied KTERM EXE terminal emulator It will not work with any other terminal or terminal emulator program Pressing J when this item is highlighted transfers the currently selected program from the PPC to the PC At the PC the file is written either into the current directory or as directed by the environment variable KTERMFILES path PPC programs with the Pascal Basic or binary language attribute are written at the PC as PAS BAS or BIN files respectively See the KTERM chapter for full details of KTERM operation 10 Config amp diagnostics Pressing J when this item is highlighted enters a sub menu PEC Configuration diagnostics Cunt iy dunp upat hex dunp Serial Port tests Frinter con ig Executive Mode Port 1 confiy Set real time clock option Analuyue Puri tests option 3 6 The PPC Executive 10 1 Runtime port config Pressing J when this item is highlighted displays a screen which allows the power up defaults for all PPC port parameters to be easily configured PPCe4 run time serial port configuration HX handshake TX handshake baud tits stup XUN XUN cate ward parity bits ATS DTR XOFF CTS BSA XNFF Port 1 9600 8 nont 1 ON UN ON ON ON UN Port 2 META 8 even 1 ON ON ON UN ON ON Part 3 115200 5 odd 1 ON OM NFF aN ON OFF Port 4 38400 7 even UFE U
170. nalog digital converter ADCC read analog digital converter calibrated o 6 38 ADCGAIN set 100mV ELV gain ci do Be OE BS a as 6 38 DAC drive digital analog converter DACC drive digital analog converter calibrated 0 6 38 EXEC IMCS de Sets ia e la ida 6 39 ANEERD read analog subsystem calibration EEPROM ANEEWR write analog subsystem calibration EEPROM 6 39 DIN read TTL input 1 DINZ Sead TILANDUL F2 2 lt 6 2 dead aaa A 6 39 DOUT1 drive TTL output 1 DOUTZ A A fen a wae noche tk a E Mh asses 6 39 DG1 Parallel Digital l O Card Pascal functions ooa aaa o 6 40 PDIN read parallel digital inputs o ee 6 40 PDOUT write parallel digital outpuis 2 o oo o o 6 40 EEPROM non volatile access functions oaa a 6 41 NVWRITEC write a char 2 a a 6 42 NVREADG stead a Chal la daa rd es 6 42 NVWRITEl write an integer o oo oo o 6 42 NVREADI read an integer o o oo 6 42 NVWRBLK write a block 0 4 cdta e ace e e aba eel 6 43 NVRDBLK read a block 0 0 oo ee 6 43 Comments and Compiler Options 2 o o 6 44 OMIM ec stds Sith e Ae Akt AR Ao A sett A dost eed ot os o ce ho 6 44 GOMPIRER ORION S cie 2 soci arue da B couche e Gade tate Seb Pah esata a he og ia ey 6 44 General OO ONS 18s tes egal tao it da 6 44 Optimi a A A A AA Sic 6 44 ODIOM S Sayn a E a o
171. ndard library is what is provided in the PPC ROM The PPC specific extensions are additional The Hi Tech supplied libraries are not used for the PPC Step 3 PPC C Software Utilities Installation Create a directory to work in e g c ppc Copy all files from the c directory on the PPC Software Utilities diskette into it Read the read me file The C option requires KTERM EXE version 1 02 or later EXE dated 1 FEB 94 or later If you are an existing PPC user make sure you have an up to date version of KTERM Step 4 C Option installation The C Option is factory installed in the PPC ROM Its existence in your PPC can be confirmed by invoking the Config Dump menu item and selecting the output in ASCII to port 1 Existing PPCs without the C Option can be field upgraded Contact your PPC supplier for details Step 5 Reboot your PC This is necessary to make effective any changes to your autoexec bat file made by the compiler installation program These changes are usually limited to a adding the compiler path to your path and b adding several environment variables to your environment As is usual with programs which modify your autoexec bat file you should examine the changes in autoexec bat to make sure they have not affected something else Step 6 Create a program Using your favourite non document editor create the following program called hello c include ppclib h pragma psect text r_text pragma psect const r_const pr
172. ning in a window to a Windows 3 x application but the amount of text which can be pasted may be limited by the application s capabilities When running a DOS application such as KTERM in a window Windows waits for the application s screen contents to stop changing before it updates the window This has the side effect that during file transfer when KTERM updates the displayed byte count very rapidly the byte count shown in the Windows window appears stuck until the file transfer is finished Instead of KTERM it is possible to use the TERMINAL EXE program which is supplied free with Windows However it has poor performance is likely to lose data at speeds above 9600 baud even on a 486 33 and does not support file transfer with the PPC KTERM 1 5 aj aj Running KTERM over a modem link This is desirable for applications where the configuration of a remote PPC or a program resident on that PPC need to be modified remotely This is possible because if an autoexec program terminates the PPC returns to the Executive You must also write your PPC Pascal program so that it terminates when it receives a specific key or key sequence from Port 1 Alternatively you must instruct someone at the remote location to set the PPC into the Executive mode prior to your dial up Accessing the PPC via a modem is not difficult but there are the standard pitfalls when using modern modems which do automatic baud rate detection This
173. not process characters already stored somewhere Characters from the variable STRING are converted into a numeric value which is stored in the variable or R The integer NEXTPOS returns the offset of the first character after the number relative to the start of the variable STRING this allows successive invocations of VAL to read a series of numbers without requiring a preceeding forward scan to find the end of each number SUCCESS is returned as TRUE if the value converted successfully If FALSE NEXTPOS then holds the location of the error aS an offset from the start of the string variable which was given to VAL Normally STRING will be a string variable an array of char but other types can be used The rules which determine what constitutes a valid number and what terminates a number are as for the READ procedure The following examples show some of the various uses of VAL Assume that the array src contains the following characters where A represents white space AAA234A23 45AAA 2 56E8AA 2 56e08AAt 28AA 289aaaa23k then the following program code will act as commented on the right var src array 1 100 of char suc boolean ivalue npos integer rvalue real val src ivalue npos suc skips initial 3 spaces and returns ivalue 234 val src 1 ivalue npos suc same as above val src 4 ivalue npos suc same as above PPC PASCAL 6 31 aj aj val src 4 rvalue npos suc reads 1st as a real
174. ns 6 7 8 11 This has the effect of wiring the CTS DSR inputs to READY HIGH levels and it also ties the CDI input to a HIGH level These signals are unused on an RS422 485 port but incorrect levels on CTS or DSR can prevent data transmission from that port Observe standard anti static precautions when working with any unprotected circuitry This means working on an anti static conductive mat and wearing a wrist strap which is connected to the mat Avoid short circuiting the RTC battery If this has been shorted even momentarily you must run the Reset R command in the RTC Configuration in the PPC Executive and of course re enter the correct date and time For above reasons do not store the PPC E Eurocard version in a metallised conductive bag Some such bags will run the battery down very quickly and can even short circuit it resulting in a theoretical fire hazard PPC E DIN41612 connections The PPC E uses a standard Eurocard 64 way 2 row DIN41612 connector In most applications this product will plug into a custom backplane However the DIN41612 pin connections on this connector are arranged so that it is possible to make up an IDC insulation displacement cable terminating in four DB9 male IDC connectors as shown below jj B P2 PPC E component side view SS BG BG With the above cable arrangement the pin connections of the DB9 connectors are identical to those of the standard PPC 4 produ
175. nt line Note that the line is placed into the editing buffer and can be recalled into the text by use of the CTRL U restore line command The deleted line will be overwritten when the user next makes a change to any line BACKSPACE or CTRL H DEL not available on all ANSI terminals CTRL 0 T CTRL T Delete from the cursor to the beginning of the last next word The characters that constitute the boundaries between are given under the Word left right command above Wraparound operates CTRL Q DEL CTRL Q Y The editor implements a simple block buffer scheme where a deleted block is retained in a block buffer The block buffer is located in the memory area which remains free between the end of the file being edited and the end of memory Therefore the larger a file you are editing the smaller the block buffer will be No facilities are currently implemented for reading or writing blocks to the PPC filespace The only method of merging separate files etc is to transfer them to a PC with KTERM perform the desired operations with a non document editor and transfer the merged file back to the PPC Mark start end of block CTRL KB CTRL K K Move block Copy block Delete block Paste block Place the block markers A marker will be positioned at the cursor position The markers are lost if the line containing the marker is edited CTRL K V Delete the currently marked block from the text and place in the block buffer th
176. nt outputs a text report of the PPC port configuration and other information to the selected output port The report is in the following form PPC 4 run time serial port configuration RX handshake TX handshake baud bits stop XON XON rate word parity bits RTS DTR XOFF CTS DSR XOFF Port 1 9600 8 none 1 ON ON ON ON ON ON Port 2 9600 8 none 1 ON ON ON ON ON ON Port 3 115200 8 none 1 ON ON OFF ON ON OFF Port 4 38400 8 none 1 ON ON ON ON ON ON PPC 4 Port 1 Executive Mode baud rate config Port 1 9600 8 none 1 OFF OFF ON ON OFF ON ROM version 1 02 01 JAN 93 Serial 1999 Options none The ASCII output mode outputs the report to an ASCII printer Almost any printer can be used The Postscript output mode requires any Postscript device to be connected to the selected port The HPGL output mode works with most HPGL compatible plotters and other output devices regardless of paper size The text of the report is plotted with Pen 1 which must be present The PPC Executive 3 7 10 3 Input hex dump This function is very useful for determining exactly what characters are present in a data stream When this function is selected with A a menu of PPC ports appears Pressing at this point enters a mode in which any data which arrives at the specified port is displayed using a combination of hex and ASCII characters The output is in the following form 000000 OD OA 50 50 43 2F 34 20 72 75 6E 2D 74 69 6D 65 PPC 4 run time 000010 2
177. nteger bit wise XOR FUNCTION XOR VALUE1 VALUE2 INTEGER INTEGER This performs a bit wise XOR of the 16 bits constituting each of the two integers and returns the integer result _CPL integer bit wise complement FUNCTION _CPL VALUE INTEGER INTEGER This inverts the bits in the integer VALUE and returns the integer result _SHL integer shift left FUNCTION _SHL VALUE PLACES INTEGER INTEGER This shifts VALUE left by PLACES bit positions with zero fill and returns the integer result Any carry out from the top bit bit 15 is discarded This function is faster than the alternative shifting left by multiplying by a power of two Only the four least significant bits of PLACES are used limiting it to 0 15 _SHR integer shift right FUNCTION _SHR VALUE PLACES INTEGER INTEGER 6 34 PPC PASCAL This shifts VALUE right by PLACES bit positions with zero fill and returns the integer result Any carry out from the lowest bit bit 0 is discarded This function is faster than the alternative shifting right by dividing by a power of two Only the four least significant bits of PLACES are used limiting it to 0 15 ROL integer rotate left FUNCTION _ROL VALUE PLACES INTEGER INTEGER This rotates VALUE left by PLACES bit positions and returns the integer result Any carry from bit 15 is fed back into bit 0 Only the four least significant bits of PLACES are used limiting it to 0 15 _ROR integer rotate right FUN
178. ny people do and the upgrade can be loaded with yet more bugs You cannot do this with a datacomms product however and careful programming and testing is the only answer Fortunately most datacomms programs especially those on the PPC will be quite small and easy to thoroughly test Robust reading of input data This is one of the most important requirements in a datacomms product Garbage can appear at the input due to a variety of reasons which can include the powering up down of connected equipment and the plugging unplugging of cables The actual method used depends on the type of data being read Character data Read input data 1 char at a time discarding everything until a valid character appears In packet oriented protocols look for a start of packet character Next load everything into an array of char buffer until one of the following happens an end of packet char is received or the buffer is about to overflow const startpkt 16 endpkt 02 inport port2 var c char i integer buffer array 1 100 of char repeat bread inport c read input and discard until start char appears until c startpkt 1 1 repeat bread inport c read a char buffer i c put it into the buffer i 1 1 until c endpacket or i gt 100 and repeat ASCII numbers The safest way of reading these is by reading input data 1 char at a time discarding everything until a valid numeric ch
179. oa a e 5 2 EXOIOSSIONS i dr Boe c uta a Bok eee ute ae a ete Herd its Rae daa ES 5 2 Statements cl Sheds eG Whe ee he ie hes ela dah Ge ae EH oD 5 2 Program nai icra ih e ee foe Sad Been Me es 5 2 BASIC FUNCHONSS a fais ie Sch gash anh tag A e os yada ae ds 5 4 PD A oi lei wt ceed ch Rk Atri Se My Boe Gesell Cet RN AE 5 4 A AD SPAS ech See deed a E ene Se UB Seb pte fe Ne bt Soo 5 4 Ce a eee as oe Re Oe e a a e ee eee meee ee 5 4 WGE arid oh desire ed we end ne Se ead gene e Lh oe ia ia hha ns 5 4 A ERE 5 4 A A A O YD A 5 4 BASI OM Sie e rr E e A AREA 5 5 FTE AeA MP Rate de det Han te net te ich te tera Be Ns tee te AR ata 5 5 EERME e of veda Sk tocar apse tool shoe nonin Hei FCG dated AN 5 5 A Ut he te wtone ah atte O 5 5 Fe RM tartrate an A O Se Le cs ete ep tal 5 5 COTO 2 AS ie he A ar ag EN tanec kage Gh AN sick sere aerate Ae 5 6 GOSUB RETURN A ato Ato ch fata uate dl Site ease Wore IR O abe io ag le Ati a 5 6 FOR NE 04 hte sh nea aa theses Sicko Sore hae BS Soha vas OR a AeA Ot Mak rit O 5 6 A A A Soaks Soy antes Sede DEL de ates tee AAR de isk es 5 6 INUIT teste Sts IA og it thee Bot A Me NS dete A oie 5 7 A IE Renta Seta ach aspera tes Acad a Rule AD hare feeb wae Ree a 5 7 DIERON nt Sd A dl e US lA a 5 8 AAA IAN A E EE ands ale 5 8 A E A LO 5 8 A A A EE BALET ge Sa gh 5 8 AA A ES eR AE Ne a EN 5 5 8 AR eM Seek eget Aka Nl te ake E cca SM A et ee 5 8 LOAD ahi ob Antone and Ye Noaptea ake seo da dl of ht a yk a Ned
180. ocation PPC PASCAL provides a set of heap management routines Freed memory is re used but no garbage collection is provided These functions should be used with care and to prevent the heap potentially becoming full as a result of fragmentation NEW and DISPOSE should always be used in pairs this will prevent any fragmentation NEW PROCEDURE NEW VAR V The procedure NEW P allocates space for a dynamic variable The variable P is a pointer variable and after NEW P has been executed P contains the address of the newly allocated dynamic variable The type of the dynamic variable is the same as the type of the pointer variable P and this can be of any type To access the dynamic variable P is used To re allocate space used for dynamic variables use the procedure DISPOSE or alternatively MARK and RELEASE see below If there is no memory left a runtime error Out of RAM will be generated There is no method of checking whether NEW will succeed but if MEMAVAIL is greater than SIZE V then it will definitely succeed If it is less then NEW will probably fail but not if there is a large enough hole in the heap from a previous DISPOSE See the note about fragmentation at the top of this page DISPOSE PROCEDURE DISPOSE VAR V This procedure frees the memory used by the variable pointed to be V V must be a pointer variable which points to a variable created using the NEW procedure see above After the call to DISPOSE V should be made
181. ograms can be designated autoexec and execute automaticalloy at every power up FILING SYSTEM PPC Overview 1 1 The Front Panel COM ME m Tl PGM HEE Mmm Rl EDT HE Mmm 1X2 CER ME mm RX rR ES NPR M RS USR TX Xi E R4 PPC PROGRAMMABLE PROTOCOL CONVERTER co i ee EDT CER i z s USR KSI E PUR EXE L rst J RESET 3 PA PPC ies he The PPC has three front panel switches SW1 SW2 amp SW3 which are readable from within LU BASIC PASCAL and C programs They also perform the following functions SW2 SW3 PPC Reset Depressing SW2 and SW3 simultaneously for approximately 1 second causes the PPC to be reset This is equivalent to interrupting power The reset state is indicated by the RST LED SW1 Entry into the Executive If SW1 is depressed when the PPC exits from reset the PPC enters the Executive even if it had been previously configured to autoexec a program at power up The Executive is a menu driven system for PPC configuration and for editing user programs See the Executive chapter for details LED Indicators The ten LED indicators on the main LED bar display have the following functions COM A compilation is in progress PASCAL only PGM A program PASCAL C or BASIC is running EDT The PPC editor is running CER A compilat
182. om the PPC filing system For example to delete the program saved with the above SAVE command KILL PROGI The main purpose of this command is to make room for a new program to be SAVEd if you have already filled up the PPC file directory Exiting BASIC to delete a file would cause the BASIC program which is currently in memory to be lost BYE or SYSTEM Either of the above commands returns to the PPC EXECUTIVE Any program currently in memory which has not been SAVEd is lost 5 8 BASIC Programming Examples The following program is equivalent to the translation table based example in the Pascal Programming Examples section lt translates characters received on Port 2 and transmits the output on Port 3 10 FOR 1 0 TO 255 20 6 1 1 30 NEXT 1 40 65 122 41 0 63 42 0 7 42 43 35 156 44 135 102 45 136 103 46 137 116 47 138 107 48 139 121 49 140 109 50 REDIR 3 60 C WGET 2 70 C C 80 PRINT CHR C 90 GOTO 60 Initialise translation table for 1 1 translation Set up any special character translations All output will go to Port 3 Get char from Port 2 Translate it through the table Output it Repeat forever The above program like all PPC PASCAL programs will terminate execution if a control c char 3 decimal is received on Port 1 unless the program is running in autoexec mode Speed tip For maximum execution speed the above program can be equivalently written a
183. omething which most PASCAL compilers will not allow Also missing from the PPC is the now irrelevant convention in some PASCALs that there should be an initial blank line EOLN TRUE when reading with READLN The following examples of file 1 0 briefly demonstrate how anything can be read from or written to a file simply by choosing the appropriate input or output statement var n integer c char read port2 n expects one integer in ASCII text form e g 12347 readIn port2 n as above but expects an end of line CR after the number bread port2 n as above but reads the two binary bytes that constitute an integer bread port2 c reads just one byte the most useful PPC input function 6 8 PPC PASCAL n 12347 c A s write port2 n outputs the integer in ASCII text form e g 12347 writeln port2 n as above but follows it with a CRLF character pair bwrite port2 n outputs the integer as two binary bytes 3Bh 30h in this case bwrite port2 c outputs just one byte 41h in this case very useful For full details of the above file I O functions see the READ WRITE etc information in the Procedures and Functions section RECORDs The implementation of RECORDs structured variables composed of a number of constituents called fields within PPC PASCAL is as Standard Pascal except that field identifiers share the same symbol table space as record names and other identifiers meaning that a declaration TYPE ListO
184. onnector inputs on the PC are both HIGH Soo 8 Bod 2 PC lt gt PPC cable The following cable is suitable for use between an IBM compatible PC and the PPC The connections actually required will depend on the type of communication taking place but this example shows all the possible connections for an application involving full duplex binary data with full duplex hardware handshakes The cable will also be suitable if XON XOFF handshaking is used but note that binary data cannot be sent in the same direction as any XON XOFF characters PC 25 way PPC 9 way 447 GND GROUND SHIELD GND 5 2 TX A RX 2 3 RX A DE lt 3 4 RTS HANDSHAKE CTS 8 5 CTS HANDSHAKE RTS 7 20 DIR OPTIONAL 1 DSR 6 6 DSR OPTIONAL 2 DIR 4 The connections named optional above perform no useful function except that OPTIONAL 2 supplies an RS 232 HIGH level to the PC s DSR input as required by most PCs if transmitting data with BIOS functions PPC printer plotter cable The following cable is suitable for driving most types of DTE output devices and supports both hardware and XON XOFF handshakes PPC 9 way PRINTER PLOTTER 25 way A aii GROUND SHIELD ER 3 p DAA EOU eG a XON XOFF ag FIXED HIGH LEVEL Reeve 8 CTS RTS 4 4 DiR FIXED HIGH LEVEL Jonee bea HARDWARE HANDSHAKE sae aie The un named connections do not usually serve any purpose except to supply an RS 232 HIGH level to the device s
185. ons These are special functions and procedures which support the special features of the PPC and they are all documented in the PPC PASCAL Syntax and Semantics section later in this chapter 2 Compiler options These are commands embedded in the program which control compiler operation See the Comments and Compiler Options section 3 Unimplemented standard PASCAL features These are mainly in the I O area where the standard PASCAL file variables and functions e g EOF etc are irrelevant in the PPC s stream 1 0 environment Unless otherwise Stated the implementation of PPC PASCAL is as specified in the Pascal User Manual and Report Second Edition Jensen Wirth The PPC is an 1 0 intensive device and PPC PASCAL programmers must understand how the 1 0 functions work In particular users with previous PASCAL experience should study the Programming Examples section which contains examples of reading character oriented data Compiler Listing The compiler generates a listing of the form 8906 11 for x 0 to 10 do 8906 12 begin 8906 13 y X 4 8906 14 Z X y E text of source line source line number hex address of generated code The source text is listed without modification with any tabs expanded with the standard PPC tab expansion of 4 character tab stops The address is a 16 bit hexadecimal address and is relevant only if runtime errors occur when the error message reports the approximate address at which the run
186. ontains the addresses of all ROM based functions Unlike other environments you do not link your program to any library as such The only exception to this is the ppcextra lib library which contains some rarely used C functions which were not included in the PPC ROM due to space considerations C Reference 12 1 C Extensions All functions which are implemented in the PPC C system are defined in the ppclib h file Nearly all of these are contained in the ROM based runtime library This runtime library also contains Jong and float versions of all relevant functions including fprintf and sscanf so the usual huge program size penalty involved in using floats is avoided A few rarely used functions e g malloc are in a separate library ppcextra lib which you must link to your program if you need them ppclib h is the only file which you need to include in your program Do not include stdio h conio h or any other of the h files supplied with the Hi Tech compiler This section documents all PPC specific functions i e those which are not part of ANSI C It also documents all functions which the PPC implements differently from the ANSI C standard Please refer to the Hi Tech manual or a C reference book for details of all remaining PPC C functions their prototypes are listed in the ppclib h file Because many of the PPC specific extensions are similar or identical to those provided in PPC Pascal you are advised to
187. or the mark has been lost i e the line containing the mark has been edited Block marks reversed Produced after any block operation if the start of the block occurs after the end Invalid destination Produced after a MOVE BLOCK or COPY BLOCK and indicates that the destination cursor lies between the start and end of the block inclusive No block in buffer Produced after a PASTE BLOCK operation and is self explanatory Marker lost Produced after a RETURN TO POSITION command and indicates that the position marker has not been placed or has been lost No such line Produced after the GO TO LINE command and indicates that the line number given is greater than the number of lines in the file The Editor 4 7 Editor limits The maximum line length is 255 characters Note that the cursor column number may exceed 255 due to tab and control characters in which case the column number displayed on the status line remains at 255 The maximum file size is limited by available memory which is approximately 29 000 bytes It is perfectly possible to edit a file which at any particular moment is too large to be saved Whenever a file s size is in this range al is displayed after the file size The maximum number of lines in the file is limited only by available memory but note that the line number display on the status line is only of four digits due to space considerations and the GO TO LINE command can only reach line 999
188. ost PPC programs will have in common it runs forever and unlike a program written e g for a personal computer it never terminates More programming examples are given at the end of this Section How to create a PPC BASIC program A PPC BASIC program can be created either by entering PPC BASIC the Interactive Basic option on the main EXECUTIVE menu and interactively typing it in or by using the PPC text editor If the editor is used an empty program of the desired name and language Basic must first be created with the Create Program option A BASIC program can also be created by creating it first on a PC with an editor and then transferring it to the PPC A BAS file will when transferred to the PPC appear as a Basic file in the filing system How to execute run a PPC BASIC program If you enter BASIC from the Executive you must LOAD the required program then type RUN You may use the DIR command to see which BASIC programs are in the filespace Alternatively when you have finished the program and it is working as it should you can designate it to be an autoexec program see the Executive chapter and it will then execute automatically whenever the PPC is powered up PPC BASIC language description Below is a full list of PPC BASIC language features Note that PPC BASIC is case sensitive and all parts of the program must be UPPERCASE The only exceptions within a program are quoted strings e g ABCD in INPUT
189. ount of data generated and the space for data is reduced by the amount of code generated During compilation code is placed into memory from bottom upwards and static data is allocated from top downwards When the two meet Somewhere in the middle you have run out of memory The following diagram illustrates the memory allocation EIA eed Daa A data top FEFF hex STATIC STATIC DATA DATA CODE CEILING 26208 bytes ese e eee beee dee eyes sirenos boii Address EF60 hex FREE RAM run time free memory HEAP CODE CODE A has code base 8900 hex COMPILATION TIME RUN TIME Static data is allocated during compilation from top down and can extend a mostall the way down to top of code What is left in between will be the run time free memory and the compiler will always leave at least 512 bytes spare As an example in a program which contains var a array 1 10000 of integer this uses 20 000 bytes there will be less than 10 000 bytes left for all the code In addition there is a code ceiling of 26208 bytes which corresponds to a hex address the value displayed during compilation of EF60 This ceiling is imposed by implementation factors beyond the scope of this manual Static data represents all variables declared with VAR statements in the outermost block of a program and such variables are always accessible from everywhere in the program The heap is memory used for dynamically allocated variables e those allo
190. plemented to return the tota of the number of bytes in the 64 byte output queue p us the number of bytes held in the UART transmit circuitry This ensures that when the value returned is zero all data generated by your program has been transmitted out of the PPC However this works perfectly only on ports 3 and 4 On ports 1 and 2 a return value below 2 is ambiguous and means the following value 1 never returned value 0 there are 0 or 1 bytes still in the UART Therefore on ports 1 2 detection of everything sent out must be done with a timer by waiting until the OPACOUNT value falls below 2 and then waiting for at least 2 character periods After this function has been invoked the number of bytes in the output queue may decrease as a result of data being output but it can never increase except by being filled by your program SETRTC set real time clock FUNCTION SETRTC VAR T RTCTYPE INTEGER This function sets the PPC real time clock from date and time values held in a record which contains the following members tm sec integer seconds after the minute 0 59 tm min integer minutes after the hour 0 59 tm_hour integer hours since midnight 0 23 tm mday integer day of the month 0 30 tm mon integer months since January 0 11 tm year integer years since 1900 50 149 tm_wday integer days since Sunday 0 6 The following example loads the clock with 18 48 55 Sunday 10th May 2002 var anyname rtctype g
191. presenting the ordinal number of the value of X within the set defining the type of X ORD a returns 97 ORD returns 64 If X is of type integer then ORD X X this should normally be avoided CHR FUNCTION CHR X INTEGER CHAR X must be of type integer CHR returns a character value corresponding to the ASCII value of X 6 20 PPC PASCAL CHR 49 returns 1 CHR 91 returns Arithmetic Functions In all the functions within this sub section the parameter X must be of type real or integer unless specified otherwise ABS FUNCTION ABS X real or integer same type as input Returns the absolute value of X e g ABS 4 5 gives 4 5 The result is of the same type as X SQR FUNCTION SQR X real or integer same type as input Returns the value X X i e the square of X The result is of the same type as X SQRT FUNCTION SQRT X real or integer REAL Returns the square root of X The returned value is always of type real A Maths Call Error is generated if the argument X is negative this error can be disabled with the O compiler option FRAC FUNCTION FRAC X real or integer REAL Returns the fractional part of X FRAC X X ENTIER X As with ENTIER this function is useful for writing many fast mathematical routines Examples FRAC 1 5 returns 0 5 FRAC 12 56 returns 0 44 SIN FUNCTION SIN X real or integer REAL Returns the sine of X where X is in radians The result is always of type real cos
192. program data memory area currently 8900 hex 35072 decimal This helps to prevent some errors because in any functioning program only data stored in PASCAL data structures should be written to the EEPROM Note that since the source address will normally be above 32767 it will be represented by a negative integer The following example program will write the second half of a 400 byte array into the EEPROM at addresses 1000 1199 var buffer array 1 400 of char memaddr eeaddr blksize retcode integer memaddr addr buffer 201 eeaddr 1000 blksize 200 retcode nvwrb1k memaddr eeaddr b1ksize if retcode lt gt 0 then writeln portl NVWRBLK failed memaddr eeaddr blksize retcode NVRDBLK read a block FUNCTION NVRDBLK EEPROMADDR DEST BYTES INTEGER INTEGER This function is the opposite of NVWRBLK It reads a block up to 2000 bytes in length from the EEPROM to any PASCAL data structure The returned error codes are as per NVWRBLK To trap some errors this function will refuse to write the data into memory whose address is below PASCAL code data areas The following example program will fill the second half of a 400 byte array from the EEPROM addresses 1000 1199 which were written in the NVWRBLK example program var buffer array 1 400 of char memaddr eeaddr blksize retcode integer memaddr addr buffer 201 eeaddr 1000 blksize 200 retcode nvrdblk eeaddr memaddr blksize if retcode lt gt 0 the
193. put AIN1 or AIN2 A TTL HIGH level is returned as TRUE DOUT1 drive TTL output 1 DOUT2 drive TTL output 2 PROCEDURE DOUT1 ONOFF BOOLEAN PROCEDURE DOUT2 ONOFF BOOLEAN The Boolean value supplied to this procedure controls the state of the DOUT1 or DOUT2 output A TRUE value sets it high 5V and a FALSE value sets it low OV PPC PASCAL 6 39 DG1 Parallel Digital 1 0 Card Pascal functions These functions are available only on a PPC fitted with the DG1 option the Parallel Digital 1 0 Card This card offers 16 TTL level schmitt inputs and 16 high current open collector outputs PDIN read parallel digital inputs FUNCTION PDIN INTEGER This function returns the states of the 16 inputs in the corresponding 16 bits of the 16 bit integer For example if the current states of the 16 input port bits are 0001 0010 0011 1111 then this function will return the value 123F hex 4671 decimal in the integer variable If the most significant leftmost input is high the returned integer will be negative PDOUT write parallel digital outputs PROCEDURE PDOUT VALUE INTEGER This procedure outputs the 16 bits of the integer VALUE to the corresponding output port bits The example pdout 123f will output the following bit pattern on the 16 outputs 0001 0010 0011 1111 With both above functions the most significant bit of the integer corresponds to bit 15 of the input or output port The least significant b
194. r array 1 20 of char substistr array 1 20 of char procedure search c char Procedure which accepts a char and if it matches the first char of the search string it gets more chars amp sees if they match etc var i j integer match boolean begin if c searchstr 1 then begin check 1st char match 1 1 match false repeat loop here while input matches the search string bread inport c i itl 6 54 PPC PASCAL if c searchstr i and searchstr i 1 0 then match true until c lt gt searchstr i or match if match then begin output the substitute string up to a 0 Jenks while substistr j lt gt 0 do begin bwrite outport substistr j j j 1 end end else begin output the matched part of the search string for j 1 to i 1 do bwrite outport searchstr j search c and recursively output the non matching char end end else begin bwrite outport c end end search The main program begin init searchstr Hello 0 initialise search string init substistr How are you 0 initialise substitute string inport portl outport portl repeat bread inport ch search ch until false end Every string search replace algorithm suffers from one problem if the input data stream ends and its last few characters just happened to be the start of a string which is to be replaced the system will hang until the rest of the string has a
195. r code the port may have been only partly initialised and its status is therefore undefined When a program is running under the Executive i e with Compile and Run initialising Port 1 has no effect but with a no error errorcode Only autoexec programs may initialise Port 1 This is done to enable you to test a program using Compile and Run with KTERM running at e g 38400 baud even if that program initialises Port 1 to say 9600 baud READPORT get serial port configuration FUNCTION READPORT VAR S SETPORTTYPE INTEGER This function is the opposite of SETPORT and allows a port s current configuration to be read It uses the same record as SETPORT You can use READPORT to fill in the record with the port s current configuration modify a part of it and re initialise the port with SETPORT The following example shows how you can use READPORT amp SETPORT to change only the handshakes var anyname setporttype retcode integer anyname sppc_port port3 specify the port whose config to read retcode readport anyname get the current port3 config with anyname do begin rx_rts h false disable RX RTS handshake rx dtr h true enable RX DTR handshake rx_x_hs false disable RX XON XOFF handshake end retcode setport anyname re initialise the port SETHSK control handshake outputs FUNCTION SETHSK VAR S SETHSKTYPE INTEGER This sets the states of a port s output handshakes according to
196. range 32767 to 32767 A positive overvoltage is returned as 32767 and a negative overvoltage is returned as 32767 The temperature channel 9 would be used for temperature compensation only and the precise temperature does not need to be known However it can be converted to K by dividing by 81 92 The ADC function returns a raw uncalibrated analog digital converter reading which can have a scale error of up to 5 of full scale The zero error is within 3LSBs however The input voltage range of 100mV 1V is guaranteed to be accommodated It is slightly faster than ADCC The ADCC function returns a highly accurate calibrated value The calibration is transparent but you can see the functions ANEERD and ANEEWR for details of how it is done When using ADCC to read in current loop mode it returns a calibrated value in the range of 6553 32767 corresponding to a transducer current in the range 4 20mA If you require the transducer s zero current 4mA to return a zero reading you must remove the 4mA offset in your software ADCGAIN set 100mV 1V gain PROCEDURE ADCGAIN GAIN INTEGER This sets the gain for all subsequent readings for channels 1 8 in voltage mode The permitted values of GAIN are 1 for 1V range or 10 for 100mV range Other values have no effect The current gain setting is ignored when reading in 4 20mA current mode DAC drive digital analog converter DACC drive digital analog conver
197. rate corrections are stored and automatically applied to zero and scale errors in all voltage measurements 4 20mA current loop measurements and DAC outputs All component tolerances are thus adjusted out in a manner which is transparent to the PPC programmer The initial factory calibration is 0 02 of full scale reading Temperature effects are not calibrated out but are typically within 100ppm C Special build options are possible with lower TCs The calibration EEPROM is accessible from the PPC with PPC PASCAL commands ANEERD ANEEWR and its contents can be modified if necessary Approximately 40 16 bit integer locations are free for other user storage this is For voltage inputs two functions are available calibrated ADCC and uncalibrated ADC The latter returns the raw uncorrected ADC reading and is therefore slightly faster Similar functions are provided for the output Installation The Analog Subsystem is normally factory installed in the PPC A field upgrade is possible and involves a PPC ROM change and a larger power supply unit Protection The analog inputs are protected against overvoltage to 30V Isolation The analog side is isolated from the PPC side with components that are rated at 500V DC or higher and all PCB clearances support this also Note however that the 25 way D connector which is used for all 1 0 cannot be properly specified at more than 50V DC although it can withstand much more The isolation canno
198. re not provided in the ROM based runtime library If you need to use any of these you need to add ppeextra lib to the end of the linker command line qsort asctime sinh strdup malloc ctime cosh bsearch calloc gmt ime tanh free localtime brk time_zone sbrk When ppcextra lib is added to the linker command line only those modules containing the functions which are actually used by your program are added to your program The increase in program size is usually therefore small Checking of printf type Function Parameters The following C compiler pragma statements in ppclib h enable very useful compilation time checking of the corresponding functions pragma printf_check sprintf pragma printf_check vsprintf pragma printf_check fprintf pragma printf_check vfprintf For example the following very common type of error is detected fprintf portl a d b d c d a b c d one extra parameter For this to work the compiler must be invoked with a warning level of 1 w 1 on the compiler command line or lower Performance Hints The following general suggestions apply to C programs generally and are not in any particular order of importance They are relevant only if you find you need the highest possible performance otherwise you can safely ignore them all Use statically allocated variables instead of local i e stack based variables Global variables are much faster to access and produce a program
199. re very fast although the software overhead involved in the function call means they are not as fast as e g reading data from an array in RAM The functions NVWRITEC and NVWRITEI only perform a pre read of the location and an actual write of the EEPROM takes place only if the existing contents of the location differs from the value being written Depending on the application this can prolong the typical life of the EEPROM but the main reason for it is to prevent damage if a runaway program loops on a constant EEPROM address while writing a constant value to it This pre read scheme means that the actual execution of an EEPROM write operation can vary greatly down to a few of the 5ms typical figure The block function NVWRBLK does not do a pre read and must be used with even greater care Each of the EEPROM functions returns an integer error code A non zero value indicates an error 1 Invalid EEPROM address return code 1 Note that an attempt to read or write e g a 500 byte block starting at address 1700 will also return an error because the block must be entirely contained within the 2000 byte area Similarly the highest address for integer reads writes NVWRITE or NVREADI is 1998 not 1999 2 An EEPROM write error return code 2 This should never occur unless the EEPROM device is faulty or your program has destroyed one or more locations in it PPC PASCAL 6 41 All the write functions perform a verify after the w
200. recise to the full 16 bits The formula for the temperature is subject to change lf your PPC does not contain the analog subsystem option a message to that effect appears 11 Reboot the PPC Pressing when this item is highlighted has the equivalent effect to powering down the PPC If you are running KTERM with a command line specified baud rate other than 9600 baud you will need to exit KTERM with alt x wait until the EXE LED starts flashing and then re invoke it This is because following a reboot Port 1 defaults to 9600 baud and is unaware of KTERM s higher baud rate The PPC Executive 3 9 PPC EDITOR The PPC Editor is a full screen interactive editor which allows programs of any size up to the PPC memory limit to be edited in the PPC with an ANSI dumb terminal or with KTERM The editor uses mainly Wordstar compatible commands and users familiar with Wordstar will feel at home right away However most editors and word processors available today share common features such as block delete copy paste etc and you need only to learn a few keystrokes The editor is fully integrated into the PPC environment allowing a rapid edit compile run program development cycle It can edit both BASIC and PASCAL programs It is a non document editor i e it does not perform any text justification Alternatively the PPC editor can be bypassed altogether and files may be created on a PC with your favourite non document ed
201. rief power up test the program will run and the text output will appear on your KTERM terminal connected to Port 1 PPC firmware v1 07 or higher use Compile and Run to run the program or as above The supplied makefile contains two targets hello bin and test bin The latter is a larger C program which tests all the PPC specific C extensions and its source test c is a very useful reference for writing comms programs for the PPC Creating larger programs The procedure is the same You need to edit the supplied makefile and add a new target to it A new linkfile must also be created Larger programs should be split up into several modules These are normally compiled separately and then linked together This is good programming practice From this point on C programming on the PPC is just like C programming on a PC There are differences of course but these are mainly in the areas of input output where the PPC differs greatly from the very rudimentary comms facilities which a PC provides The next section is a reference covering all PPC specific C extensions and differences C Introduction 11 3 C Reference This section covers the C Option for the PPC It discusses PPC specific C extensions and other features of the PPC C programming environment which a C programmer needs to know about The memory map This is very similar to that used in PPC Pascal in that the runtime library is ROM resident and the binary program executes
202. rite so provided that the return code is zero there is normally no need to read back the EEPROM to ensure the data was correctly written An EEPROM has great advantages over the battery backed CMOS RAM non volatile storage schemes used by other equipment manufacturers extremely high reliability and long life It is almost impossible to corrupt the data stored in an EEPROM other than by modifying it with the functions provided The storage life is guaranteed at 10 years and the predicted typical figure at 25 C is gt 100 years A power loss during an EEPROM write operation will cause the write operation to be terminated and could even result in loss of data at addresses other than those being written at the time of the power loss NVWRITEC write a char FUNCTION NVWRITEC EEPROMADDR INTEGER C CHAR INTEGER This function stores a character at a specified address in the 2000 byte EEPROM non volatile area Valid addresses are 0 1999 decimal Execution time is 10ms max 5ms typ The following example reads chars from Port 3 discards everything up to a and then loads the next 20 chars into the non volatile area starting at address 1500 var inputchar char chrcount nvaddress retcode integer repeat bread port3 inputchar until inputchar discard chars until nvaddress 1500 initial EEPROM address chrcount 20 process 20 more chars repeat bread port3 inputchar retcode nvwritec nvaddress
203. rrived The only solution is a timeout Performance hints The following general suggestions apply to PPC PASCAL programs and are not in any particular order of importance Use global variables instead of local variables Global variables are faster to access and produce a more compact program Use inline code rather than function or procedure calls Avoid unnecessary copying of data from one buffer to another Pass all large variables e g arrays by address i e make them a VAR rather than by value For fast 1 0 use BREAD and BWRITE They are faster than READ and WRITE When outputting an array use the form bwrite port arrayname to output the whole array bwrite port arrayname n to output the first n bytes only The above constructs are much faster than reading or writing single characters from within a loop PPC PASCAL 6 55 Program too large In the unlikely case of symbol table overflow the solution is to use shorter symbol names or use fewer symbols In the equally unlikely case that your program is too large to be stored in the PPC s filing system a MS DOS program called KPACK EXE is available which processes the Pascal source file and considerably reduces its size lt does this by removing comments blank lines replacing long variable names with single and double letter names and other techniques The result is still a Pascal source file albeit not a very readable one which can be compiled and run on th
204. s 5 GOTO 10 6 PRINT CHR WGET C GOT06 10 above lines 10 50 go here 60 GOTO 6 The above version is faster partly because the main program loop is on a Single line and partly because it is near the start of the program The fewer lines a program has the less work the interpreter has to do Also the nearer a loop is to the start of a program the fewer lines the interpreter has to search through to find a line number specified by GOTO or GOSUB However whatever you do to speed up interpreted Basic programs compiled Pascal or C will generally be 10 100 times faster BASIC 5 9 PPC PASCAL What is PPC PASCAL PASCAL is a powerful high level programming language developed and standardised in the 1970s The PPC PASCAL compiler provides a close implementation of ISO standard PASCAL and is suitable for writing all programs ranging from the simplest to the most sophisticated Many extra functions and procedures not found in standard PASCAL are included to reflect the special PPC environment and applications PPC PASCAL is a compiled language The compiler generates machine code directly with no intermediate stages The code is very efficient and even complex programs can achieve sustained data rates up to 115 200 baud Even the most complex protocols found in the RS 232 environment can usually be implemented at full speed Example The following simple PPC PASCAL program will read characters from PPC port 3 con
205. s in case this is not self evident from the program s name If the program is binary a 16 line hex dump is displayed of the first 256 bytes of the binary image 6 2 Print program This function generates a hard copy of your program on a printer attached to any PPC port When this function is selected with A a menu of PPC output ports appears This is followed by a menu of output devices currently supported types are ASCII and Postscript 3 4 The PPC Executive aa aj Selecting ASCH outputs the currently selected program to a printer connected to the selected output port Tabs in the program are expanded to spaces on 4 character tab stops and since the only control characters used are CRLFs any ASCII printer will work The printer can be initialised with a user definable string specified in the Printer Config function see 10 5 the default initialisation is for a HP Laserjet and selects a 16 6cpi line printer font Selecting Postscript is as for ASCII except that the text is converted to Postscript and a Postscript printer must therefore be connected to the selected port The Courier font resident in all Postscript printers is selected The string defined in the above mentioned Printer Config function has no effect when printing to Postscript 6 3 Copy Program This function duplicates an existing program but under a different name retaining the language attribute When this function is selected with you are prompted to enter the n
206. s or minus sign This means that the minimum width of the scientific representation is 8 characters if the field width m is less than 8 then the full width of 12 characters will always be output If m gt 8 then one or more decimal places will be output up to a maximum of 5 decimal places m 12 For m gt 12 leading spaces are inserted before the number Examples WRITE port1 1 23E 10 m S m 7 outputs 1 23000E 10 m 8 outputs 1 2E 10 m 9 outputs 1 23E 10 m 10 outputs 1 230E 10 m 11 outputs 1 2300E 10 m 12 outputs 1 23000E 10 m 13 outputs 1 23000E 10 If the form lt ezm n gt is used then a fixed point representation of the number e will be written with n specifying the number of decimal places to be output No leading spaces will be output unless the field width m is sufficiently large If n is zero then e is output as an integer If e is too large to be output in the specified field width then it is output in scientific format with a field width of m see above Examples WRITE port1 1E2 6 2 outputs 100 00 WRITE port1 1E2 8 2 outputs 100 00 WRITE port1 23 455 6 1 outputs 23 5 WRITE port1 23 455 4 2 outputs 2 34550E 01 WRITE port1 23 455 4 0 outputs 23 4 e is of type character or type string Either lt e gt or lt ezm gt may be used and the character or string of characters will be output in a minimum field width of 1 for characters or the length of the string for string types Leading spaces
207. s than or equal to Ve NMAV gt Ix A Be careful to ensure that all numbers always fall in the range 32767 and 32767 In particular avoid overflow in intermediate results in calculations such as X A B C D E The logical result of comparisons made with the compare operators is 1 if true or 0 if false Expressions An expression is a grouping of numbers variables and functions with arithmetic or comparison operators between them The value of an expression is evaluated from left to right The precedence of operators is ee evaluated first evaluated next gt lt gt lt evaluated last Parentheses can be added as required to alter the order in which an expression is evaluated and signs can also be used at the beginning of any number or expression Statements A statement is a line of BASIC program and consists of a line number between 1 and 32767 followed by one or more commands While it is usual to have only one command per line multiple commands separated by semicolons may be entered A GOTO STOP and RETURN command must be the last command in any line Program A PPC BASIC program consists of one or more statements lines When the direct command RUN is issued the line with the lowest line number is executed first the next higher numbered line is executed next and so on The GOTO GOSUB STOP and RETURN commands can be used to alter this sequence Within a statement execution of commands is from left
208. s to write read is specified by the third parameter These functions are pure binary they do not stop at a null 0x00 For situations where they can be used they are more efficient that making repeat calls to fputc fgetc within a loop The following are the only print f style functions provided int fprintf int port char fmt int vfprintf int port char fmt va_list ap The above differ from the standard C versions only in that the first parameter is an int which specifies the PPC port in the range 1 4 All ANSI features are supported including longs and floats There is no printf although you could define one using a macro in terms of fprintf stdout where stdout is defined in ppclib h as port1 The following are identical to ANSI C and are therefore listed here for completeness only int sprintf char bufname char fmt int vsprintf char bufname char fmt va_list ap All printf type functions return 1 if an invalid port is specified Other returns are as per ANSI C The following are the only scanf style functions provided and are identical to ANSI C int sscanf char bufname char fmt int vsscanf char bufname char fmt va_list ap There is no fscanf i e no conversion of incoming data as it arrives because such a function is practically useless for building a robust system Robust operation involves reading some data into a buffer and then stepping thro
209. should ever be loaded is 2 See the READTIMER function below for a program example READTIMER read a timer FUNCTION READTIMER TIMERNO INTEGER INTEGER The following program code reads characters from Port 3 until 20 characters have been received or until 300ms have elapsed whichever occurs first var timeleft count integer c char loadtimer 7 300 load timer 7 with 300ms chrcount 20 of chars to wait for repeat if ipqcount port3 gt 0 then begin if there is any input data read port3 c then read a char count count 1 and decrement chr count Joadtimer 7 300 and reload the timer end until count 0 or readtimer 7 0 and drop out if done timeout if timeleft 0 then writeln port1 Timeout on Port 3 6 30 PPC PASCAL To check if a timer has expired use an equality test e g timeleft 0 not e g timeleft gt 0 The latter case might not work if the initial timer load value was gt 32767 A channel number which is invalid other than 0 7 will cause a zero timer value to be returned ULED control user LED PROCEDURE ULED ONOFF BOOLEAN This procedure allows the user accessible front panel LED labelled USR to be switched on off according to the state of a Boolean variable This feature can be used to indicate the progress of a program or act as a prompt for some user action or simply for debugging C programs can access all eight LEDs or all 16 on PPCs with two LED displays RE
210. st need the same number of bytes of storage The principal use of this function is to convert one variable into another The example below converts the contents of a character a which should have the value 00h or Oth only into a boolean b var a char Assuming a is a char b boolean and b is boolean b recast a boolean we can convert a gt b with this The previous operation could also have been achieved less efficiently with the Standard PASCAL variant record approach type fiddle record case boolean of define a variant record true x char false y boolean end var f fiddle f x a this converts a gt b b f y The compiler does not check that both parameters use the same number of bytes of storage Use this function with care MEMAVAIL FUNCTION MEMAVAIL INTEGER MEMAVAIL is a parameterless function which returns the number of bytes of free space between the top of the heap and the stack It returns the size of the largest free block of memory It returns an integer and can be used to detect if a program is about to run out of memory and so take corrective action It may be possible to create a dynamic variable that is larger than MEMAVAIL would suggest since there may be Sufficient free space within the heap where space has been freed using DISPOSE For details of how memory is organised at run time see the Program and Data Limits section PPC PASCAL 6 23 PASCAL Dynamic Memory All
211. t 398 bytes into its last two bytes buf fer 399 crcbuf addr buffer 398 0 The INITIAL parameter facilitates the computation of a single CRC over multiple buffers as the following example shows 3434 0934 PPC PASCAL 6 33 var bufferl buffer2 array 1 10 of char cre integer bufferl aaaaabbbbb buf fer2 cccccddddd crc crcbuf addr bufferl 10 0 get CRC of 1st buffer init 0 crc crcbuf addr buffer2 10 crc get CRC of 2nd buffer init last The final crc result above is identical to that produced by var buffer3 array 1 20 of char buf fer3 aaaaabbbbbcccccddddd crc crcbuf addr buffer3 20 0 _BIT integer bit test FUNCTION _BIT VALUE BITNUM INTEGER BOOLEAN This returns the state of a bit in an integer as TRUE or FALSE if the bit is 1 or 0 respectively Only the four least significant bits of BITNUM are used limiting it to 0 15 _AND integer bit wise AND FUNCTION _AND VALUE1 VALUE2 INTEGER INTEGER This performs a bit wise AND of the 16 bits constituting each of the two integers and returns the integer result For example var a integer a _and a 0FFF zero top four bits _OR integer bit wise OR FUNCTION _OR VALUE1 VALUE2 INTEGER INTEGER This performs a bit wise OR of the 16 bits constituting each of the two integers and returns the integer result For example var a integer a _or a 000F set lowest four bits _XOR i
212. t be claimed to withstand 240V AC this would require an isolation specification and test voltage of at least 4500V AC RMS 1 0 Expansion Options 9 3 DG1 Digital 1 0 Card The DG1 option card offers 16 CMOS level schmitt trigger 74HC14 inputs and 16 high current ULN2803A open collector outputs It can be accessed from Pascal and C The external connector is a 44 pin female sub miniature D connector The metal shell of this connector is the same size as that of a standard 25 way D connector Hardware Requirements The minimum requirement is a PPC 4 The present version schematic shown on next page does not support the H2 or H3 options due to the use of the Z80 PIO Installation The DG1 card is normally factory installed in the PPC A field upgrade is possible and involves a PPC ROM change Protection The inputs are protected against overvoltage to 30V by means of series 10k resistors The outputs are not protected Isolation There is no isolation 9 4 1 0 Expansion Options
213. ta The total program space available is 30719 bytes A maximum of 20 programs can be stored Each program reduces the remaining free space only by its exact size plus 19 bytes which are used to store the program name and other information Two markers can appear next to the program directory gt Identifies the program selected for subsequent operations a Identifies the program which will be automatically executed at power up For details see the how to make an autoexec program information later in this chapter Program Name Rules Each program name must be 1 8 characters Any character may be used in the name with the exception of characters which fall within the following three groups 1 A O E A E UA A 2 character codes below 033 decimal 21 hex 3 character codes above 240 decimal FO hex Note that the above does allow most international accented characters such as U0 4 Each program has a language attribute which can be BASIC or PASCAL Additional attributes may be supported in the future The language of a program is determined when the program is created with the Create Program function or alternatively it is generated automatically when the program is transferred over from a PC using KTERM according to the following rules MS DOS filetype PPC language attribute BAS gt BASIC PAS gt PASCAL BIN gt BINARY 3 2 The PPC Executive aj aj PPC Executive functions and facilities
214. ter calibrated PROCEDURE DAC CHAN VALUE INTEGER PROCEDURE DACC CHAN VALUE INTEGER This outputs a signed integer VALUE to the D A channel CHAN Input values in the range 32767 to 32767 produce an output in the range 10V to 10V Valid channel numbers are 1 or 2 The DAC procedure outputs VALUE direct to the converter with no corrections It is slightly faster than DACC but the output can exhibit a scale error up to 45 plus a zero error up to 3 The DACC procedure outputs a calibrated value See ANEERD and ANEEWR for details 6 38 PPC PASCAL aa Execution times The following table shows the approximate execution times of functions listed above Standard PPC H2 option ADC 350us 200us ADCC voltage mode 490us 250us ADCC 4 20mA mode 650s 330us DAC 280us 130us DACC 430us 190us The above timings do not apply to the on board temperature sensor channel 9 for which the figures are approximately 800us and 450us for the standard and H2 PPC respectively ANEERD read analog subsystem calibration EEPROM ANEEWR write analog subsystem calibration EEPROM FUNCTION ANEERD ADDRESS INTEGER INTEGER FUNCTION ANEEWR ADDRESS VALUE INTEGER INTEGER You do not need to know about these functions unless you wish to alter the PPC s analog calibration table This table is factory loaded and if you modify it incorrectly you may have to return the PPC for re calibration
215. ter between 33 decimal 21 hex and 239 decimal EF hex inclusive may be used but you should avoid non displayable characters because of the potential for confusion between what you think you have entered and what you actually entered Before encrypting a program please make a note of the password If you have accidentally encrypted a program and then realised that you have forgotten the password proceed immediately to the Decrypt function and decrypt it Remember the password is case sensitive Password is different from PassWord 6 7 Encrypt program When this function is selected with the currently selected program is encrypted with the currently active password An error message is displayed if no password has been specified An encrypted program cannot be displayed edited printed transferred to a PC or compiled from within the Executive However it can be marked autoexec see 7 and compile execute automatically at every power up Do not use this function unless you have made a note of the password An encrypted program cannot be recovered without the correct password 6 8 Decrypt program When this function is selected with the currently selected program is decrypted with the currently active password An error message is displayed if no password has been specified The PPC Executive 3 5 7 Define power up action Pressing J when this item is highlighted enters a menu PECA Define pawer ap action M1_PHO
216. the comparison will be correct at the cost of a reduction in execution speed The equivalent situation may arise with real arithmetic in which case an overflow error will be issued if the arguments differ by more than approximately 3 4E38 this cannot be avoided lf I is selected then no check for the result of the above comparisons is made Default is I 6 44 PPC PASCAL Option P This option is used to send the compilation listing to a specified PPC port which is assumed to have an ASCII printer connected to it The Postscript output mode is not available The letter P is followed by a single digit in the range 1 4 and this specifies the port For example P2 will send the compilation listing to a printer on port 2 If no P option is specified then the compilation listing is sent to the terminal on port 1 Note that the compilation listing is generated only if the L option has been selected The printer initialisation string which is configurable in the Executive is sent to the printer just before the listing starts Top of File Options The following options must appear before any PROGRAM statement since they all have an effect on the object code produced Normally therefore you would place these options in the first line of your program Option R This controls whether errors generated when reading numbers are fatal R suppresses the Number expected or Exponent expected errors in READ or READLN data input Default is R
217. then write port3 value output value until pos gt i or not suc repeat until all recd data converted If the buffer contains a mixture of integers and reals a single VAL loop cannot be used The easy solution is to read everything as reals VAL can read reals the only change to the above code would be to define value as real An alternative way is to read numbers with the READ procedure with O and R compiler options to prevent any runtime errors However this method does not allow detection of obvious garbage READ will always return a number even if it is meaningless The following example shows how READ can be used to do the equivalent of the example above while not eoln inport do begin read inport value write portl value end Multi byte binary numbers Because all character values can appear with equal probability no character based error checking is possible However if you know that the values must fall within a certain range you can discard any which are outside An additional problem with binary data is that is a byte is lost or misinterpreted all subsequent data becomes garbage Any applications involving the transfer of non character i e integer real etc binary data must prefix a block of data with a sync character which can then be searched for at the receiving end Character translation If just one or two character codes need translating a simple IF is sufficient var c char repeat bread
218. there is no need for e g a preceeding MODE or SETSER command to configure the serial port Therefore you can simply type KTERM and the PPC Executive main menu should appear on your PC If it does not please see the KTERM Troubleshooting text later in this chapter All Executive functions are now accessible to you To exit from KTERM type alt x that means typing x while holding down the ALT key KTERM File Transfer This function allows transfer of user programs between the PPC internal filing system and your PC s hard or floppy disk KTERM 7 1 1 To transfer a file from the PPC to your PC Select the file in the Executive directory with the gt file selector highlight the Transfer PPC gt PC menu item and press ENTER The selected file will be transferred to your PC and will be stored in your current directory 2 To transfer a file from your PC to the PPC Highlight the Transfer PC gt PPC menu item and press ENTER KTERM will now prompt you to enter the name of the file resident on your PC alternatively you can press the TAB key for a menu of candidate files Either way select the desired file and press ENTER The selected file will be transferred to the PPC and will be stored in the PPC s filing system PPC PC filename relationships You will have noticed that files stored in the PPC filing system and displayed in the Executive file directory have no filetypes A filetype is the rightmost 3 character part
219. this error cannot be suppressed other than by reading characters one at a time and processing them intelligently In PASCAL this error can be suppressed with the O and R compiler options however if your input data is likely to contain occassional garbage then you should first read the input as chars into a buffer and process the buffer afterwards Troubleshooting 10 1 A program hangs during communications This can be a handshaking problem caused by the XON XOFF handshake being enabled when it should not be For the explanation see below Loopback tests hang up the PPC You have the XON XOFF handshake enabled If your loopback test uses the full 256 code character set most do then an XOFF character will appear within the data However often this is a standard data input reading problem you need to write any input code to allow for errors with an overall timeout if necessary If your program is written to always expect e g 20 byte packets to arrive and for some reason only 19 bytes arrive in one packet it will hang forever and then probably mis read the next packet RS422 485 Problems Due to a general lack of standardisation in this area one often needs to experiment when connecting to other equipment Check that the A B connections are connected to the corresponding terminals at the other end You may need to experiment by swapping A B Ensure that the 7V to 12V RS422 485 common mode range is not being ex
220. tically placed at the point where the compiler found the error The Compile function s purpose includes The PPC Executive 3 3 IS E aj 1 It ensures that the program compiles without compilation errors This is essential a program which compiles with errors will not generate working machine code 2 It will detect the case where a program s binary output the machine code is too large to run in the PPC This is unlikely to happen except on programs whose PASCAL source program is itself close to filling up the PPC s filespace or when you have declared a too large item of data The total amount of memory in which the machine code runs is approximately 25k and any static data items must fit within this figure also 3 It will report compiler symbol table overflow during compilation As above this is unlikely to occur except on large programs Do not proceed to Compile and Run until your program compiles without any errors O In PPC firmware v1 07 the Compile function can also be used to execute a binary i e compiled C program Previously the only way to run those was to mark them autoexec and reboot the PPC 5 Compile and Run This is similar to the Compile only function described above except that following a successful compilation the binary output is executed When the program s execution ends control returns to the Executive If runtime break checks have been enabled with the C compiler option you can interrupt
221. time error occurred If the program terminates incorrectly e g without END then the message No more text appears and control is returned to the Executive If no errors are detected and the program has been compiled with the Compile and Run function the resulting binary code is immediately executed PPC PASCAL 6 3 PPC PASCAL Syntax and Semantics This section details the syntax and the semantics of PPC PASCAL Unless otherwise stated the implementation is as specified in the Standard Pascal reference Pascal User Manual and Report Second Edition Jensen Wirth Only the first 8 characters of an identifier are treated as significant These first 8 characters should not make up a Reserved Word see the Reserved Words section Identifiers may contain lower or upper case letters Lower case is normally converted to upper case so that the identifiers HELLO HEL1o and hello are all the same Reserved Words and predefined identifiers may be in either case The U compiler option when used causes the compiler to treat upper and lower case letters as distinct so that HELLO HEL1o and hello are all different When you use the U option you must ensure that all reserved words and predefined identifiers are in UPPERCASE See the Compiler Options section for more information IDENTIFIER UNSIGNED NUMBER unsigned integer unsigned integer Integers have an absolute value less than or equal to 32767 MAXINT in PPC PASCAL
222. time into a buffer whether more than one string must be searched for and on the way in which the strings are stored The following complete program supplied with the PPC reads the input data stream and replaces every occurence of string searchstr with string substistr It does this on the fly i e it does not buffer the input data Both strings are stored in char arrays and both must be terminated by a null 0 This means that neither string may contain the character 0 The program works by comparing each input char with the first char of the search string if there is a match then it compares subsequent chars If there is a mismatch before the end of the search string has been reached then the input chars matched so far are passed on without change recursion is used at this point to ensure that if the search string matches partly and the first non matching character is the start of a new search string the program identifies the new search string correctly The program allows the substitute string to be of zero length i e its 0 terminator character being in position substistr 1 This mode will remove the search string and replace it with nothing The search string must be at least one character long plus the 0 terminator Doubtless you will see more elegant versions of this program in Pascal books but this one works and should be fairly easy to understand program stringxl var ch char inport outport text searchst
223. tion then the Port 1 baud rate during the KTERM session only will be 38400 baud If your program is designed to do something with Port 1 at 9600 baud and configures Port 1 accordingly your debug statements would not be receivable with KTERM 8 8 PPC Serial Ports aj aj Cables With the exception of the CDO signal which is not provided on a PC all the PPC signals have the same input output direction as the corresponding pins on the 9 way serial port of an IBM compatible PC AT Therefore when driving most output type devices printers plotters etc the cable which previously worked between a PC and the device can often be successfully used between a PPC and the same device The cable information in this section is for guidance only Always refer to the manuals for the equipment being interconnected before proceeding A standard serial cable does not exist Ensure that your cables contain only those connections required for the job Some devices have special voltages on certain pins and these can damage the PPC Avoid using standard cables containing all the 25 possible connections Connect cables only when the equipment being interconnected is switched OFF Modems Please refer to the Modem Control section in this chapter for details PPC Loopback Adaptors The Serial Port Tests function in the Executive requires special loopback adaptors to be connected to ports 2 3 4 The connections for each ad
224. tiple items may be read in a single INPUT command INPUT X Y Z and BASIC will prompt for each one separately You can modify the standard INPUT prompt by including a string INPUT Enter value of X X and the prompt X is replaced with Enter value of X Both single and double quotes may be used provided they are matched The INPUT command is designed for interactive operation and is not suitable for reading e g numbers from a continuous input data stream DAC This command outputs a value to the specified channel of the PPC 16 bit digital analog converter DAC The DAC is available only if the ANALOG SUBSYSTEM option has been fitted otherwise its execution will generate a fatal error DAC C X outputs value X on channel C of the DAC The channel number is 1 2 in present 2 channel DAC versions but could vary in the future The output value can range from 32767 to 32767 corresponding to a nominal analogue output range of 10V to 10V The command DAC 1 16384 generates a 5V output on channel AOUT1 the first DAC channel SEED This specifies a seed for the pseudo random number generator Any value between 1 and 32767 may be used Example SEED 155 This command can be used to initialise the random number generator to ensure that repeated runs of a program that invokes the RND function produce the same results STOP This command stops the execution of a program It may appear many times in various parts of a program
225. to point somewhere else before referencing V The memory freed may then be subsequently used when creating other variables using NEW DISPOSE must be use with care since for example after NEW v1 v2 v1 DISPOSE v1 v2 will no longer point to valid data MARK PROCEDURE MARK VAR V This procedure saves the state of the dynamic variable heap to be saved in the pointer variable V The state of the heap may be restored to that when the procedure MARK was executed by using the procedure RELEASE see below The type of variable to which V points is irrelevant since V should only be used with MARK and RELEASE never NEW RELEASE PROCEDURE RELEASE VAR V This procedure frees space on the heap for use of dynamic variables The state of the heap is restored to its state when MARK V was executed thus effectively destroying all dynamic variables created since the execution of the MARK procedure and as such t should be used with great care If the procedure DISPOSE has been used it is possible that not all such variables will be destroyed To delete individual variables use DISPOSE 6 24 PPC PASCAL Examples The following example program allocates a 1000 byte array on the heap reads 1000 bytes into it operates on it in this example it just converts any lowercase characters to uppercase outputs it and eventually de allocates it type buffer array 1 1000 of char pbuf fer buf fer var b pbuffer i integer
226. to right The IF command can be used to skip over the execution of all commands to the right of the IF 5 2 BASIC In the PPC Interactive Basic mode a program resides in memory This applies whether it has been typed in or loaded with the LOAD command A power loss or a PPC reset will cause that program to be lost The SAVE command can be used to store the program in the PPC s filing system The execution of a program can be terminated with the STOP command by reaching the end of the program or with a ctrl c break key However ctrl c works only on programs running in the Interactive Basic mode it will not break out of a BASIC program running in autoexec mode In other words break checking cannot be disabled except by running the program in the autoexec mode If a BASIC program terminates due to a runtime error e g an integer overflow or division by zero then all variables are re initialised and the program is restarted from the first line There is no facility for ignoring runtime errors BASIC 5 3 BASIC Functions Functions are program elements which return a value PPC BASIC currently contains the following functions ABS This return the absolute value of an expression X ABS 6 returns X 6 RND This is a pseudo random number function X RND 100 returns a pseudo random number between 1 and 100 inclusive in X The command SEED can be used to set the seed for the pseudo random number generator to a particu
227. ued any command the execution of which would overwrite the block in the block buffer If you respond Y then the block in the block buffer will be lost and the command executed while any other response will abort the command Abandon file Sure This prompt requires a single character response It is produced after the Exit and Abandon command Respond Y and the current text will be lost and you will be returned to the Executive Any other response will abort the command Go to line This prompt requires a string of numbers terminated by 1 It is produced after the GO TO LINE command The response is interpreted as a line number and the maximum allowed length is 4 characters only numbers are accepted J alone aborts the command Editor Error Messages There are twelve messages produced by the editor and they appear mainly on the upper status line Out of memory Indicates that there is not enough space in the machine to carry out the proposed command Line is too long Produced when the length of the line would exceed the maximum allowed length 255 characters if the proposed action was taken This might either be simply the press of a key or the deletion of a lt CR gt Undefined command Indicates that the initial key of a command is correct but the second or subsequent keys do not form a valid command Block start unmarked Block end unmarked Produced after any block operation if the start end of the block has not been marked
228. ugh the buffer and intelligently identifying its content In any case typical scanf implementations read chars into a buffer whose existence is hidden somewhere in the runtime library and whose size is fixed at e g 256 bytes and upon receipt of a LF Ox0A WM process the buffer Such mode of operation would be useless for data which does not have an LF or which overflows the buffer Avoid using the name port for anything This is a reserved word in Hi Tech C It is a typedef for a pointer to CPU 1 0 addresses The Hi Tech manual contains full details When programming the PPC you never need to access 1 0 ports directly unless you are doing special hardware specific software or are accessing a custom 1 0 card 1 0 Queue Management Functions In a device like the PPC data flow generally never ends although it may of course have gaps in it and one common PC disk file oriented programming style where a program terminates when e g an EOF is returned when reading a file is not suitable for the PPC Instead your program will typically contain a loop where it tests for data in the input queue tests space in the output queue if both are OK it reads the input data processes it and outputs it then returns to wait for more input The following functions support this programming style and also allow the creation of programs which process communications on multiple ports concurrently int ipqcount int port returns of bytes i
229. ur PC s display monochrome or colour on a monochrome or colour PC respectively KTERM obtains display size information from the BIOS and this is not 100 reliable one can confuse KTERM by using a monochrome monitor with a VGA card configured for a co our monitor MI Forces an inverse monochrome display Above comments for m option apply NB Forces KTERM to access your display via the PC s video BIOS This mode is automatically selected with monochrome and CGA displays The main use of this option is to prevent snowing on the display or to achieve correct operation with not quite IBM compatible display hardware NF Forces KTERM to access your display directly via the hardware This mode is automatically selected with EGA MCGA and VGA displays This option can produce faster display updating when running on a slow PC especially at 38400 baud but can cause snowing on some displays The snowing can be suppressed with the vb option MNI You should never need to use this option It disables the mechanism which KTERM uses to advise the PPC of the new baud rate The only time this option is useful is if you inadvertently configured the PPC to power up with an Executive Mode baud rate other than 9600 baud Rates of 1200 38400 can be configured in the PPC for special scenarios such as modems or fast dumb terminals If this happens you must use SETSER or an equivalent program to configure the PC baud rate to the baud rate
230. us of a PPC front panel switch The value is O or 1 for switch not pressed or pressed respectively Switch number is 1 2 3 Example X SWI 3 returns X 0 if switch SW3 is not pressed otherwise X 1 5 4 BASIC BASIC Commands PPC BASIC commands are listed below with examples Multiple commands separated by semicolons may be placed on the same line A command may also be executed in a direct mode by entering it without a line number For example entering the direct command PRINT 25 6 no line number will output the result of 150 However to build up a multi line program each line must start with a line number Program lines may be entered in any order PPC BASIC will automatically insert each line into the correct sequence in the program according to ts line number Each command name below in bold is followed by its description and one or more examples REM This allows remarks comments to be inserted into a program REM This line is a comment and is ignored by BASIC LET This optional keyword preceeds an assignment of a value to a variable LET X 25 6 5 these two examples are equivalent X 25 6 5 PRINT This is a multi purpose command for outputting the values of BASIC variables expressions and text strings It can be used in many different ways as the following examples show PRINT outputs just a blank line a CRLF a carriage return and a line feed PRINT TOTAL X outputs TOTAL followed by the decimal value
231. vert all lowercase characters to uppercase and output the resulting data on PPC port 4 program convert var c char begin repeat bread port3 c c toupper c bwrite port4 c until false end Note one important feature which most PPC programs will have in common it runs forever and unlike a program written e g for a personal computer it never terminates The until false statement produces a loop with no exit More examples are given in the Programming Examples section and on the supplied diskette How am going to learn PASCAL While there are sufficient examples in this Manual to illustrate the major elements of the language and to get you started it is beyond the scope of this Manual to teach you all of PASCAL If you are completely new to PASCAL please refer to the Recommended Books section However please remember that you are using the PPC to do a job You are not trying to pass an examination in computer programming Therefore keep your program simple and stay away from the more exotic Pascal language constructs unless you are into that type of thing Nearly all datacomms related PPC programs can be easily written without using records pointers and all the other weird language features which can be found in the Pascal books How to create edit and compile a PASCAL program Use the Create File function in the PPC EXECUTIVE and then use the PPC text editor to enter the program Alternatively a program can be typed
232. wer up to eight 4 20mA jumper selectable on a channel by channel 16 bits are significant and can be further nominal power supply for powering standard 4 20mA self powered transducers Each of the eight possible transducers connects between this supply and its analog input terminal each of which has a jumper selectable 47R resistor to gro on the 1V range After removing the 4mA zero offset the resulting un und The voltage across the 47R is measured ipolar reading is valid to just under 15 bits lf a floating regulated 10V supply is required e g for bridge transducer excitation the AP option provides a suitable floating output However if the 10V output is utilised the 24V outpu t is not generally usable because its ground 9 2 1 0 Expansion Options reference is now floating For similar reasons the floating 10V output can be used to power only one bridge transducer at any one time For control applications two DAC outputs D2 option are available These share a common ground with the ADC circuitry Two TTL level outputs and two TTL level inputs are provided These share a common ground with the ADC DAC circuitry Hardware Requirements To support the Analog Subsystem the minimum requirement is a PPC 4 Accuracy and Performance The Analog Subsystem utilises calibration coefficients corrections which are generated during factory test and stored in an on board EEPROM non volatile memory Sepa
233. which can be 30 50 smaller Pass structures arrays and other large objects by reference rather than by value Dont use fprintf or sscanf unless you really need the flexibility which these very comprehensive functions offer For example when reading integers from input data using atoi or atol can be much faster than using sscanf However doing so will not reduce program size because all these functions are already provided in the ROM based C runtime library In 1 0 involving blocks of data use freadc and fwritec in preference to calling fgetc or fputc many times in a loop Avoid using the heap functions i e malloc free etc unless you always free memory blocks in precisely the reverse order in which they were allocated to eliminate fragmentation Unlike a PC the PPC is unable to advise the user that the program has run out of memory Technical Support Questions on how to use the PPC any of the PPC specific C extensions and any suggestions are all welcome C Reference 12 7 Other Products Inline RS232 RS4xx Converters and Isolators A range of high quality very low cost RS232 to RS422 485 converters is available All units plug directly into an IBM PC serial port 25 way or 9 way and are line powered from the RS232 interface s RTS or DTR signals Isolated models 1kV RMS test are also available Please see www kksystems com for full details and pricing of the whole range The KD485 is a multi purpos
234. wn below Program Manager ld File Options Window Help DOS Applications Windows Applications Accessories E m amp A A gt Qi gt O ES pa KTERM PZPCap CorelDRAW MOSAIC Corel TRACE WFNBOSS Write Paintbrush Terminal Notepad O i SS gt 85 E Excel Recorder Cardfile Calendar Calculator Clock PIF Editor Duk 1 Settings kterm vi ey 7 gt Games fh Me OR O v DO eve 8 49 pH OMICRON ord 8 b 7 ie Reversi CALCSOL Note that KTERM will initially be invoked in the basic mode with no command line options at 9600 baud You may wish to edit the command line in the KTERM PIF file or in the Program Manager Properties menu see your Windows Manual to select e g a 50 line VGA mode VL option and a higher baud rate The above screen shows KTERM running with the VL option under Windows 3 0 with a super VGA 1024x768 display in 386 enhanced mode Note also that any serial port baud rate settings set up in the Windows Control Panel are irrelevant because KTERM accesses the serial port hardware directly configures the port as required and upon exit with alt x restores the original configuration Using the standard Windows 3 x cut and paste functions it is possible to cut and paste text from KTERM run
235. wo ways you can maintain an unlimited number of PPC programs on the PC either on a floppy or on a hard disk and download these files to the PPC as required You can also use your favourite non document editor to create and edit PPC programs O KTERM supports the 43 and 50 line EGA VGA display modes in the PPC editor These modes are preferred for editing because they make visible a larger part of the program being edited Note that although some commercial programs e g PROCOMM PLUS do support extended video modes these modes are not easily usable with the PPC because KTERM uses special ESCape sequences to tell the PPC the terminal screen dimensions KTERM installation No installation is required Just copy KTERM EXE from the diskette to a convenient directory on your hard disk make sure it is in the PATH or on a floppy only PC copy it to your working diskette KTERM operation By default KTERM uses your PC s COM1 serial port at 9600 baud no parity 8 bits word and 1 stop bit Therefore connect the PC PPC cable see Serial Ports and Cables chapter as shown in the following diagram Use a 9 25 way converter here i necessary Ensure that the PPC is powered up and the EXE indicator is flashing If EXE is not flashing then the PPC has probably been programmed to run a program at power up please see the PPC Executive chapter on how to enter the PPC Executive mode KTERM sets its own serial port parameters and
236. x Windows 95 WindowsNT4 0 0 00000000000 7 5 Running KTERM over a modem link aaa aaa 7 6 Cables Tat 3 ek ope ARAN TO 7 6 PEG COMTOUFAU ON ss sade a ei a pl Ta a a dd ir 7 6 Modemicontig ratiON eto ida a BANS a a ide tea J 7 6 KTERM USAGES ons soc Ai AAA na 1 7 A A curacy foots ian a Aig Wye lage an te butets anaa bs Getag le tee Maka 7 7 TERM Troubleshooting anri cars are er leew ah Seda at Bea DM dep ut Pw end a 7 9 Executive menu does not appear at all ooo 7 9 Garbl d data PS fcr gs ar Sate Monel ie Marae satiated Rea aha ete Ait osea 7 9 Editor display is incorrect or other display faults a oo oo o 7 9 Control c does not stop program execution ti gos ae Ge ee each oe pts a it eR 7 9 KTERM Error Messages 2 arar ia e bas 4 7 9 PRC Serial POMS amp AO uci aa ais EE i ai 8 1 Hardware Interface A O a ani Gold wy week Reke a 8 1 PIM FUMCUONS 2 at a ado iS CIO ADOTE TE na 8 1 Hardware Interface RS422 RS485 oooo o ooo conos 8 2 RS422 RS48 3 0TOUNAIAO sa tl ds Ad 42 8 2 RS422 RS405 Termination bo Ts a Ar Ge doce A Ads ta 8 3 RS232 to RS422 RS485 port conversion acacia A e oN 8 3 PPC E DINAIG IZ connections oe anu e e dr ita I 8 4 ASARS IR VEL COMM le rat soda ado dida dde esate dd Di cda rd Gentes Mia Me Ah ge 8 4 POUM da ara dat dis tirado 8 5 Transmit QUEUES deso e a Aa da de aaa Aare 8 5 Receive QUBUES ae entice ice ch ik ate E anne e sd eae WE ey 8 5 AMOS AKG a8 a ck et preg Tae e
237. ystem PASCAL functions These functions are available only on a PPC fitted with the optional 16 bit Analog Subsystem option For full details of this option see the Analog Subsystem Option chapter ADCINI initialise ADC FUNCTION ADCINI INTEGER This function should be called at the start of any program which accesses the PPC Analog Subsystem It invokes the ADC self calibration cycle which takes about 1 8 seconds A non zero return indicates that the Analog Subsystem option is not installed or is faulty This function also sets the output of the two D A converters to zero It is also the recommended way of checking if the Analog Subsystem is fitted ADC read analog digital converter ADCC read analog digital converter calibrated FUNCTION ADC CHAN INTEGER INTEGER FUNCTION ADCC CHAN INTEGER INTEGER This function initiates an A D conversion on the channel specified by CHAN and returns a signed integer which represents the analog input voltage reading The channel number CHAN s 1 18 used as follows 1 8 channels AIN1 AIN8 use with inputs configured for voltage mode 100mV 1V either ADC or ADCC function may be used 9 on board temperature sensor use ADC function only not ADCC 10 invalid 11 18 channels AIN1 AIN8 use with inputs configured for current loop mode 4 20mA use ADCC function only not ADC On the standard product version a 100mV 1V nominal input range produces a digital reading in the

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