Model 995 Dual Counter Operating and Service Manual
Contents
1. rn 21 A 5 TIME UNITS USED IN COMMANDS I I ene 21 6 CATALOG OF COMMANDS FOR THE 995 21 APPENDIX B RESPONSE RECORDS FROM THE 995 MODULE 23 B 1 DELIMITING CHARACTERS 23 B 2 PERCENT RESPONSE RECORDS sr ccas prebiu 23 DOLLAR RESPONSE RECORDS 24 APPENDIX C OPTIONAL PARTS LIST 25 C 1 CABLES AND CONNECTORS 0000s 25 C 2 ORDERING INFORMATION e I n 25 vi SAFETY INSTRUCTIONS AND SYMBOLS This manual contains up to three levels of safety instructions that must be observed in order to avoid personal injury and or damage to equipment or other property These are DANGER Indicates a hazard that could result in death or serious bodily harm if the safety instruction is not observed WARNING Indicates a hazard that could result in bodily harm if the safety instruction is not observed CAUTION Indicates a hazard that could result in property damage if the safety instruction is not observed Please read all safety instructions carefully and make sure you understand them fully before attempting to use this product In ad2. 2 9 GONTROES bg mIRC IU uU E Rud be axi eripe and 2 ZA INPUTS EI 2 2 5 Obl PETS Aik teh seus aca 3 2 6 INTEREAGES na Bie OE ee ene Qv NEM CDI etn oo She OE 3 2 7 ELECTRICAL AND MECHANICAL 3 INSTABEATION eet ance ee Mee Banas eee 4 3 1 INPUT POLARITY SELECTION cect teens 4 32r GENERAL canta eb RES EE coe RIO CR ar es nee Ro etal ates 4 3 3 CONNECTION TO POWER 4 3 4 SIGNAL CONNECTIONS 2 2 22 herr 4 3 5 OUTPUT GONNEGTIONS rne Ra Tu SERE Ge ek eee Pe wees UIS 5 3 6 OPERATION Lini vets eee Bh eka gp e reete Gatley help ee dee euis 5 4 OPTIONS FOR THE MODEL 995 5 4 1 RS 232 C INTERFACE MODEL 99X 1 0 0 0 cc tte eee 5 4 1 1 20 mA Current Loop 7 4 1 2 Using the 99X 1 with a 7 4 1 3 Installation 5 8 4 2 IEEE 488 GPIB INTERFACE MODEL 99X 2 8
3. Fig 4 is located on the PWB to select one of the three operating modes Master Slave or Normal This switch determines the role of the individual modules when contained in a counting system As a Master the 995 drives the system gate lines but does not respond to a system gate driven by another device As a Slave the 995 does not drive the system gate or the system reset signals but does respond to both In the Normal position the 995 does not drive or assy 714850 3 SCHM 729129 t 1 EEDS 21 Rv 0 0 NORMAL OM ION Fig 4 Selecting Operating Modes on the 99X 3 Print Loop Interface Board respond to the system gate or system reset signals When used with a Model 879 controller module the usual operating mode would be the Slave mode Two jumpers W1 and W2 are located on the printed wiring board Both have two positions labeled DUAL and SINGLE which represent the number of counting sections associated with the Counter module in which the interface is used For the 995 both jumpers are to be in the DUAL positions The Print Loop Connection is made through a 14 pin connector accessible through the rear panel of the 995 A standard print loop cable ORTEC Model 772 C1 is used to connect the 995 to the other modules in the data acquisition system The connections in the cable are listed in Table 6 The print loop signals are included in the 14 pin connector on the Print Loop
4. INPUT POLARITY JUMPERS Two jumpers located on the printed wiring board PWB separately select the desired input polarities for inputs in A and in B P positive N negative 2 4 INPUTS INA e Positive Input Front panel BNC connector for Counter A accepts positive unipolar signals minimum width above threshold 20 ns at a 5096 duty cycle The threshold is adjustable from 100 mV to 49 5 V via a front panel 25 turn trimpot Zin 1000 to ground dc coupled e Negative Input Changing the Input Polarity Jumper position on the counter board permits selection of the fast negative logic input which is designed to accept 600 to 1800 mV pulses with a fixed discriminator threshold of 250 mV 2 50 dc coupled Minimum pulse width above threshold is 4 ns IN B Identical to In A except that it feeds Counter B ENABLE Front panel BNC input connector accepts NIM standard slow positive logic pulses to control the counting condition of the entire module A level of gt 3 V or open circuit allows counting provided the instrument is in the Count mode and has not reached the preset value lt 1 5 V inhibits counting The driving source must be capable of sinking 5 mA of positive current during inhibit protected to 25 V GATE BNC input is identical to the Gate B input GATE B Rear panel BNC connector accepts NIM standard slow positive logic signals to control the counting in Counter B A leve
5. STOP command is sent to the 995 STOP 000000069 gt SHOW_COUNTS 00000000 00000000 000000069 gt This command shows the version of firmware installed in the 995 This command selects Counter B value to be displayed This command selects Counter A and the display should read 0 This command shows the contents of Counters A and B separated by a semicolon 14 10 REM SAMPLE PROGRAM FOR THE IBM PC AND COMPATIBLES 20 REM OPEN SERIAL PORT FOR COMMUNICATIONS 30 REM SET PORT FOR 9600 BAUD NO PARITY AND 8 DATA BITS 40 OPEN COM1 9600 N 8 AS 1 50 REM DEFINE SUCCESS RESPONSE FROM THE 995 60 96000000069 70 REM INITIALIZE THE 995 TO A POWER UP CONDITION 80 PRINT 1 INIT 90 REM READ RESPONSE RECORD FROM THE 995 AND STOP IF NOT OK 100 INPUT 81 RESP 110 IF RESP lt gt OK THEN PRINT RESP STOP 120 REM EXERCISE A FEW OF THE COMMANDS 130 PRINT 1 CLEAR_COUNT 140 INPUT 1 RESP 150 IF RESP lt gt 1 OK THEN PRINT RESP STOP 160 REM READ COUNTER VALUE 170 PRINT 1 SHOW COUNTS 180 INPUT 1 CNT 190 INPUT 1 RESP 200 IF RESP lt gt 1 OK THEN PRINT RESP STOP 210 REM LOAD DISPLAY SELECT AND READ IT BACK 220 PRINT 1 SET DISPLAY 1 230 INPUT 1 RESP REM READ RESPONSE RECORD 240 PRINT 1 SHOW DISP 250 INPUT 1 ANS REM READ VALUE BACK 260 INPUT 1 RESP REM READ RESPONSE RECORD 270 D MIDS ANS 3 3 280 IF VAL D lt gt THEN PRINT ANS STO
6. has the capability through the print loop to start and stop counting reset and read the contents of l STANDARD NIM DIGITAL BUS NIM GPIB DOE ER 01 73 U S NIM committee August 1983 IEEE Standard Digital Interface for Programmable Instrumentation ANSI IEEE Std 488 1978 The Institute of Electrical and Electronics Engineers 345 East 47 Street New York NY 10017 and Codes and Format Conventions for Use with ANSI IEEE Std 488 1978 ANSI IEEE Std 728 1982 The Institute of Electrical and Electronics Engineers 345 East 47 Street New York NY 10017 Counters A and B in the Model 995 along with the other counters in the print loop The inputs to Counters A and B are individually selectable as either positive or negative sensing inputs by changing the input Polarity Jumpers on the counter printed wiring board PWB The negative input mode is designed to accept standard NIM fast negative logic pulses with a fixed threshold of 250 mV on a 50 0 input impedance The negative inputs can handle counting rates up to 100 MHZ The positive input mode can accept counting rates up to 25MHz on a 1000 input impedance To enhance the flexibility of the positive input mode precision discriminators are included on both counters The discriminator thresholds are variable over the range of 100 mV to 49 5 V using front panel 25 turn trimpots The thresholds can be adjusted to suit the amplitude of a specific source of logic pulses or used a
7. l x DL one 8 0 unsigned binary integer The integer is transmitted as three ASCII character digits xxx which are the decimal equivalent of the binary integer The decimal value will be between 0 and 255 The final three characters CCC are three ASCII character digits representing the checksum value for the record as a three digit decimal value DL is an appropriate delimiting character See SHOW DISPLAY and SHOW MODE commands in Appendix A The F response record is used to transmit a variable length string of printable ASCII characters shown here as It may consist of one or more characters No checksum is used and DL is an appropriate delimiter The command generating a F record is SHOW_VERSION A l response record is used to transmit a single character record either an ASCII for true or an ASCII F for false represented in the example by x DL is an appropriate delimiting character The command generating this record is SHOW ALARM 25 APPENDIX C OPTIONAL PARTS LIST C 1 CABLES AND CONNECTORS A maximum cable length of 50 ft 15 m should be used for the RS 232 C interface The following cables should only be used for data rates of 9600 baud or less higher rates require shielded cables to minimize RF interference with other devices located in the area Module Description C 2 ORDERING INFORMATION For ordering information contact your ORTEC sal
8. whose total transmission length does not exceed 20 meters Data rates through any of the 16 signal lines that comprise the bus must be 1M byte s and consist of digital data only The bus is connected in parallel to all components of the system and is designed to ensure reliable data transfer throughout the network Eight lines of DIO1 DIOS8 are used for the transfer of data between the components of the system Three lines DAV NRFD and NDAC are used as transfer control The remaining five lines IFC ATN SRQ REN EOI are for bus management These lines may employ either open collector or tri state drivers as defined by the IEEE 488 1978 standard Information is transmitted over the eight data lines under direct supervision ofthe three transfer control lines Transfer proceeds as fast as the components of the system can respond but no faster than the slowest device currently addressed by the bus This permits multiple data transfers to more than one device on the bus at a time Active devices connected into the system may be talkers listeners controllers or a combination of the three but no more than one device may be designated as a talker at any given time The controller determines the role of each of the devices by sending out an address of the device to be defined Addresses of the devices are set at the time of system configuration before power is applied by means of an 8 position DIP switch Sections 1
9. 69 DEV4 The numbers represented by the Xs in the first record should match the numbers showing in the display of the 995 Remember that two response records must be read for every SHOW command Using the above examples refer to Appendix A and exercise the remaining commands to become familiar with the commands and the response records The following is asample program written in BASIC to show how some of the commands may be used in a program The same format holds for any programming language used The following program must be preceded by steps 1 through 99 of the program DECL BAS see Installation Instructions in the IBM Interface Manual 100 REM THIS PROGRAM MUST BE APPENDED TO DECL BAS PROVIDED 101 REM BY THE INTERFACE MANUFACTURER 102 REM 103 REM MAKE SOME ASSIGNMENTS 104 LF CHR amp HOA REM LINEFEED CHARACTER 105 COUNTERS DEV4 REM REFER TO DEV3 AS COUNTER IN PROGRAM 106 GPIBO GPIBO REM GPIBO REMAINS GPIBO 107 CALL IBFIND GPIBO GPIBO 108 CALL IBFIND COUNTER COUNTER 109 9000000069 REM RESPONSE GENERATED IF EVERYTHING 110 REM THIS PROGRAM TESTS THE COMMUNICATIONS BETWEEN THE 995 111 REM AND THE COMPUTER 112 REM 120 REM FIRST TEST THE SERVICE REQUEST TO SEE IF STARTING FROM 121 REM A POWER UP 122 REM 130 CALL IBRSP COUNTER SPR REM SERIAL POLL TO 995 131 S SPR AND amp H40 REM TEST SERVICE REQUEST 132 IF S 0 THEN 140 ELSE PRINT STARTING
10. Examples Before connecting the 995 to the IBM interface there are some important considerations regarding the setup of the software drivers which must be done before attempting to communicate with the 995 These are described in the installation and users guide which comes with the interface These involve the creation or editing of a file called CONFIG SYS to let the DOS know that the interface is installed Also there are modifications which may have to be made to a file called GPIB COM This is done by running a program called IBCONF This allows the selection of the device number and address of the 995 on the bus These programs are described in details in the users guide for the IBM interface When these initial setup procedures have been completed connect the 995 to the computer and apply power to the 995 As with the H P computer it is much easier to become familiar with the command format and response records by using the computer in an immediate mode To do this with the IBM a program called IBIC must be run Type IBIC to start the program and follow instructions when the logo appears The following is a step by step example of communicating with the 995 The text appearing in upper case letters is generated by the computer commands typed by the operator are in lower case letters PRESS F1 FOR HELP GPIBO set dev4 DEV4 Commands to the 955 only sent when the prompt DEV4 is present Because the 995 has just
11. TRANSMIT Bee wa w 3 m w2 RECEIVE manu wt au lt 4 AO T K9 MODEL 99x 1 P N 6905508 aD 85 232 INTERFACE SCHM 726968 e 8551 728710 vi PITT IT IVT is connected The switch setting are given in Table 3 In addition to the baud rate selection the format of the data bits ASCII characters must also be set to match the device to which the 995 is connected To accomplish this an 8 position DIP switch Fig 2 is provided to allow the operator to select the number of data bits parity enable or disable odd or even parity if enabled and either one or two stop bits These must match the device to which the 995 is connected Table 4 defines these selections Table 1 RS 232 C Connections Pin Pin No Signal No Signal 1 protective ground 14 2 transmit data 15 3 receive data 16 4 request to send 17 POSITIVE TRANSMIT 5 clear to send 18 6 data set ready 19 7 signal ground 20 dataterminal ready 8 21 9 22 10 23 POSITIVE RECEIVE 11 24 NEGATIVE TRANSMIT 12 25 NEGATIVE RECEIVE 13 S2 8 DATA BITS 7 DATA BITS e ENABLE PARITY H DISABLE PARITY PARITY EVEN 3 PARITY 2 STOP BITS 4 1 STOP e N A 5 N A i RECYCLE 6 ONECYCLE 7 COUNTER ONLY 8 88 232 Fig 2 Changing Jumpers on the 99 1 RS 232 C Interface Board Asterisks
12. byte contains information about the status of the 995 and is defined in Fig 5 Bit7 Bit6 Bit 5 Bit 4 Bit 2 Bit 1 Bit 0 L Ovflo A Ovflo B Undefined ___ undefined Fig 5 Serial Poll Status Byte Undefined Ready Undefined Requesting Service The 995 will not accept another command until the response recordis read The ready condition will be indicated by a serial poll status byte with only bit 4 asserted Install the Model 995 in the bin and connect the IEEE 488 bus cable to the connector on the rear panel of the 995 Turn on the power to the bin The easiest way to become familiar with programming the 995 via the IEEE 488 bus is to use the immediate mode of communications whereas the computer can be used as a terminal to exercise the commands This method can be used to become familiar with the protocol of the GPIB and the 995 communications structure The following examples for the Hewlett Packard and the 1 compatibles will show the command formats and responses from the 995 5 2 1 Hewlett packard Computer Examples The first computer system discussed will be the Hewlett Packard which should apply to the HP 85 15 family and the 9816 9826 and the 9836 computers The computer should be set to terminate each data transfer with a line feed character Refer to the operating manual for set up procedures Since the Model 995 has just been powered up there wil
13. interface board and in each of the other units in the printing loop system All of the signals except one are in parallel to all units in the system The exception is Previous Module Finished as an input to the module and This Module Finished as an output to the next module This signal ripples through the printing loop to indicate to each module when its turn to transfer data has occurred The order in which modules transfer data is determined by the cables and their relative positions in the loop Table 6 Print Loop Signals Pin No Signal Name 1 Data 1 Data 2 3 Data 4 4 Data 8 5 Print 6 Print Advance 7 Previous Module Finished 8 System Gate 9 System Preset 10 System Reset 11 Ground 12 Control 13 This Module Finished 14 This Module Printing DATA LINES 1 2 4 8 transfer the four bits of BCD data from the assigned module to the Controller module Each module drives these lines only during its turn for printing PRINT prepares the modules in the loop for data transfer PRINT ADVANCE advances the module through its digits during data transfer It starts with the most significant digit and scans sequentially to the lowest significant digit PREVIOUS MODULE FINISHED starts the actual data transfer from an instrument when its turn has occurred SYSTEM GATE carries a signal to all modules set for Slave operation in the system loop This signal can be used to synchronize the data collection time for all modules in t
14. 4 2 1 Using the 99X 2 with a 9 4 2 2 Installation 5 10 4 3 PRINT LOOP INTERFACE MODEL 99X 3 10 4 3 1 Installation 5 12 4 4 INTERNAL 6V SUPPLY OPTION MODEL 99 4 12 4 4 1 Installation 5 12 5 PROGRAMMING THE 995 4263 a pus orden wh bobus Sed bte eyes CIEN HE 13 5 21 RS 292 GC INTEREAGE Pei eee MEAT Ve Db eDCPEL Nu E PPS vp MET ME MS 13 5 1 1 Terminal Operation 13 5 1 2 BASIC Programming 14 5 2 INTERFACING TO THE IEEE 488 BUS nen 14 5 2 1 Hewlett packard Computer Examples 15 5 2 2 IBM PC Programming Examples 17 APPENDIX A ASCII COMMANDS TO THE MODULE ssssssse e 20 AT COMMAND WORDS x We up x X mE Seg a ee Iq 20 1 2 DATA VALUES es ode undas qos sendet recu tte ode ud 20 Ags 2 GHEGCKSUMS edes map tee toner e ett Beside uet bs E dard 21 A 4 RESPONSE FROM THE
15. FROM POWER UP 133 CALL IBRD COUNTER RD REM READ POWER UP RESPONSE 134 REM 135 REM SKIP INIT COMMAND IF STARTING FROM POWER UP 136 GOTO 150 20 137 REM 140 REM SEND INIT COMMAND TO 995 141 WRT INIT LF REM ALL COMMANDS MUST TERMINATE WITH LF 142 CALL IBWRT COUNTER WRT REM SEND COMMAND 143 REM WAIT FOR COMMAND TO BE EXECUTED 144 FOR I 1 TO 100 NEXT 145 REM READ RESPONSE RECORD FROM INIT COMMAND 146 CALL IBRD COUNTER RD 147 REM 150 REM TEST START AND STOP COMMANDS 151 WRT START LF 152 CALL IBWRT COUNTER WRT REM SEND START COMMAND 153 CALL IBRD COUNTER RD REM READ RESPONSE RECORD 154 REM ALLOW TIME FOR SOME COUNTS TO ACCUMULATE 155 FOR 1 TO 200 NEXT I REM DELAY LOOP 156 REM NOW STOP COUNTER AND READ COUNTS 157 WRT STOP LF 158 CALL IBWRT COUNTER WRTS REM SEND STOP COMMAND 160 REM READ RESPONSE RECORD 161 CALL IBRD COUNTER RD 170 REM 171 REM READ COUNTS FROM 995 COUNTER 172 WRT SHOW_COUNTS LF 173 CALL IBWRT COUNTER WRT REM SEND COMMAND 174 REM READ CONTENTS OF THE COUNTER AND DISPLAY THE VALUE 175 CALL IBRD COUNTER RD REM READ VALUE 176 PRINT RD REM DISPLAY VALUE 177 REM READ SECOND RESPONSE FROM SHOW COMMAND 178 CALL IBRD COUNTER RD 179 REM 180 REM THIS CONCLUDES THE COMMUNICATIONS TEST 181 PRINT COMMUNICATIONS TEST COMPLETE 182 END APPENDIX A ASCII COMMANDS TO THE MODULE The appendix describe
16. IM AS 25 20 REM USE A SERIAL POLL TO FIND OUT IF THE 995 IS STARTING FROM 21 POWER UP CONDITION 22 SPOLL 704 23 REM SKIP RESPONSE RECORD IF SERVICE REQUEST BIT NOT SET 24 IF A lt 64 THEN GOTO 30 25 ENTER 704 A IREM READ POWER UP RESPONSE RECORD 26 IF A lt gt 9500100007 THEN GOTO 30 REM TEST FOR POWER UP 27 DISP STARTING FROM POWER UP 28 REM IF POWER UP THEN SKIP INIT COMMAND 29 GOTO 40 30 REM IF NOT POWER UP INITIALIZE 995 31 OUPTUT 704 INIT 32 REM WAIT FOR INIT COMMAND TO COMPLETE 33 FOR I 1 TO 200 NEXT I REM WAIT LOOP 34 REM READ RESPONSE RECORD FROM 995 35 ENTER 704 A 36 REM 40 REM TEST COMMUNICATIONS FOR LOAD AND READ OPERATIONS 41 C 96000000069 REM CORRECT RESPONSE RECORD 42 OUTPUT 704 START REM SEND START COMMAND 43 ENTER 704 REM READ RESPONSE RECORD 45 REM DELAY LOOP TO ALLOW COUNTS TO ACCUMULATE 46 FOR 1 TO 200 NEXT I 47 OUTPUT 704 REM SEND STOP COMMAND 48 ENTER 704 REM READ RESPONSE COMMAND 49 IF A lt gt C THEN DISP ERROR IN STOP COMMAND 9 STOP 50 REM NOW READ ACCUMULATED COUNTS 51 OUTPUT 704 SHOW COUNTS REM ASK FOR COUNT VALUE FROM 995 52 ENTER 704 REM READ COUNT VALUE 53 DISP A REM VALUE PRINTED SHOULD MATCH COUNTER DISPLAY 54 REM READ SECOND RESPONSE RECORD FROM SHOW COMMAND 55 ENTER 704 A 56 REM END OF COMMUNICATIONS TEST 57 DISP END OF COMMUNICATIONS TEST 58 END 5 2 2 IBM PC Programming
17. M test failed Command syntax error 129 001 CCC 129 002 CCC 129 004 CCC 129 008 CCC 129 128 CCC 129 129 CCC 129 130 CCC 129 131 CCC 129 132 CCC Invalid verb Invalid noun Invalid modifier Invalid command data Invalid first data value Invalid second data value Invalid third data value Invalid fourth data value Invalid command Communications error 130 001 CCC 130 002 CCC 130 004 130 008 CCC 130 128 CCC 130 129 CCC 130 130 CCC 130 133 Execution error 131 128 CCC 131 129 CCC 131 130 CCC 131 131 CCC 131 132 CCC 131 133 CCC 131 134 CCC 26131135 CCC UART buffer overrun UART parity error UART framing error 488 communications error Input checksum error Input record too long Invalid input data record Aborted due to invalid handshake Invalid first command parameter Invalid second command parameter Invalid third command parameter Invalid fourth command parameter Invalid number of parameters Invalid data other than command data Could not load selected value Counters must be stopped but were not 24 B 3 DOLLAR RESPONSE RECORDS All other response records begin with the ASCII dollar sign character and another character to indicate the particular type of dollar record The following dollar response records are available A xxx DL A A record is used to transmit F xx lt DL gt
18. P 290 END Refer to Appendix A and exercise the remainder of the commands until you are familiar with the actions and responses This will prove valuable when using the commands in a computer program Remember that for every SHOW command two response commands must be read 5 1 2 BASIC Programming Connect the 995 to the computer via the RS 232 C cable refer to Section 4 for proper cable connections The following BASIC program for the IBM PC and compatible computers shows some of the programming methods between the 995 and the computer 5 2 INTERFACING TO THE IEEE 488 BUS Of the three choices of interface the IEEE 488 interface holds the greatest potential for misunderstandings This section on programming the 488 will hopefully help smooth the interfacing The two computer systems discussed in this section are the Hewlett Packard and the IBM PC compatibles For other computers there should be enough information included to allow interfacing to the Model 995 The major difference between the Hewlett Packard computers and the IBM PC compatibles is the fact that Hewlett Packard includes software drivers in the high level languages but on the IBM compatibles the interface circuitry and the software drivers to Interface to the IEEE 488 bus must be installed in order to complete the working system The most important aspect of interfacing to the IEEE 488 bus is ensuring that the address switches in the 995 are set c
19. Printed in U S A Model 995 Dual Counter Operating and Service Manual ORTEC Part No 736770 Manual Revision G 0505 Advanced Measurement Technology Inc a k a ORTEC a subsidiary of AMETEK Inc WARRANTY ORTEC warrants that the items will be delivered free from defects in material or workmanship ORTEC makes no other warranties express or implied and specifically NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ORTEC s exclusive liability is limited to repairing or replacing at ORTEC s option items found by ORTEC to be defective in workmanship or materials within one year from the date of delivery ORTEC s liability on any claim of any kind including negligence loss or damages arising out of connected with or from the performance or breach thereof or from the manufacture sale delivery resale repair or use of any item or services covered by this agreement or purchase order shall in no case exceed the price allocable to the item or service furnished or any part thereof that gives rise to the claim In the event ORTEC fails to manufacture or deliver items called for in this agreement or purchase order ORTEC s exclusive liability and buyer s exclusive remedy shall be release of the buyer from the obligation to pay the purchase price In no event shall ORTEC be liable for special or consequential damages Quality Control Before being approved for shipment each ORTEC instrument must pass a stringent s
20. R gt TEST 23 Description Places the 995 in the Terminal mode so that every character received is echoed to and displayed on the terminal Causes the 995 to perform certain self test routines Only the ROM and RAM self test are implemented APPENDIX B RESPONSE RECORDS FROM THE 995 MODULE The 995 Dual Counter Timer sends various types of information to the controlling terminal or computer This appendix describes the types of responses the module makes to the various commands The operator must be familiar with the concept of a record that is a continuous stream of characters with a special character such as the ASCII carriage return or line feed making its end B 1 DELIMITING CHARACTERS The end of a record transmitted between two devices must be marked by a special delimiting character The record delimiter for communications with the 995 module is either a carriage return or a line feed character or both as follows INPUT from either RS 232 C or IEEE 488 Either a carriage return or a line feed character will be accepted OUTPUT to IEEE 488 A line feed character is always used OUTPUT to RS 232 C Either a carriage return or the two character combination of a carriage return and a line feed may be appended to a record transmitted over the RS 232 C interface B 2 PERCENT RESPONSE RECORDS This type of record is called a percent record because it always begins with the ASCII percent 96 character A p
21. V Supply 1 Remove both side panels 2 Mount the small L shaped bracket to the left lower module bar with two flathead screws provided Use the third and fifth holes in the module bar counting from the rear of the module 3 Unplug the connector going to the Transistor mounted on the rear panel 4 Slidethe Power Supply chassis into the module and align the two holes in the top of the chassis with the two holes on the mounting bracket Insert the two roundhead screws provided to secure the chassis to the mounting bracket 5 Using the remaining two flathead screws secure the chassis to the right module bar through holes three and five counting from the rear 6 Connectthe power supply to the module using the connector that previously went to the power transistor on the PWB side of the rear panel 7 The connector to the power transistor can be left disconnected or the power transistor and connector can be removed from the module 8 Replace the side panels and the installation is complete 5 PROGRAMMING THE 995 5 1 RS 232 C INTERFACE To become familiar with the 995 commands and response records it is suggested that a terminal be used This allows the operator to exercise the unit and view on the terminal display exactly what must be done inside a computer program to communicate with the 995 effectively A complete list of commands and responses is given in Appendix A of this manual 5 1 1 Terminal Operation The
22. ayed by repeatedly pressing the Display push button until the desired LED is illuminated GATE A single LED indicates that the entire instrument is enabled to count For the Gate LED to be illuminated the module must be placed in the Count mode either manually or via the interface option the Enable input must be above 3 V REMOTE A single LED labeled Rem indicates that the 995 is under computer control and all front panel controls are disabled This mode is set by the ENABLE REMOTE command 2 3 CONTROLS DISPLAY Push button selects the contents of Counter A or B for presentation in the 8 decade display Repeatedly pushing the button cycles the selection through the two choices as indicated by the A and B LEDs STOP This push button stops all sections of the instrument from counting RESET Depressing this button resets both counters to zero counts and turns off both overflow indicators When power is turned on to the module a Reset is automatically generated COUNT Pushing this button enables the counting condition for the entire instrument providing the Enable input is not held below 1 5 V and the preset value has not been reached THRESH ADJUST A and B Front panel mounted 25 turn trimpots to adjust the positive inputthresholds for Counters A and B The range is from 100 mV to 9 5 V Adjacent test points provide the TTL logic signal outputs from the discriminators to facilitate adjustment using an oscilloscope
23. been powered up a power up response record will be waiting to be read A serial poll ibrsp command should confirm that the 995 is asserting the service request SRQ line on the bus DEV4 ibrsp 100 CMPL POLL OX40 DEV4 The second line shows the content of the status registers In this case it shows that the command was completed by the interface adapter The results of the poll OX40 show that the service request was being asserted by the 995 40 hex is bit 6 of the serial poll status byte set to a 1 Next read the power up response record from the 995 This is done with the command ibrd xx where xx is the number of bytes to be read This number must be as large as or larger than the number of bytes expected Most response records from the 995 will be 11 bytes long including the line feed terminator One exception is the contents of the counters in the SHOW_COUNTS command which is 19 bytes long Others may be shorter than the 11 bytes Appendix B DEV4 ibrd 12 2100 END CMPL COUNT 11 25 30 30 31 30 30 30 30 001000 37 30 0A 70 DEV4 In the above example the second line is the status register contents the third line is the number of bytes transferred by the 995 module to the computer the fourth and fifth lines show the characters transferred with the hexadecimal value on the left and the ASCII characters on the right Now the 995 is ready to accept commands from the computer The next example send
24. ctions To install the IEEE 488 GPIB interface 1 Remove the left side plate from the module If the optional power supply is not already installed skip to step 5 2 Remove the right side panel 3 Remove the two screws holding the optional power supply to the bottom right module bar 4 Remove the two screws on the top of the power supply chassis which secure it to the bracket mounted on the bottom left module bar and move the power supply chassis out of the module 5 On the interface board set the switches to the desired positions using Table 5 Set switch 7 to Counter Only 6 Install the interface board into the module sliding the IEEE 488 GPIB connector through the slot in the rear panel of the module first and align the 40 pin connector on the back of the board with the pins provided on the counter board Use care to insure proper match up of connector and pins 7 Install the two mounting screws into the standoffs provided on the counter board 8 Reinstall the power supply chassis if one is present 9 Replace side panels and installation 15 complete 4 3 PRINT LOOP INTERFACE MODEL 99X 3 With this interface the 995 can be included in a print loop with the other counters and timers from ORTEC Up to 50 counters can be included in a counting system with one controller such as the Model 879 Buffered Interface providing the interface from the loop to a computer or printout device A four pole DIP switch
25. ctors each time the contents of the corresponding counter change from 99 999 999 to 0 The output signal can be used as the input to another counter to increase the total counting capacity beyond eight decades 3 6 OPERATION To monitor the data collected during a counting cycle press the Display Select until the LED representing the desired counter is lighted To start a counting cycle press the Stop push button then press the Reset push button and then press the Count push button The counting can be halted at any time by pressing the Stop push button If desired the cycle can be resumed from the point of interruption by pressing the Count push button without pressing Reset 4 OPTIONS FOR THE MODEL 995 There are three interfaces available for the Model 995 to facilitate its integration into a system environment 1 the RS 232 C Serial interface which includes a 20 mA current loop circuit 2 the IEEE 488 GPIB interface 1978 standard digital interface bus and 3 the ORTEC standard print loop interface Each of these interfaces is a separate plug in card which is easily installed in the field For bin and power supplies that do not provide the 46 V needed for the logic circuitry used int the 995 and an Internal 6 Supply is available This option is field installable and delivers regulated 5 V directly to the integrated circuits on the PWB 4 1 RS 232 C INTERFACE MODEL 99X 1 This serial communications int
26. device in the system REN Remote Enable A bus management line used to select either local or remote control of each device EOI End of Identify The fifth bus management line used to indicate the end of a multiple byte transfer sequence This line is asserted with the last byte of a data record The IEEE 488 GPIB interface is a separate PWB that plugs into the 995 counter board and is held in place with two screws The connector containing the signals for bus communications is mounted to the board and is accessible through the rear panel of the 995 The placement of the connector is in accordance with the Standard NIM Digital Bus NIM GPIB with pin 1 of the connector to the top of the module When power is applied to the 995 a series of self test routines is executed to test certain parts of the module A response record is created to show the results of the tests This response record must be read by the bus controller before the 995 will accept any command A service request SRQ is issued to notify the controller that service is required before commands can be accepted Commands sent to the 995 must be terminated with ASCII carriage return and line feed characters For every command received by the 995 a response record is returned and must be accepted by the controller before another command can be issued In case of a SHOW command to the 995 two response records must be read by the controller All response records f
27. dition the following symbol may appear on the product N ATTENTION Refer to Manual AN DANGER High Voltage Please read all safety instructions carefully and make sure you understand them fully before attempting to use this product vii SAFETY WARNINGS AND CLEANING INSTRUCTIONS DANGER Opening the cover of this instrument is likely to expose dangerous voltages Disconnect the instrument from all voltage sources while it is being opened WARNING Using this instrument in a manner not specified by the manufacturer may impair the protection provided by the instrument Cleaning Instructions To clean the instrument exterior e Unplug the instrument from the ac power supply e Remove loose dust on the outside of the instrument with a lint free cloth e Remove remaining dirt with a lint free cloth dampened in a general purpose detergent and water solution Do not use abrasive cleaners CAUTION prevent moisture inside of the instrument during external cleaning use only enough liquid to dampen the cloth or applicator e Allow the instrument to dry completely before reconnecting it to the power source i 8 2 I EGER DUAL COUNTER ORTEC MODEL 995 DUAL COUNTER 1 DESCRIPTION The ORTEC Model 995 Dual Counter incorporates two 8 decade counters and an 8 decade LED display which offers instantaneous visual readout of the full contents of Counter A or B even in a dimly lighted r
28. e same procedure and ORTEC will provide a quotation Damage in Transit Shipments should be examined immediately upon receipt for evidence of external or concealed damage The carrier making delivery should be notified immediately of any such damage since the carrier is normally liable for damage in shipment Packing materials waybills and other such documentation should be preserved in order to establish claims After such notification to the carrier please notify ORTEC of the circumstances so that assistance can be provided in making damage claims and in providing replacement equipment if necessary Copyright 2005 Advanced Measurement Technology Inc All rights reserved ORTEC is a registered trademark of Advanced Measurement Technology Inc All other trademarks used herein the property of their respective owners 5 eiconsectet etos ol at i SAFETY INSTRUCTIONS AND SYMBOLS hn vi SAFETY WARNINGS AND CLEANING INSTRUCTIONS ssssssssesse n vii DESCRIPTION Tir tenet eret arate OL op deat whale di Dub ient op alee a di 1 2 SPECIFICATIONS 2 tener t Ree eas Ere eren d eer bee Re es 2 271 PERFORMANCE o ect reme A Dad me Dey RU TR RE Red ed 2 2 2 INDICATOR SA INO teenie Leh OCIO pad EA PEAG UE 2
29. e the two screws on the top of the power supply chassis which secure it to the bracket mounted on the bottom left module bar and move the power supply chassis out of the module 12 5 On the interface board set the switch to the desired position Master Slave or Normal 6 Set both W1 W2 jumpers for models 994 and 995 to the Dual position and for Models 996 and 997 to the SINGLE position 7 Install the interface board into the module sliding the PRINT LOOP connector through the slot in the rear panel of the module first and align the 40 pin connector on the back of the board with the pins provided on the counter board Use care to ensure proper match up of connector and pins 8 Install the two mounting screws into the standoffs provided on the counter board 9 Reinstall the power supply chassis if one is present 10 Replace side panels and complete installation 18 4 4 INTERNAL 6V SUPPLY OPTION MODEL 99X 4 This option is available for systems that do not have a bin and power supply containing a 6 supply It contains a transformer bridge rectifier and filter capacitor and uses the 117 V acavailable in the bin to generate the voltage and power needed for the logic circuitry contained in the 995 Although it replaces the function of the external 6 V supply it actually feeds 5 V power directly to the logic circuits on the PWB 4 4 1 Installation Instructions To install the optional Internal 6
30. ead The next statement shows a command to the 995 which includes parameters along with the command OUTPUT 704 SET DISPLAY 1 ENTER 704 A DISP A 266000000069 The above command should have changed the counter being displayed from A to B OUTPUT 704 SET DISPLAY 0 ENTER 704 A DISP A 26000000069 Counter A should now be displayed Connect a signal to Input A and type the following command OUTPUT 704 START ENTER 704 A DISP A 26000000069 16 The Gate light should now be On and the counter display should be accumulating counts OUTPUT 704 STOP ENTER 704 A DISP A 26000000069 The Gate light should go Off and the counting should stop OUTPUT 704 SHOW COUNTS ENTER 74 A DISP A XXXXXXXX 00000000 ENTER 704 A 266000000069 The XXXXXXXX in the first counter value should match the value shown in the display of the 995 Remember that for every SHOW command two records must be read Using the above examples and the information in Appendix A exercise the remaining commands to become familiar with the commands and response records The following is a sample BASIC program to demonstrate the commands and responses in a program 17 10 REM EXAMPLE PROGRAM FOR COMMUNICATING WITH THE 995 FROM 11 REM HP COMPUTER IT IS ASSUMED THAT AN ADDRESS OF 4 IS 12 REM SELECTED FOR THE 995 AND 7 IS THE NUMBER OF THE GPIB 13 REM INTERFACE IN THE COMPUTER 14 CLEAR REM CLEAR DISPLAY 15 D
31. ercent record is always transmitted after the execution of a command by the module it tells whether the command execution was successful and if not what type of error may have occurred Execution of a subsequent command cannot begin until the module has transmitted the percent response record terminating the current command Percent response records are fixed in length and have the following format the spaces are for readability and are not part of the record 96 XXX yyy ccc DL where 96 is the ASCII percent character the next three bytes xxx are a code for the general type of error the second three bytes yyy are the specific type of error and the final three bytes ccc are the checksum bytes Appendix A lt DL gt is an appropriate delimiting character Appendix B Records beginning with 001 002 and 004 can be OR ed together to obtain composite error indications That is the indication of power up and self test results must all be considered in order to determine what actually happened in the event of anerror For example see code below 005 002 could be derived by OR ing 001 with 004 power up just occurred and a self test failed with the 002 indicating that the ROM 1 test failed The following are percent response code assignments Command executed successfully 000 000 CCC Power up just occurred 001 000 CCC Power up self test failed 004 002 ROM test failed 004 008 RA
32. erface conforms to the EIA RS 232 C Standard and contains all the circuitry needed to communicate with most ASCII terminals and with most computers equipped with a serial communications port The connection is made with a standard 25 pin male D connector mounted directly to the interface printed wiring board PWB The connector is accessible through a slot in the rear panel of the 995 This connector is wired as a DTE data terminal equipment device as device as defined in the RS 232 C standard The 20 mA current signals are also included on this connector The signal connections are shown in Table 1 The signal names in upper case are the 20 mA current connections and the RS 232 C signal names are shown in lower case When this interface is connected to another DTE device such as a computer or terminal a null modem cable must be used to match the proper signals between the two devices These cables are available at most computer equipment suppliers or directly from ORTEC See Appendix C Optional Parts List The connections of the null modem cable are given in Table 2 The serial option is a full duplex asynchronous communications interface with a selectable baud rate from 50 to 19 200 The baud rate selection is made via a 4 position DIP switch located on the PWB Fig 2 The baud rate selected must match exactly the baud rate of the device to which the 995 20 mA CURRENT LOOP SELECTION PASSIVE ACTIVE ws ws
33. es representative or our Global Service Center Advanced Measurement Technology 801 South Illinois Avenue Oak Ridge TN 37831 Telephone 865 482 4411 www ortec online com ORTEC Part No 495 Power Supply 6V 638630 Cable Description 25 foot male female RS 232 C cable 641810 10 foot female female RS 232 C null modem cable 641830 C 75 3 meter length female female RS 232 C null modem cable 641820 Male male gender changer 641840 3 3 foot IEEE 488 cable 603620 13 2 foot IEEE 488 cable 641720 772 C1 print loop cable 462360 918 20 mA cable C19 609820 26 Bin Module Connector Pin Assignments for Standard Pin 0 03 8 16 17 18 19 20 21 22 3 V 3 V Spare Bus Reserved Bus Coaxial Coaxial Coaxial 200 V dc Spare 6 V 6 V Reserved Bus Spare Spare Reserved 12 V 12 V Spare Bus Reserved Bus Spare Spare Reserved Pin 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 Nuclear Instrument Modules per DOE ER 0457T Function Reserved Reserved Reserved Spare Spare 24 V 24 V Spare Bus Spare Spare 117 V ac Hot Power Return Ground Reset Scaler Gate Reset Auxiliary Coaxial Coaxial Coaxial 117 V ac Neutral High Quality Ground Ground Guide Pin Pins marked are installed and wired in ORTEC s Model 4001A and 4001C Modular System Bins
34. et of quality control tests designed to expose any flaws in materials or workmanship Permanent records of these tests are maintained for use in warranty repair and as a source of statistical information for design improvements Repair Service If it becomes necessary to return this instrument for repair it is essential that Customer Services be contacted in advance of its return so that a Return Authorization Number can be assigned to the unit Also ORTEC must be informed either in writing by telephone 865 482 4411 or by facsimile transmission 865 483 2133 of the nature of the fault of the instrument being returned and of the model serial and revision Rev on rear panel numbers Failure to do so may cause unnecessary delays in getting the unit repaired The ORTEC standard procedure requires that instruments returned for repair pass the same quality control tests that are usedfor new production instruments Instruments that are returned should be packed so that they will withstand normal transit handling and must be shipped PREPAID via Air Parcel Post or United Parcel Service to the designated ORTEC repair center The address label and the package should include the Return Authorization Number assigned Instruments being returned that are damaged in transit due to inadequate packing will be repaired at the sender s expense and it will be the sender s responsibility to make claim with the shipper Instruments not in warranty should follow th
35. first step whether interfacing to a terminal or computer is to ensure that the proper cables are available and that the data format and baud rate switches are set correctly Tables 3 and 4 The actual settings are not as important as ensuring that the 995 and the device to which it is connected are set to exactly the same conditions These conditions include the baud rate number of data bits parity conditions and number of stop bits Also set the 995 to the Recycle mode When these conditions have been satisfied connect the terminal to the 995 and apply power to the terminal Next apply power to the 995 A 96 response record should appear on the terminal screen showing the results of the self test at power up If all is well the response record should be 96001000070 Since the 995 powers up in the Computer mode the first command to the 995 should be to change to the Terminal mode This is done by typing TERMINAL and return on the keyboard These characters will not appear on the screen but the 96 response record 96000000069 and prompt should appear after the return Now any characters typed on the keyboard will be echoed to the terminal display Now that communication has been established try the following commands SHOW VERSION F0995 001 96000000069 gt SET DISPLAY 1 90000000069 2 SET DISPLAY 0 90000000069 2 START Start data collection 90000000069 gt This counting will continue until
36. he loop SYSTEM PRESET carries a signal to all modules in the system loop A preset condition stops data collection in all modules in the loop SYSTEM RESET carries a reset signal to all modules in the loop except any that may be set for Normal This signal originates in the Master module or in the Controller module GROUND provides a common ground reference to all modules in the system loop CONTROL carries a signal to indicate when the controller is in charge of the loop This signal is used to disable the Dwell function in any module in the loop that contains this function THIS MODULE FINISHED carries a signal to the next module in the loop arrives as PREVIOUS MODULE FINISHED to indicate its turn to transfer data has occurred THIS MODULE PRINTING carries a signal to the controller to indicate to the controller that the module presently transferring data has a number other than six decades of data to transfer to the controller This line is only driven during the module s turn to transfer data 4 3 1 Installation Instructions To install the PRINT LOOP interface in the ORTEC Models 994 995 996 or 997 1 Remove both side panels 2 Mount the small L shaped bracket to the left lower module bar with two flathead screws provided Use the third and fifth holes in the module bar counting from the rear of the module 3 Remove the two screws holding the optional power supply to the bottom right module bar 4 Remov
37. indicate mandatory settings Table 2 Null Modem Cable Connections Computer Pin Pin 994 No No Protective ground 1 lt gt 1 Protective ground Signal ground 7 lt gt 7 Signalground Transmit data 2 lt gt 3 Receive data Receive data 3 lt gt 2 Transmit data Request to send 4 lt gt 5 Clear to send Clear to send 5 lt gt 4 Request to send Data set ready 6 lt gt 20 Data terminal ready Dataterminal ready 20 lt gt 6 Dataset ready Table 3 Baud Rate Selection Baud Rate S4 S3 52 S1 50 On On Off On 75 On On Off Off 110 Off Off Off Off 134 5 On 150 Off On 200 On Off On Off 300 Off Off On Off 600 On Off Off On 1200 Off On Off Off 1800 Off On Off On 2400 On Off Off Off 4800 Off On On Off 9600 Off On On On 19200 On On On On 19200 On On On Off Table 4 Data Format Switch Position Off On 1 8 Data Bits 7 Data Bits 2 Enable Parity Disable Parity 3 Even Parity Odd Parity 4 2 Stop Bits 1 Stop Bit 5 6 Recycle Mode One Cycle Mode 7 Counter Timer Counter Only 8 Print Only Normal Mandatory settings The 99X 1 is shipped from the factory with the following settings Character length set to 8 bits Parity check and generation disabled Parity selection set to even Stop bit selection set for 1 Baud rate set for 9600 One Cycle mode selected OT deco za 7 Counter Timer selected Must be changed to Counter Only 8 NORMAL 4 1 1 20 mA Current Loo
38. instructions on how to select polarity The negative input threshold is fixed at 250 mV The positive input has a front panel threshold adjustment which is variable from 100 mV to 9 5 V A test point is included on the front panel to ease the adjustment process For positive logic pulses the threshold should be set well above the noise level of the input When used with a linear signal as the input the adjustment should be set just above the amplifier noise level INPUT A POLARITY Fig 1 Setting Polarity on W5 and W6 Select Counter Source ENABLE INPUT A gate input signal or dc level can be connected to the 995 through the Enable input on the front panel With no input to this BNC or with a voltage level gt 3 V the 995 is enabled to accept counts through the inputs on the front panel To disable the counters the input at this connector must be pulled below 1 5 V To do this the driving source must be capable of sinking 5 mA of current from the Enable input circuitry GATES A AND B INPUTS The individual A and B Gate inputs BNCs are located on the rear panel The input specifications are the same as for the Enable input but only affect the inputs of the respective counters 3 5 OUTPUT CONNECTIONS OVERFLOW OUTPUTS The counter overflow output signals are available through the BNC connectors located on the rear panel A slow positive logic signal nominally 5 V 20 us appears at the conne
39. l gt 3 V or open circuit allows counting lt 1 5 V inhibits counting input protected to 25 V The driving source must be capable of sinking 5 mA of positive current during inhibit 2 5 OUTPUTS OVFL A Rear panel output BNC connector provides a NIM standard slow positive logic signal each time Counter A overflows its 8 decade capacity The signal has a nominal amplitude of 5 V width 20 us OVFL B Rear panel output identical to Ovfl A except that it monitors overflows from Counter B 2 6 INTERFACES IEEE 488 When the IEEE 488 option board is plugged in it furnishes a rear panel standard IEEE 488 bus connector This 24 pin AMP CHAMP female connector allows the Model 995 to be controlled from a computer via the IEEE 488 bus The field installable option provides computer control of the following functions Count Stop Reset Remote selecting the displayed counter In the Remote mode the computer can disable all front panel controls Computer readout includes A and B counts which counter is being displayed and the overflow status for both counters SERIAL When the RS 232 C option board is plugged in it furnishes a rear panel 25 pin male D connector containing all signals for standard RS 232 C communications It also contains connections for 20 mA current loop communications The field installable RS 232 C option provides computer control of the following functions Count Stop Reset Remote and selectio
40. l be a response record waiting to be transferred to the computer This response record must be read before the 995 will accept commands First a serial poll will be performed to show the service request bit set With the computer operating under BASIC execute the following commands A SPOLL 704 DISP A 64 In the above statement 7 selects the GPIB interface in the computer and 03 is the address of the 995 on the bus This automatically conducts a serial poll of the 995 and assigns the status byte which is an 8 bit binary value to the variable A When the Variable A is displayed the value 64 is printed which is the decimal value of the 8 bit binary status byte Next the power up response record must be read before any commands will be accepted by the 995 ENTER 704 A DISP A 001000070 The ENTER statement reads the response record and assigns the input characters to the string variable A and the DISP statement prints the string to the screen In the following statements a command is sent to the 995 and the resulting responses from the 995 are read OUTPUT 704 SHOW_VERSION ENTER 704 A DISP A F0995 001 ENTER 704 A DISP A 000000069 In the above commands the firmware version installed in the 995 is asked for the string is assigned to A and displayed to the screen and the response record is read which indicates that everything is OK Remember for every SHOW command two records must be r
41. llation Instructions To install the RS 232 C interface 1 Remove the left side plate from the module If the optional power supply is not already installed skip to step 5 2 Remove the right side panel 3 Remove the two screws holding the optional power supply to the bottom right module bar 4 Remove the two screws on the top of the power supply chassis which secure itto the bracket mounted on the bottom left module bar and move the power supply chassis out of the module 5 Onthe interface board set the switches to the desired positions using Tables 3 and 4 to match the Model 995 and the device to which it will be connected 6 Install the interface board into the module sliding the RS 232 C connector through the slot in the rear panel of the module first and align the 40 pin connector on the back of the board with the pins provided on the counter board Use care to ensure proper match up of connector and pins 7 Install the two mounting screws into the standoffs provided on the counter board 8 Reinstall the power supply chassis if one is present 9 Replace side panels and installation is complete 4 2 IEEE 488 GPIB INTERFACE MODEL 99X 2 The IEEE 488 1978 standard bus is a byte serial bit parallel interface system established primarily forthe transfer of data and commands between the components of an instrumentation network The system is defined for no more than 15 devices interconnected by passive cabling
42. luded at the end of a command record It is used by the module upon reception of the command to verify that the record was transmitted without error The actual checksum is a byte obtained by adding all of the bytes of the record together as if they were 8 bit unsigned binary integers Unless otherwise started the checksum is to be transmitted as three ASCII characters representing the decimal equivalent of the binary integer decimal values range from 000 to 255 for 8 bit integers rather than a single binary byte The three checksum characters if present must be the last characters of the command record before the delimiter and must be separated from any data values by a comma If a data value is optional or not used a comma must precede the checksum for clarity 21 A 4 RESPONSE FROM THE MODULE After a command has been transmitted from the computer or terminal to the module no other command should be issued until a response record has been received from the module The response record indicates how the module responded to the previous command and that the module is ready to receive another command Appendix B explains how the computer or terminal operator should interpret the response records A 5 TIME UNITS USED INCOMMANDS Delay is the time the module will wait before processing or responding to a command from the operator or computer Delay values must be given in special time units of 0 25 ms The computer operat
43. munications interfaces and to commands from a host Places the 995 totally under the control of a host computer All front panel controls except the display select are disabled Enables the 995 to start a counting cycle on a group execute trigger command from the IEEE 488 bus This enables a number of counters to start simultaneously from a single trigger command Enables the 995 to stop a counting cycle on receiving a group execute trigger command from the IEEE 488 bus This is the complement to the ENABLE TRIGGER START command Causes the 995 to restart or initialize Same as a reset or power up Selects the counter whose contents will be displayed on the 995 front panel 7 segment LEDs The value will be either O or 1 for Counters A and B respectively Returns a 1 response record showing the status of the alarm The answer is in the form of a T for true for false Example IF Show the contents of Counters A and B of the 995 00000000 00000000 95000000069 Causes the 995 to send a response record showing the number of the counter whose contents are being displayed in the digits on the front panel 0 Counter A 1 2 Counter B A000245 000000069 Causes the 995 to send a record which shows the firmware version included in the 995 F0995 001 95000000069 Causes the 995 to start a counting cycle Stops the 995 from counting Letters TERMINAL TER TEST lt NUMBE
44. n of the displayed counter In the Remote mode the computer can disable all front panel controls Computer readout includes A and B counts and the counter currently displayed PRINT When the print loop option board is installed it furnishes a rear panel 14 pin AMP CHAMP female connector containing signals for the standard ORTEC daisy chain print loop operations This option is field installable When connected in a print loop with an ORTEC Model 777A Printer this option offers automated recycling of the counting and printing of all eight digits of A and B Counters along with any other counters in the print loop If the Model 777A is replaced with an ORTEC Model 879 Buffered Interface the print loop will have IEEE 488 and RS 232 C interface capability allowing the computer to start and stop the counting reset the module and read the contents of the A and B Counters 2 7 ELECTRICAL AND MECHANICAL DIMENSIONS NIM standard double width module 6 90 x 22 13 cm 2 70 x 8 714 in front panel per TID 20893 Rev WEIGHT e Net 2 4 kg 5 2 Ib e Shipping 3 7 kg 8 2 Ib POWER REQUIRED The basic Model 995 derives its power from a NIM bin furnishing 12 V and 6 V For NIM bins that do not provide 6 V an optional Internal 6 V Supply is available This option is field installable and draws its power from the 117 V ac lines in the bin With the Internal 6 V Supply installed the power requirements are as shown in column f
45. oom By adding field installable options considerably enhanced readout and control capabilities can be incorporated The full power of CCNIM Computer Controlled NIM can be obtained by adding the IEEE 488 option or the RS 232 C option These plug in boards yield computer control of all functions normally selectable from the front panel including start and stop count readout reset and selecting the displayed counter To eliminate accidental operator interference the computer can disable all front panel controls in the Remote mode Computer readout with either of the two options includes A and B counts and which counter is being displayed The IEEE 488 option also reads the overflow status for both counters Implementation of the IEEE 488 interface in the Model 995 is compatible with the NIM GPIB standard The CCNIM options can directly drive printers having RS 232 C or IEEE 488 ports For automated counting applications not requiring computer interfacing the standard ORTEC print loop function is available as a field installable plug in board In conjunction with an ORTEC Model 777A Printer this option offers automatic recycling of the counting and printing of all 8 digits of the contents of Counters A and B along with other counters in the print loop Instead of the 777A the ORTEC Model 879 Buffered Interface can be used to provide IEEE 488 and RS 232 C interfaces for all the counters in the print loop The Model 879
46. or must remember to enter the values for Delay properly A 6 CATALOG OF COMMANDS FOR THE 995 The commands on the following pages are arranged in alphabetical order Be sure to read the introductory material in this appendix before proceeding to the command descriptions CATALOG OF COMMANDS Minimum Command Letters CLEAR_ALL CL_ALL CLEAR_COUNTERS CL_COU CLEAR_EVENT_PRESET CL_EV_PR COMPUTER COMP DISABLE TRIGGER START DIS TRI STA DISABLE TRIGGER STOP DIS TRI STO Description Clears counters count preset event counter and event preset Clears all counters in the 995 module Resets the event preset register to zero Sets the 995 to the Computer mode where it does not echo any characters This is the complement to the TERMINAL command IEEE 488 operation only Disables the group execute trigger command from starting the counting cycle in the 995 IEEE 488 operation only Disables the group execute trigger command from stopping the counting cycle in the 995 Command ENABLE LOCAL ENABLE REMOTE ENABLE TRIGGER START ENABLE TRIGGER STOP INIT SET DISPLAY VALUE SHOW ALARM SHOW COUNTS SHOW DISPLAY SHOW VERSION START STOP Minimum Letters EN LOC EN REM EN TRI STA EN TRI STO INIT SET DISP SH ALA SH COU SH DISP SH VER STA STO 22 Description Places the 995 under local control i e the front panel controls The 995 will still respond to the com
47. orrectly and that the correct address is used when accessing the 995 in a program statement section 4 The other important consideration is to always read the response records from a previous command before trying to send another command otherwise the 995 will not respond Also when the 995 is powered up a series of self tests are performed and the results of these tests are included in a power up response record that must be read by the bus controller before any other commands are sent to the 995 Before attempting to connect the 995 to the computer the address switches should be checked to ensure that the proper address is selected and does not conflict with another module connected to the bus The 995 is shipped from the factory with the address switches set for 4 If more than one 99X 2 is connected to the bus the addresses of all but one will have to be changed The address may be set for any number from 0 to 31 however 0 is usually used for the controller in charge and 31 is used as the untalk and unlisten commands Section 4 2 Table 5 Another important point to consider when communicating with the 995 is the fact that the 995 always asserts the Service Request SRQ signal line on the bus when information is available for transfer This will be reset by conducting a serial poll or by reading the response record from the 995 When a serial poll is conducted a serial poll status byte is transferred to the computer This
48. ounter inputs can be achieved with the Gate A and Gate B inputs on the rear panel Interface connectors for the IEEE 488 RS 232 C and print loop options are also located on the rear panel Each counter has a rear panel output dedicated to signaling overflows Counting these overflows on another counter extends the counting capacity of the Model 995 The Model 995 derives its power from the 12 and 6 V supplies in a standard NIM bin with power supply For bins that do not contain a 6 V supply an Internal 6 Supply option is available This option is field installable and derives its power from the 117 V ac lines in the bin 2 SPECIFICATIONS 2 1 PERFORMANCE COUNT CAPACITY 8 decades for counts ranging from 0 to 99 999 999 in each of 2 counters MAXIMUM COUNTING RATE 100 MHz for negative inputs 25 MHz for positive inputs POSITIVE INPUT DISCRIMINATOR Threshold variable form 100 mV to 9 5 V with a 25 turn trimpot PULSE PAIR RESOLUTION 10 ns for negative inputs 40 ns for positive inputs 2 2 INDICATORS COUNTER DISPLAY 8 digit 7 segment LED display with leading zero suppression OVERFLOW INDICATORS LED indicators labeled Ovfl A and Ovfl B illuminate when the corresponding A or B Counter exceeds its capacity of 8 decades The indicator remains on until a reset is generated DISPLAY 2 LEDs labeled A and B indicate the information being displayed in the counter display Counter A or Counter B may be displ
49. our and are not applicable in column three Power Requirement Table 12V Basic Model 995 20 mA 995 plus IEEE 488 option 30 mA 995 plus RS 232 C option 45 mA 995 plus Print Loop option 20 mA 3 INSTALLATION Before inserting the Model 995 into the bin set the switches and jumpers for the desired operating conditions There are two jumpers inside the 995 that allow the operator to select the input polarity The left side panel must be removed to gain access to these jumpers Also if a communications interface is installed an 8 position dip switch must be set up correctly for the particular system to which it is connected 3 1 INPUT POLARITY SELECTION The 995 accepts and counts either fast negative logic pulses or slow positive logic pulses Determine the type of input pulses that will be furnished and set the internal PWB jumpers W5 and W6 to accommodate the type of pulses selected as shown in Fig 1 The 995 is shipped from the factory with the jumpers set for positive logic pulses When using the negative inputs the threshold pots should be set at gt 1 V This prevents any accidental triggering due to high ground currents present at counting rates of 100 MHz There are two important points to consider when supplying signals to the 995 1 A single pulse must cross the threshold level only one time Signals with overshoot or ringing will be counted more than once if such anomalies cause the signals to cross the th
50. p Output The 20 mA current loop operates in exactly the same way as the RS 232 C All switch selections apply equally to the 20 mA current loop communications The major difference in the two modes is the electrical characteristics of the signals The RS 232 C uses a change in voltage to transmit and receive data and the 20 mA current loop uses a change in current to transmit and receive data The current loop is optically coupled to the 995 and can be made to be either active current for the loop supplied by the 995 or passive current for the loop supplied by the connected device by changing a set of jumpers on the interface board Fig 2 The transmit and receive loops can be individually selected to be active or passive The Model 99X 1 is factory set at shipment with both the transmit and receive loops set for active The transmit and receive signals are included in the RS 232 C connector A special cable is needed when using the 20 mA current loop to connect the 995 to a computer or terminal The cable is available from ORTEC Appendix C Optional Parts List 4 1 2 Using the 99X 1 with a Printer By placing the PRINT ONLY NORMAL S2 8 to the PRINT ONLY position the 99X 1 interface will drive a printer with an RS 232 C interface directly This allows the module to generate a hard copy of the data collected without the need for command from a computer or keyboard When the interface is installed in a Counter Timer and the module i
51. reshold level 2 Single pulses with slow rise and fall times should be as clean as possible to prevent multiple counting As a slow signal approaches the threshold a small spurious noise pulse can traverse the threshold level and return causing an extra count to be added Internal Bin Supplied 6V Supply 12V 6V 117 Vac 110 mA 700 mA 75 mA 120 mA 1300 mA 105 mA 135 mA 1300 mA 105 mA 110 mA 950 mA 85 mA 3 2 GENERAL The Model 995 Dual counter operates on power furnished from a NIM standard bin and power supply such as the ORTEC 4001 402D Series If the bin and power supply does not contain a 6 V power supply an optional Internal 6 Supply is available for the 995 that derives its power from the 117 V ac supply in the bin 3 3 CONNECTION TO POWER Always turn off the bin power supply before inserting or removing any modules The power supply voltages should be checked after all modules have been inserted The 4001 402D Series has test points on the power supply control panel to permit monitoring of the dc voltages When power is applied to the 995 an automatic reset function clears the counters to zero and provides a standard set of start up conditions 1 display select set to Counter A and 2 counters in the Stop condition 3 4 SIGNAL CONNECTIONS COUNTER INPUTS The 995 accepts and counts either fast negative logic pulses or positive pulses with an amplitude from 0 1 to 10 V see Input Polarity Selection for
52. rom the 995 will be terminated with a carriage return line feed sequence with the EOI line asserted along with the line feed character Table 5 shows the switch configuration for address selection of the device on the bus Fig 3 The address selected is the total of the switches set to the Off position For example to select an address of 25 switches 1 1 4 8 and 5 16 should be set to the Off position 4 2 1 Using the 99X 2 with a Printer By placing the PRINT ONLY NORMAL S2 8 to the PRINT ONLY position the 99X 2 Interface will drive a printer with an IEEE 488 GPIB interface directly if the printer is addressable as a Listen Only device A bus controller is not needed for this operation but only one Counting module can be connected to the printer This allows the module to generate a hard copy of the data collected by controlling the module with the front panel controls When the interface is installed in a Counter Timer and started by the Count control each time the preset value is reached the data is automatically transferred to a printer If the Recycle mode is selected 52 6 Off the Counter data is cleared and anew cycle is started immediately If the One Cycle mode is selected 52 6 On the counter will halt until a reset is generated either by the front panel Reset switch or by the Dwell Time expiring at which time a new counting cycle will begin When the interface is installed in a Counter Only module a co
53. s precision integral discriminators on analog pulses For the latter application the TTL logic outputs of the discriminators are provided as test points on the front panel These outputs can be used to trigger an oscilloscope while viewing the analog signal at the counter input on the oscilloscope The oscilloscope trace will show the signals that are being counted by the Model 995 thus permitting a very selective adjustment of the threshold All the commonly used functions are conveniently accessible on the front panel Manual control of the Count Stop and Reset functions is via three push buttons The Gate LED is illuminated when the Model 995 is enabled to count The Display contains LED flags to indicate whether to warn when overflows have occurred in Counter A or Counter B and to advise when the front panel controls are disabled by the computer in the Remote mode The counting function of the entire module can be disabled by holding the Enable input below 41 5 V using an external signal source This condition also turns off the Gate LED Open circuit or gt 3 V at the Enable input allows the instrument to count if the Count mode has been activated The Interval output of another ORTEC timer can perform this functionto synchronize the Model 995 counting with the other timer The Interval outputs on all ORTEC timers provide nominally 5 V when counting and 40 5 V when counting is inhibited Independent gating of the A and B C
54. s started with the Count control each time the preset value is reached the data is automatically transferred to a printer If the Recycle mode is selected 52 6 Off the Counter data is cleared and anew cycle is started immediately If the One Cycle mode is selected S2 6 On the counter will halt until a reset is generated either by the front panel Reset switch or by the Dwell Time expiring at which time a new counting cycle will begin When the interface is installed in a Counter Only module a counting cycle is started by the front panel Count control When the counting cycle is stopped either by pressing the Stop control or by bringing the Master Enable or Gate input low the data which has accumulated in the counter will be transferred to the printer If the Recycle mode is selected the counter will be cleared and a new data collection Cycle started as soon as the counter is enabled either by the Count control if the counting was terminated by the Stop switch or by the Master Enable or Gate going high if the counting was stopped by this signal If the One Cycle mode is selected the counter will continue counting from the point of interruption without being reset when reenabled to count When power is applied to the module the model number of the module and the firmware version will be printed When any of the mode switches are changed the module must be powered up again before the changes are recognized 4 1 3 Insta
55. s a SHOW_VERSION command to the 995 that will cause the 995 to send the version of firmware installed in the module The n characters in the command cause the computer to send a line feed new line character along with the command This must be included before the 995 will execute the command 18 DEV4 ibwrt show_version n 100 CMPL COUNT 13 DEV4 Now read the version number DEV4 ibrd 12 2100 END CMPL COUNT 11 24 46 30 39 39 35 2D 30 F0995 0 30 31 0A 01 DEV4 Now read the response record DEV4 ibrd 12 2100 END CMPL 25 30 30 30 30 30 30 30 0000000 36 39 0A 69 DEV4 Connect a signal source to input A and type the following command DEV4 ibwrt start n 100 CMPL COUNT 6 DEV4 ibrd 12 2100 END CMPL COUNT 11 DEV4 The Gate light should be On and the counter display should be advancing DEV4 ibwrt stop n 100 CMPL COUNT 5 DEV4 ibrd 12 2100 END CMPL COUNT 11 25 30 30 30 30 30 30 30 0000000 36 39 0A 69 DEV4 The counting should be stopped and the Gate light should be Off The next command asks for the counter contents with the SHOW COUNTS command 19 DEV4 ibwrt show_counts n 100 CMPL COUNT 12 DEV4 ibrd 20 2100 END CMPL COUNT 19 30 30 30 3X 3X 3X 3X 3X 000XXXXX 3B 30 30 30 30 30 30 30 0000000 30 3B 0A 0 DEV4 ibrd 12 2100 END CMPL COUNT 11 25 30 30 30 30 30 30 30 960000000 36 39 0A
56. s the ASCII command format used by the 995 module Note When controlling the module from a terminal lower case letters typed at the terminal are converted to upper case by the module before echoing the characters to the terminal and evaluating the command A 1 COMMAND WORDS A command consists of words separated by underscores The first word of the command is a verb The second and third words are not always used and are called nouns and modifiers respectively The following is a typical command ENABLE_TRIGGER_START In the preceding command ENABLE is the verb and TRIGGER is the noun and START is the modifier Only enough letters of a word to make it unique four letters is always sufficient need be used in a command The preceding command could thus be abbreviated to 5 A 2 DATA VALUES Some commands need to include data values Such values must be separated from the keywords by one or more spaces The data is also sent as ASCII characters and if more than one parameter is included in the value the parameter values must be separated by commas The following is a command with data values SET_DISPLAY 1 In the preceding command the module is told to select Counter B for display In the command descriptions given in this appendix the following notation is important lt gt encloses a required value encloses optional value CHECKSUMS checksum may optionally be inc
57. thru 5 of switch 1 are used for the address selection Table 5 Table 5 Address Configuration Switch Position Off On 1 Address 1 Address 0 2 Address 2 Address 0 3 Address 4 Address 0 4 Address 8 Address 0 5 Address 16 Address 0 6 Recycle Mode One Cycle Mode 7 Counter Timer Counter Only 8 Print Only Normal Mandatory settings The following are descriptions for the 16 bus lines defined in the IEEE 488 bus DIO 1 THROUGH DIO 8 DATA INPUT OUTPUT These bidirectional lines are used to transfer data between devices Data is asynchronous and generally bidirectional The lines carry either data or address information depending on the state of the ATN line DAV Data Valid One of the three transfer control lines used to indicate that data is available on the DIO lines NRFD Not Ready For Data Another transfer control line used to indicate that all devices are ready to accept data NDAC Not Data Accepted The third transfer control line that indicates the acceptance of data by all devices ATN Attention A bus management line used to indicate the type of data on the data lines When the ATN line is asserted DIO 1 8 carry address or commands When ATN is false the data lines carry only data IFC Interface Clear A bus management line which is used to place the system in a known state for system initialization SRQ Service Request A bus management line used to indicate a need for service by a
58. unting cycle is started by the front panel Count control When the counting cycle is stopped either by pressing the Stop control or by bringing the Master Enable or Gate input low the data which has accumulated in the counter will be transferred to the printer If the Recycle mode is selected the counter will be cleared and a new data collection cycle started as soon as the counter is enabled either by the Count control if the 004 91 0 a CHm 741158 asse 220720 ORTEC f HEROS 09 INTERFACE 3 S2 65 1 1 0 ADDRESS ADDRESS 2 2 0 ADDRESS ADDRESS 4 3 0 ADDRESS ADDRESS 8 4 0 ADDRESS ADDRESS 16 5 0 ADDRESS RECYCLE 6 ONE CYCLE couwrER TIMER 7 COUNTER ONLY 8 RS 232 C Fig 3 Address Selection of DIP Switch on the 99X 2 IEEE 488 Interface Board Asterisks indicate mandatory settings counting was terminated by the Stop switch or by the Master Enable or Gate going high if the counting was stopped by this signal If the one Cycle mode is selected the counter will continue counting from the point of interruption without being reset when reenabled to count When power is applied to the module the model number of the module and the firmware version will be printed When any of the mode switches are changed the module must be powered up again before the changes are recognized 4 2 2 Installation Instru
Download Pdf Manuals
Related Search