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Compiled SCPI Functions

1. F6232A Fig Figure 3 1 Embedded Controller Example Configuration Chapter 3 49 Program Listing Programming with Compiled SCPI Providing an Error Routine C SCPI allows for error trapping of instrument run time errors Every time a run time error is put into an instrument s error queue the cscpi_error function is called The cscpi_error function shipped does nothing You can however write your own cscpi_error function and link it into your main program You can also use the example error routine that s been provided in the usr hp75000 demos cscpi directory To use the example error routine do the following 1 Copy the cscpi_error c routine into your own working directory 2 Compile both your file and the cscpi_error c file 3 Link the files For example gcc g mthreads o exampl xample o cscpi_error o lescpi lsicl Now when you execute your program and a run time error is put into any instrument s error queue the new cscpi_error function will be called cscpi_error c This routine provides the SCPI error routine for run time errors Errors in the instrument s error queue are reported include lt cscpi h gt void cscpi_error INST sicl_inst int error_number char string 20 SYST ERR char result 255 cscpi_exe sicl_inst string strlen string result sizeof result printf ERROR s result exit 1
2. c_addr The address where the results of the serial poll are stored Any valid C expression which evaluates to an unsigned character pointer can be used The preprocessor does not check to make sure that the c_addr is an unsigned character pointer Comments e The c_addr parameter must evaluate to an unsigned character pointer e For MESSAGE configurations C SCPI uses the SICL ireadstb function See the SICL documentation for more information 108 Chapter 5 Compiled SCPI Command Reference INST_READSTB Example This example polls the HP E1411B and stores the results in the stb address location INST _DECL vm E1411B R main unsigned char stb INST_STARTUP INST_OPEN vm vxi 24 EADSTB vm amp Sstb Chapter 5 109 Syntax Parameters Compiled SCPI Command Reference INST_SEND INST_SEND The instrument send command sends the SCPI information in the cmd_string parameter to the instrument defined by the id parameter INST_SEND id cmd_string c_expr Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL INST_
3. send data to file must be 100 bytes INST_SEND dig DIG TRACE DATA blockl 3100 12345678901234567890123456789012345678901234567890 12345678901234567890123456789012345678901234567890 INST_SEND dig DIG TRACE DATA block2 3100 abcdefghijkilmnopgqrstuvwxyz012345678901234567890123 12345678901234567890123456789012345678901234567890 Chapter 3 61 Programming with Compiled SCPI Using C SCPI in the Interactive Mode Since the interactive functions allow you to enter the SCPI commands at run time you can write your program to prompt the user for a SCPI command at run time An example program using the cscpi_exe function is described in this section This example is stored in the usr hp75000 demos cscpi directory See Chapter 5 for examples of the other two interactive functions Equipment Needed Embedded VXI Controller HP VXI Mainframe HP E1326B or HP E1411B Digital Multimeter Program Description This program sets up and initializes the HP Multimeter It prompts the user for an address and loops prompting for SCPI commands The SCPI commands are parsed by the Controller and executed by the HP Multimeter When a null string is entered the loop is exited This program demonstrates how you can use the C SCPI execute function in an interactive mode See Chapter 5 for more details on the C SCPI execute call Program Listing example6 cs
4. 0 36 Contents 1 2 Using Compiled SCPI continued Throughput and the Overlapped Mode eee eeeceeeeeseeeneeeneeeenees Overlapped Command cee eecessesseeseceeeceeeeeaeeesecesecnseeeeeeeseesaes Using the Overlapped Mode 00 0 eeceeceeseeeccesseeeeeeeeeeeseeeaeesseeeneeeneees Controlling Overlapped Execution eee eeeseeeeeenecsneeeeceaeeeneens Programming for Efficiency ceeceeseesceeeeeseeeeeeeaeeeaeeesesenaeeneees 3 Programming with Compiled SCPI Looking at an Example System Configuration sses Providing an Error Routine 0 eee cee ceseeeseceseeeeeceseeeeeesseeeseeeaeeeaees Programming with a Scanning Multimeter oo eee eeeeeseceneeeeees Programming with an External File oe eseeesecneeeeeceeeeeneees Programming with a C SCPI Parameter List cece eeeeeseeereeeneees Storing Block Data in a Separate File The f Option Using C SCPI in the Interactive Mode 0 0 0 eeeeeeceseeesneeeeeeseeeneees Triggering with the HP Embedded Computer eee eeeeeeeeeees 4 Troubleshooting Compiled SCPI Resolving Compiled SCPI Preprocessor Errors eeseesceseeeeeees Resolving Compile and Link Errors eee eeceeseeseecnseceeecnaeeeseees Resolving Compiled SCPI Run Time Errors 0 eee eeseeseeeneeeneees Usine GNU Debug ter wincisi ee nei adil eile ees Trapping Errors with CSCpi_error ceeeeseeeeeeseeesecencecnseceseceaeeeneens 5 Compiled SCPI Command Reference INST CE
5. INST_QUERY vm IDN Ss addrloc indicates that the result of the IDN command is a string because of the 3s The contents of this parameter are currently ignored for REGISTER configurations however it is good practice to include a format specifier in case you change toa MESSAGE configuration c_expr The expression that is used if a format specifier appears in the cmd_string parameter Any valid C expression can be used The preprocessor does not check to make sure it is the same type as the format specifier c_addr The address where the results of the instrument query is stored Any valid C expression which evaluates to an address can be used The preprocessor does not check it The address location should be of the same type as the response If a string is returned only non quoted strings are returned See Appendix A Online Documentation for details on finding query command response types c_addr The address if more than one result is returned from the query For example if you have SYST ERROR as the SCPI command two items are returned the error number and the error message INST_QUERY vm SYST ERR amp err_num err_msg Chapter 5 105 Comments Compiled SCPI Command Reference INST_QUERY e Multiple SCPI commands can be combined in the cmd_string parameter As with SCPI these commands are separated by semicolons
6. Compiled SCPI Software Installation The C SCPI software is part of an entire software collection consisting of LynxOS SICL C SCPI and Free Software Foundation code It is pre installed on your controller at the factory If you have had a problem with C SCPI or have accidentally removed some of the C SCPI files you may be able to recover these files from the install media To do this connect a SCSI CD ROM to the embedded controller insert the install CD and mount the file system For example mount dev sd974 3 mnt Then you can compare files in the mnt directory with files on your hard disk See the LynxOS manuals for more information on Lynx commands If you find that you need to reinstall the entire software system please refer to the HP E6237A VXI Pentium Real Time Controller manual for instructions 138 Appendix B Compiled SCPI File Structure Compiled SCPI File Structure This appendix provides a description and diagrams of the directory structure for the C SCPI software C SCPI Directories This section lists the directories and subdirectories with a brief description of each usr hp75000 usr hp75000 bin usr hp75000 csepi usr hp75000 demos usr hp75000 demos cscpi Main Directory for HP Compiled SCPI Software C SCPI utilities files used to build C SCPI software demos for HP 75000 family of products example programs used in the C SCPI manual set Other Directories These are ot
7. This is a C SCPI example of using the interactive mode The program is written to prompt the user for the SCPI command The command is then executed using the cscpi_exe function include lt stdio h gt include lt stdlib h gt include lt string h gt include lt cscpi h gt define LENGTH 1000 maximum length of SCPI command amp result INST_DECL vm E1411B REGISTER declaration for voltmeter main char command LE string variable for SCPI command char result LE 7 string variable for result x Continued on Next Page 62 Chapter 3 Programming with Compiled SCPI prompt user to enter logical address of multimeter puts Enter the logical address of the vm for example Nayi 24 nl gets command INST_STARTUP start operating system INST_OPEN vm command xinitialize multimeter if 0 returned open failed and print message if vm fprintf stderr vm at s failed to open n command exit 1 loop to enter SCPI commands for printf Enter a SCPI command for the multimeter Hit return to exit n while gets command loop until get a nonzero size gt gets may terminate on interrupt if command caused by the command break result 0 0 clear result string C SCPI call to execute the SCPI command cscpi_exe
8. For example RST MEAS VOLT AC is a common command RST linked with a SCPI command MEAS VOLT AC separated by a semicolon e The cmd_string parameter must be a quoted string and the SCPI command can not be a variable If you want to use a string variable use the cscpi_exe function call Since HP VXI instruments and the Controllers use different types of microprocessors the byte ordering is critical for 3b and a blocks SICL takes care of the MESSAGE configurations For REGISTER configurations however you must know what data size byte long etc the instrument expects See the C SCPI online documentation for the specific instrument and use the format specifiers to specify the size of the data type REGISTER configurations currently ignore the contents of readfmt This parameter is used by MESSAGE configurations to specify the format of the query result However you can still use this parameter in REGISTER configurations for program readability e When you send a SCPI command to a MESSAGE configuration you may have to include an end of line terminator n or if the instrument expects one e Online documentation is provided The documentation contains a SCPI quick reference commands not supported commands changed the SCPI command query response types a list of overlapping commands and ONSRQ restrictions Documentation is supplied for each su
9. Table E 2 cscpi_open_error Descriptions Error Most Likely Cause Description of Cause 0 No error has occurred No error has occurred He INST_STARTUP was not included in the See Resolving Compiled SCPI Run Time program before INST_OPEN Errors beginning on page 56 2 A mismatch between the declaration and the This occurs because the declaration made for open for the instrument s was detected by the the instrument INST_DECL did not match instrument driver the instrument that was opened in the INST_OPEN command This could also occur if one of the cards in a scanning multimeter is not supported 3 System is out of memory Check your system s resources Format of the address encountered with a This occurs when the software cannot multiple card instrument was incorrect Format understand an address of a multiple card INST_OPEN vm vxi nn nn instrument scanning multimeter or Digital Functional Test System for example 5 Invalid address was encountered See Program Description 2 of this section SICL iopen vxi nn call failed 6 SICL is not setup properly or not running SICL Determine if SICL is running on your system iopen vxi call failed See Other Causes of Program Description 2 of this section 7 or 8 SICL has encountered a resource problem or an Contact your local Support organization Internal SICL error has occurre
10. The parameter that defines the configuration type The configuration type can be one of the following keywords MESSAGE for HP IB or VXI message based configurations REGISTER for register based configurations If you have a register based card configured over HP IB the configuration type is MESSAGE 5 Syntax Parameters Parameter id driver type Comments T ST_DECL INST_EXTERN or INST_PARAM is required to declare the id parameter This declaration must be done before any use of the id parameter e See also INST_DECL and INST_PARAM 94 Chapter 5 Compiled SCPI Command Reference INST_EXTERN Example This example defines an external variable for the HP E1411B Multimeter Two program segments are shown one with the declaration and one with the INST_EXTERN to show vm declared in another file INST_DECL vm E1411B R extern void setup main INST_STARTUP INST_OPEN vm vxi 24 INST_EXTE E1411B R void setup INST_SEND vm RST See Chapter 3 Programming with Compiled SCPI for a more detailed example of this command Chapter 5 95 Syntax Parameters Comments Compiled SCPI Command Reference INST_ONSRQ INST_ONSRQ The instrument on service request command installs the function specified by the c_function parameter as a
11. void main Main Function char vm_id 40 vm E1411B R Commands INST_STARTUP INST_OPEN vm vxi 24 C SCPI Preprocessor INST DECI if vm 0 printf Open failed on vm n printf cscpi open error number d n cscpi_open_error 1 C SCPI Preprocessor INST_SEND vm RST n Commands INST_QUERY vm IDN n s vm id printf The id of this module is s n vm_id exit 0 Figure 1 1 getstrt1 cs C Program Chapter 1 9 Additional Information Getting Started with Compiled SCPI Running your First Compiled SCPI Program If you do not have an HP E1411B instrument installed in your C size mainframe you will need to change the following lines in the example program INST_DECL vm E1411B REGISTER change the instrument driver to your instrument E1411B __ E1330 E1446 E1414 etc check the instrument mode REGISTER _ REGISTER OR MESSAGE INST_OPEN vm vxi 24 change the logical address to your instrument s logical address Accessing C SCPI Online Documentation To access online documentation via manual pages type the following at the command prompt remember man is case sensitive man name where name is replaced by the following C SCPI Command e g INST_DECL Instrument driver e g E1411B For a complete list of instrument drivers available type the followi
12. HP E6237A Compiled SCPI for LynxOS User s Guide Notice The information contained in this document is subject to change without notice Hewlett Packard Company HP shall not be liable for any errors contained in this document HP makes no warranties of any kind with regard to this document whether express or implied HP specifically disclaims the implied warranties of merchantability and fitness for a particular purpose HP shall not be liable for any direct indirect special incidental or consequential damages whether based on contract tort or any other legal theory in connection with the furnishing of this document or the use of the information in this document Warranty Information A copy of the specific warranty terms applicable to your Hewlett Packard product and replacement parts can be obtained from your local Sales and Service Office U S Government Restricted Rights The Software and Documentation have been developed entirely at private expense They are delivered and licensed as commercial computer software as defined in DFARS 252 227 7013 Oct 1988 DFARS 252 211 7015 May 1991 or DFARS 252 227 7014 Jun 1995 as a commercial item as defined in FAR 2 101 a or as Restricted computer software as defined in FAR 52 227 19 Jun 1987 or any equivalent agency regulation or contract clause whichever is applicable You have only those rights provided for such Software and Documentation by th
13. Specifiers continued sd sf The d format indicates that an int is used for the numeric expression for the c_expr parameter For example int numbl 5 INST_SEND vm CONF VOLT DC d numb1 If acomma is present in the format specifier the c_expr is a pointer to an array of integers instead of a numeric expression The comma operator is immediately followed by a number indicating the size of the array The comma can be useful when you have a list of channels to close For example int list 5 101 102 103 104 105 INST_SEND sw CLOSE 5d list NOTE C SCPI requires that the comma operator s corresponding array contain the complete channel list In the C SCPI command above for example you cannot add another comma operator to specify more channels to be closed The format indicates that a float is used for the numeric expression for the c_expr parameter For example float numbl 5 2 INST_SEND vm CONF VOLT DC numbl If acomma is present in the format specifier the c_expr is a pointer to an array of floats instead of a numeric expression The comma operator is immediately followed by a number indicating the size of the array The comma can be useful to define a waveform for the HP E1340A Arbitrary Function Generator For example float Lists SAS LO 29 Ox O025 INST_SEND arb LIST VOLT 5f list NOTE C SCPI requires that the comma operator
14. 122 123 Index 3 C continued cscpi_exe_stream Command 33 124 125 cscpi_get_overlap Command 40 126 cscpi_open_error 74 77 148 cscpi_overlap Command 40 42 127 cscpipp 6 cscpipp Command 10 133 cscpipp Command 20 66 D Debugging 32 using GNU debugger 79 80 Defining C SCPI Commands header file 19 instrument declaration 19 initialization 19 programming commands 19 Determining Command Order overlapped mode 45 Disabling Interrupts 44 E Embedded Controller 13 configuration 49 external triggering 64 Enabling Interrupts 44 Errors compile and link errors resolving 69 73 compile errors 69 72 error messages 146 148 link errors 69 73 preprocessor errors resolving 66 68 run time errors 148 description 82 resolving 74 78 syntax errors 66 trapping with cscpi_error 50 81 83 119 troubleshooting 66 83 usage errors 67 68 Example Program error routines 50 getstrt1 cs 6 9 Index 4 Example Program continued programming with external files 53 55 with parameter list 56 58 with scanning multimeter 51 52 using f option 28 59 61 i option 30 interactive mode 62 63 Examples compile error 69 72 directory location 48 link error 73 programming with a parameter list 56 58 with a scanning multimeter 51 52 with an external file 53 55 run time errors 74 78 82 syntax error 66 system configuration 48 usage error 67 68 with cscpi_error 50 Ex
15. Chapter 2 23 Using Libraries Using Compiled SCPI e Compiling Linking in One Step You can also compile and link your program in one step To compile link in one step type the following at the command prompt gcc g mthreads o sourcel sourcel c lescpi lsicl Comments This will create the executable file sourcel For troubleshooting compile link errors see Chapter 4 Troubleshooting Compiled SCPI A library is a set of commonly used functions that have been gathered into one place The library functions are already assembled or compiled to object code They are referenced by the linker to create an executable file In addition to the C library you need the following libraries to compile your C SCPI programs cescpi The Compiled SCPI Library provides access to the instrument drivers for all SCPI commands Additionally it provides the instrument environment necessary to interface between your computer s operating system and the instrument drivers sicl The Standard Instrument Control Library provides a modular instrument communications library that works with a variety of computer architectures I O interfaces and operating systems By using this library C SCPI remains independent of Input Output machine specific information 24 Chapter 2 List compiler name Set compiler flags List Link editor name Set linker flags List object file s Define program name gt Define name of
16. The mthreads option causes the multi threaded versions of standard functions like malloc and printf to be used rather than the single threaded versions The I option searches the specified directory path for additional include files For troubleshooting Compile errors see Chapter 4 Troubleshooting Compiled SCPI 22 Chapter 2 Using Compiled SCPI From the C SCPI C Code ready for the Object Code ready for Executable Code Preprocessor Compiler to create an the Linker to create an ready to run source1 c object file executable code gt Compiler Linker Standard C Library T math library HP Standard Instrument Command Library SICL C SCPI Library Instrument Drivers Figure 2 4 Compile and Link Process e Linking During this step the linker takes the object file created during compilation combined with standard libraries plus other object files and libraries you specify and creates an executable file To link your program type the following at the command prompt gcc g mthreads o sourcel sourcel o lescpi lsicl Comments The csepi library must precede the sicl library when linking your program The o option creates an executable file called source rather than the default a out The 1 option is used to link in the Compiled SCPI library and the SICL library For troubleshooting Link errors see Chapter 4 Troubleshooting Compiled SCPI
17. example cs include lt stdio h gt include lt cscpi h gt extern void scpifile INST_PARAM vm E1411B R ECL vm E1411B R TARTUP PEN vm vxi 24 scpifile vm Each file must be run through the C SCPI preprocessor compiled and then linked When the first file scpifile cs is run through the C SCPI preprocessor with the i option the scpifile function is generated When the main program calls the function the instrument driver name specified when the preprocessor was run is used Chapter 2 31 Advantages of Using the Interactive Functions Using Compiled SCPI Interactive Functions Interactive Functions The interactive functions allow you to specify your SCPI command at run time instead of in your source code With other C SCPI commands you have to specify the SCPI command in the argument list For example INST_SEND id RST contains the SCPI command RST With the INST_SEND command the SCPI command must be in your program before the C SCPI preprocessor runs With the interactive functions however you can prompt the user to enter the SCPI command at run time Several advantages of using the interactive functions include the following e You can enter the SCPI command at run time instead of in your source code e You can use the interactive functions as a means of debugging your SCPI commands The only disadvantag
18. f option 27 28 59 61 g option 7 22 GDB software tool 79 I option 7 22 i option 29 31 iintrof 44 lintron 44 INST_CLEAR 88 89 INST_CLOSE 90 91 INST_DECL 92 93 Index 2 Commands continued INST_EXTERN 53 54 94 95 INST_ONSRQ 96 97 INST_OPEN 98 99 INST_PARAM 56 100 101 INST_QUERY 102 107 INST_READSTB 108 109 INST_SEND 28 110 115 INST_STARTUP 116 INST_TRIGGER 117 l option 23 make 25 26 man 10 132 135 mthreads option 7 22 non overlapping 40 o option 23 overlapped 40 preprocessor 27 quick reference 128 129 SCPI only files 29 31 Compiled SCPI advantages of using 12 command reference 86 129 description 13 directories 140 errors 146 148 file structure 140 141 getting started with 2 14 interactive functions 32 35 62 63 learning about 11 14 overlapped mode 36 46 overview 16 17 preprocessor command 27 programming with 48 64 running first program 6 10 software installation 138 structure on LynxOS 141 threads 144 throughput 12 14 troubleshooting 66 83 using 16 46 GDB software 79 80 in interactive mode 62 63 C continued Commands continued verifying system setup 4 5 your system 3 5 who should use 12 writing programs 144 Compiling c option 22 errors resolving 69 72 g option 7 22 I option 22 linking source code 22 24 mthreads option 22 programs 6 144 Configuration examples 48 requiring overlapped mode 37
19. readfmt c_expr c_addr c_addr Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_QUERY vm TST amp results sends to E1411B cmd_string The string constant containing the SCPI command s See the instrument s VXI User s Manual for information on the SCPI commands or see Appendix A Online Documentation For example INST_QUERY vm TST amp result where TST is the cmd_string Any SCPI parameter in the string can be expressed with a format specifier If a format specifier is used each c_expr parameter that follows contains the corresponding C expression This is similar to the format specifiers in the C printf function The following format specifiers are available for REGISTER configurations sda amp S Sa Sf Sr Ss Sb Each of these format specifiers is discussed on the following pages 102 Chapter 5 Compiled SCPI Command Reference INST_QUERY cmd_string Format Specifiers NOTE The format specifier must be the same type that the instrument expects If for example the instrument expects a float number you must use the f format spe
20. vm command strlen command result sizeof result if you have a result print it if result 0 printf Result s result printf DONE n exit 0 Note The char array returned for result includes a new line at the end of the array Therefore you do not have to include a new line when printing the results Chapter 3 63 Programming with Compiled SCPI Triggering with the HP Embedded Computer In order to use the external triggering on the HP Embedded Computer you must route the external trigger lines to the TTL trigger lines You must then edit your program to trigger from the TTL trigger lines instead of the external trigger lines See the ivxit rigroute command in the SICL documentation for information on redirecting the trigger lines 64 Chapter 3 Troubleshooting Compiled SCPI Syntax Error Example Troubleshooting Compiled SCPI This chapter provides a guide to troubleshooting errors that may occur when using Compiled SCPI software Examples of the most common errors are described This chapter includes the following Resolving Compiled SCPI Preprocessor Errors Resolving Compile and Link Errors Resolving Compiled SCPI Run Time Errors Using GNU Debugger Trapping Errors with cscpi_error Resolving Compiled SCPI Preprocessor Errors When executing the preprocessor command cscpipp you may get preprocessor syntax or usage errors These errors can occur from
21. vxi 24 25 26 can be used for a scanning voltmeter configuration The voltmeter is at logical address 24 and the switch cards are at logical addresses 25 and 26 If an HP IB instrument is used the hpibxx xx xx quoted string should be used with the first xx being the logical unit the second xx the primary address and the last xx the secondary address For example hpib7 23 1 can be used where 7 23 1 is the logical unit primary address and secondary address respectively 98 Chapter 5 Compiled SCPI Command Reference INST_OPEN Comments e This command sets REGISTER configured instruments to their power on state See the instrument s VXI user s manual for information on the instrument power on state INST_OPEN must be executed after the instrument declaration and before the system start up for example INST_DECL and INST_STARTUP This command must also be executed before any instrument command that uses id e If this command fails the id parameter is set to 0 It is good practice to check the id parameter before doing anything else For REGISTER configurations you can also check the cscpi_open_error global variable for more information See Chapter 4 Troubleshooting Compiled SCPI for information on checking this variable For MESSAGE configurations see the SICL igeterrno and igeterrstr e For MESSAGE configurations C SCPI uses the SICL i
22. 1 line 30 sourcel cs extern vm_conf instr_send vm vm_conf amp in_ FAD amp vm_dc struct long p1 3 out_ line 31 sourcel cs extern vm_read_q if instr_query vm vm_read_q void 0 amp out_ line 31 sourcel cs Ef HPSL_GENERIC out_pl formatter line 31 sourcel cs HPSL_GENERIC out_pl formatter amp vm_dc amp HPSL_GENERIC out_pl length void Figure 2 3 C CSPI Source Code and Preprocessor Translated Code Chapter 2 21 Using Compiled SCPI Compiling Linking your Code This section explains how to compile and link your source code to create an executable file When creating your executable file you can compile and link in one or two steps as described below For additional information on compiling and linking programs refer to your C compiler s manuals Figure 2 4 displays the compile and link process e Compiling During this step the C compiler converts the C source file s to an object file An object file contains binary code but it is not in executable form To compile your program type the following at the command prompt gcc c g mthreads sourcel c Comments The c option creates an object file called sourcel o The g option indicates to the compiler that the source should be compiled with information so a debugger may be used this is optional
23. Brackets within the Syntax description determine optional elements 2 Chapter 1 Hardware Requirements Getting Started with Compiled SCPI Verifying your Compiled SCPI System Verifying your Compiled SCPI System To ensure that you are ready to start programming your system using the Compiled SCPI software you should review the system check list for hardware and software requirements learning products verification of your system setup and how to run a simple program The following lists the steps in preparing for a successful experience Preparation Check List 1 Review System Components Hardware Requirements Software Requirements Learning Products 2 Verify your System Setup 3 Run your First C SCPI Program see Running your First Compiled SCPI Program on page 6 Define C SCPI Process Run the C SCPI Preprocessor Create Executable Code Execute your Program Access C SCPI Online Help Reviewing System Components This section lists the system components you should have upon receipt of your system The requirements for this system include hardware software and learning products or documentation The minimum hardware requirements for your system are as follows e HP Pentium embedded controller with minimum 1GB disk drive 16MB DRAM Chapter 1 3 Getting Started with Compiled SCPI Verifying your Compiled SCPI System Software The software requirements for your
24. Compiled SCPI Program Listing example3 cs This example shows how you can use a file of your own drivers for a specific instrument include lt stdio h gt include lt stdlib h gt include lt cscpi h gt define VM_ADDR vxi 24 define FUNCTION VOLT AC define RANGE 8 extern void E1411_func INST id char func extern void E1411 _volt_range INST id double range extern float E1411 read INST id main float answer INST_DECL vm E1411 R INST_STARTUP INST_OPEN vm VM_ADDR 1411 func vm FUNCTION E1411 volt_range vm RANGE answer E1411 read vm printf Answer f n answer Continued on Next Page Chapter 3 57 Programming with Compiled SCPI example3a cs This example is a file of drivers that can be preprocessed and used as a library of function calls from other C programs x include lt cscpi h gt Needed for INST commands This function can be used to specify the function of the x multimeter void E1411_func INST_PARAM id E1411 REGISTER char func INST_SEND id FUNC S func This function can be used to specify the voltage range of the multimeter void E1411_volt_range INST_PARAM id E1411 REGISTER double range INST_SEND id VOLT RANGE Sf range This
25. Online Documentation ceeseceseeeeeeeneeees 10 Learning About Compiled SCPI ceccceccceseeceeteceeneceaeeceeeeeeeeeeeeaeees 11 Advantages of Using Compiled SCPI eeeeeeeeereeseerererrsreeres 12 Compiled SCPE SY steM cs iine n a csceeeedie 13 Maximum System Throughput with Compiled SCPI 0 0 14 2 Using Compiled SCPI Overview Of C SCPDiisccissceueds iseecteisgacesieasusetognedccuuegeselavtesstesaeesieasense 16 Creating Source Codex iia nchsen arn asin a r iaie 18 Defining the C SCPI Commands 2 0 0 ceceeceeeeseeereeseeeeeseceseeeneees 19 Running the C SCPI Preprocessor ieee eecceseeeeeeeeeceeeeaeceseeeaeees 20 Compiling Linking your Code 0 ce ceseesceseceeeceeeeeneeeeneeeseeeseeeaeens 22 Executing Your Programm nsei ene anneanne ar a 25 Using Maketiles isc teitec ete n a n naaa 25 Preprocessor Options cites i eeielens teh Sateen dete EE EEAS 27 The Compiled SCPI Preprocessor Command eceeeeeseeeeeeeneeees 27 Storing Block Data in a Separate File The f Option 27 Using SCPI Only Files The i Option 0 eee eeeeestecereceeeeaeens 29 Interactive FUNCUONS sic cere sche ite hee cibe ede nen eshte teevees 32 Using Interactive FUNCTIONS eee eeseeteceseeeeeeseeceeeeeaeeeseeenaeeeaees 32 Programming with Interactive FUNCTIONS 0 0 0 eee eeeeseceteeeeeeeeeeeees 34 Overlapped Mode erk eresien anei ae a aea evens Metees hte E ara E aet 36 Determining if you Should use the Overlapped Mode
26. a switch The I O channels are then closed and an I O channel is opened for a scanning voltmeter with the switches configured as voltmeter cards See the HP E1326B E1411B 5 1 2 Digit Multimeter User s Manual for information on these configurations E1411B R E1460A R main INST_STARTUP INST_OPEN vm vxi 24 INST_OPEN sw vxi 25 26 PEN vm vxi 24 25 26 Chapter 5 91 Syntax Parameters Comments Compiled SCPI Command Reference INST_DECL INST_DECL Instrument declare creates a variable declaration for the instrument data pointer This variable can be declared a global variable in the mainline program or it can be declared a local variable in a function This command also designates the name of the instrument driver and the configuration type REGISTER or MESSAGE INST_DECL id driver type Parameter Description id The user variable name for the instrument This is where you declare the variable name for the instrument This variable name will be used by other C SCPI commands For example INST_DECL vm E1411B REGISTER assigns vm to the E1411B driver The parameter that defines the HP driver This parameter is a quoted string for example E1411B is the driver name for the HP E1411B Multimeter See the HP 75000 Family of VXI P
27. can be one of the following b pointer to an array of char 8 bits 1b pointer to an array of long int 32 bit words wb pointer to an array of short 16 bit words zb pointer to an array of float 32 bit floating point numbers Zb pointer to an array of double 64 bit floating point numbers 104 Chapter 5 Compiled SCPI Command Reference INST_QUERY cmd_string lt width gt The a format indicates that a binary FILE is used for c_expr Format size a lt width gt is either a number or an asterisk The number indicates Specifiers the number of elements to be sent and the indicates that the continued number is taken from the next parameter for example 31024a or a See INST_SEND for an example size determines the size of each element in the array size can be one of the following a binary file containing an array of char 8 bits la binary file containing an array of long int 32 bit words wa binary file containing an array of short 16 bit words za binary file containing an array of float 32 bit floating point Za binary file containing an array of double 64 bit floating point readfmt The format of the query result when using a MESSAGE configuration A format specifier is used in this location See the instrument s VXI user s manual for information on query response types See iscanf in the SICL manual for a description of available format specifiers
28. can be resolved by linking in the SICL library gcc mthreads o source2 source2 o lcscpi lsicl Error Message Undefined Symbol s instr_misc instr_query instr_send cscpi_open_error Resolution Determine if you have linked all the appropriate libraries your program needs This particular link error can be resolved by linking in the C SCPI library gcc mthreads o source2 source2 o lcscpi lsicl Chapter 4 73 Troubleshooting Compiled SCPI Where To Go For More Information For this type of error you should refer to the following 1 Running Your First Compiled SCPI Program in Chapter 1 or 2 Chapter 2 Using Compiled SCPI for information describing the compile and link process for C SCPI Resolving Compiled SCPI Run Time Errors Run time errors occur when executing the program s executable code This section describes some run time errors with descriptions of what to look for when trying to resolve them For more detailed information on debugging run time errors refer to Using GNU Debugger beginning on page 79 Additionally the instruments can generate errors Refer to the Trapping Errors with cscpi_error beginning on page 81 of this chapter or the instrument manual for these specific errors Error Message error INST_OPEN before INST_STARTUP open failed on vm cscpi open error number 1 Resolution Look in your program to determine where this message is printed Using Table 4
29. command is what causes the voltmeter trigger to occur However the INIT command is never reached Now if you turn overlapped mode ON this configuration should work Throughput and the Overlapped Mode Since the overlapped mode allows several commands to execute in parallel the system throughput can be higher This section describes why the throughput can be higher with overlapped mode ON and compares two C SCPI programming segments One program executes the commands sequentially and the other program executes the commands while in the overlapped mode Chapter 2 37 Using Compiled SCPI Overlapped Mode Comparing Two Both programs shown in Figure 2 5 are making the same measurement The Programs second program is in overlapped mode and the order of command execution is different See Programming for Efficiency on page 45 for a description of how to determine the order of your commands while using the overlapped mode The first program in Figure 2 5 uses sequential commands and sends the commands in a logical order for execution The controller waits until each command is done before beginning the next command These commands are executed sequentially The second program in Figure 2 5 uses the overlapped mode and sends all of the setup commands first If these commands are overlapping commands and sent to different instruments they are executed in parallel Once the setup commands are sent OPC commands are sent to make sure al
30. create your executable code you must run the C SCPI preprocessor on each file compile each file and then link the files together An example follows e Run the C SCPI Preprocessor cscpipp i E1411B scpifile cs gt scpifile c cscpipp example cs gt example c e Compile each file gcc gcc e Link the files g mthreads example c G c g mthreads scpifile c gcc g mthreads o exampl xample o scpifile o lcscpi lsicl Chapter 2 29 Example Programs scpifile cs Using Compiled SCPI Preprocessor Options This section shows two program segments The first is a file segment that has SCPI commands for the HP E1411B Multimeter The second program segment shows a main program that uses the first file which contains only SCPI commands The C SCPI i option is used with the first file to convert it into a C function of instrument sends The following program segment shows a file containing strictly SCPI commands for the HP E1411B Multimeter When this file runs with the i option a function called scpifile is generated same as the file name but without the extension RST CLR FUNC VOLT AC VOLT RANGE 8 30 Chapter 2 Using Compiled SCPI Preprocessor Options This program segment calls the function generated by the C SCPI preprocessor with the i option The instrument driver name that was specified with the i option is used as the pass parameter when calling the function
31. done the following 1 included the cscpi h header file to define type INST and 2 used the INST_DECL command to declare vm as type INST For this particular error the cscpi h header file was not included Chapter 4 69 Program Description Note sou res inclu inclu Troubleshooting Compiled SCPI rce2 cs set voltmeter to measure DC volts query for the ults and print the results de lt stdio h gt de lt stdlib h gt INST_D j loa floa INST ECL vm E1411B R ER numb1 2 0 vm_dc _ STARTUP INS exit OPEN vm Vvxi 24 0 Once you have resolved a compile error you MUST re run the C SCPI preprocessor Otherwise you will be compiling the same code you were before Error Message source2 cs In function main source2 cs 27 incompatible types in argument passing Resolution Look in your program on line 27 to determine the C SCPI command in error In this example the C SCPI command on line 27 is as follows INST_QUERY vm READ S vm_dc Using Chapter 5 Compiled SCPI Command Reference look up the INST_QUERY command and make sure you have set up the parameters correctly The INST_QUERY command expects the parameter for the result of the query to be an address Therefore this parameter must be a pointer type By placing the amp in front of vm_dc the results of the query will be placed in the address of
32. function can be used to read data from the multimeter float E1411 read INST_PARAM id E1411 REGISTER float result INST_QUERY id READ sf amp result return result 58 Chapter 3 Programming with Compiled SCPI Storing Block Data in a Separate File The f Option This programming example shows how you can use the f option with C SCPI to store block data in a separate file when the C SCPI preprocessor runs Using the f option reduces the size and compilation time of your C program See Chapter 2 for more information on the operation of the f option Equipment Needed Embedded VXI Controller HP VXI Mainframe HP E1330B 4 Channel Digital I O Program Description This program contains a function called load_t races The following SCPI command sends block data to a defined memory block number of bytes for length DIG TRACE DATA blockl 3100 location to number of byte store data to send When this program is preprocessed with the C SCPI f option the block data will be stored in a separate file example4 dat as shown below cscpipp f example4 dat example4 cs gt example4 c Chapter 3 59 Programming with Compiled SCPI In your program you must also open the file containing the block data and assign it to the cscpi_datafile FILE pointer for data retrieval This is shown in the following example Program Listi
33. in parallel OR You need an increase in system throughput See Controlling Overlapped Execution on page 43 for a description of programming techniques you can use 36 Chapter 2 Configurations Requiring Overlapped Mode Using Compiled SCPI Overlapped Mode Overlapped mode must be used when you have a configuration that requires SCPI commands for two or more instruments to be executed in parallel An example of this configuration might be if you want to scan several channels and make measurements on each channel where the instruments are set up as two separate instruments not a scanning voltmeter In this configuration a switch should close and wait for a voltmeter complete indicating that the voltmeter made its measurement Then the switch should close the next channel and the process should repeat However since the switch s INIT command is executed later in the program it will never be executed without overlapped mode ON This is because the voltmeter s measurement command is never finished The following program segment shows this configuration with overlapped mode OFF TRIG SOUR EXT CONF VOLT DC 0 825 MAX TRIG SOUR EXT ROUT SCAN 100 103 READ S result INIT Notice that the switch INIT is after the voltmeter READ Since the voltmeter requires an external trigger the READ command hangs because the INIT
34. overlapped mode in turned ON To find out which commands are overlapping and which are non overlapping see Appendix A Online Documentation for more information Using the Overlapped Mode To use the overlapped mode you simply place a C SCPI function call in your C program to turn the mode ON or OFF Default mode is overlapped OFF There are two C SCPI functions that are associated with the overlapped mode e cscpi_overlap e cscpi_get_overlap Each of these C SCPI functions is discussed in the sections following Make sure you read the Controlling Overlapped Execution on page 43 before attempting to use the overlapped mode 40 Chapter 2 Using Compiled SCPI Overlapped Mode Turning Overlapped The cscpi_overlap function turns the overlapped mode ON or OFF Mode ON or OFF Note By default this mode is turned OFF If you use a nonzero integer as the parameter the function turns overlapped mode ON A 0 turns overlapped mode OFF The parameter is of type int The following program segment shows how this function can be used in your C program ar variable type int int mode mode 1 4 1 turns overlapped ON r 0 turns overlapped OFF The 1 turns overlap ON 0 would indicate OFF See Chapter 5 for more information on the cscpi_overlap call cscpi_overlap mode Turning overlapped mode OFF does not guarantee that interrupts from incomplete commands are not generated If overlapping commands were executed w
35. program Where To Go For More Information To resolve these errors you will need to do one or more of the following 1 Use the error number from the cscpi_open_error variable to determine what type of problem you may have encountered 2 Check Table 4 1 to look up possible causes of cscpi_open_error 3 Run usr sicl bin ivxisc to determine if a resource manager problem occurred 4 Refer to SICL documentation for more information on resolving SICL errors 78 Chapter 4 Preparing to Use GDB Troubleshooting Compiled SCPI Using GNU Debugger This section provides a look at using the GNU debugger GDB is a software tool that allows you to step through your program when a run time error occurs For more detailed information on how to use GDB refer to Lynx Documentation When using GDB with your C SCPI programs you must compile and link your code using the debugger option g To Compile gcc c g mthreads source2 c To Link gcc g mthreads o source2 source2 o lescpi lsicl To Compile Link gcc g mthreads o source2 source2 c lescpi lsic Now you can use GDB to debug your program The following is a quick reference to some of the more useful gdb commands s to single step INTO a function n to single step OVER a function p to print a variable or expression p numb1 Woot p to change value of a variable p numb1 3 0 c to continue the program b to set a break
36. program _ gt Define name of source program Note Using Compiled SCPI Executing Your Program To execute your program type the following at the command prompt sourcel The result of executing this program is as follows DC Voltage is 1 86321 Using Makefiles Using make you can create a makefile to ease compiling and linking programs into one executable file For more information on how to use the make command refer to the Lynx manuals The following is an example of a simple makefile to compile link the C SCPI program sourcel cs gcc CFLAGS c g mthreads LD gcc LDFLAGS g mthreads OBJS PROGRAM sourcel o sourcel PROGRAM OBJS LD LIBS LDFLAGS OBJS LIBS lescpi lsicl 0o PROGRAM sourcel c sourcel cs cscpipp sourcel cs gt sourcel c sourcel o sourcel c a TAB must precede LD and cscpipp lines Chapter 2 25 Note Using Compiled SCPI This is a very simple makefile If your system has more than one C SCPI program then you may want to use the SUFFIX option of makefile This option tells the make command how to convert your C SCPI programs cs files into C programs c files There are a number of ways to do this The example below is one of those ways It tells make how to convert your cs files into c files without mentioning any specific program name Add the following two lines to your make
37. result INST_DECL vm E1411B REGISTER declaration for voltmeter main char command LENGTH string variable for SCPI command char result LENGTH string variable for result Continued on Next Page 34 Chapter 2 Note Using Compiled SCPI Interactive Functions prompt user to enter logical address of multimeter puts Enter the logical address of the vm for example Soya 2 aie No gets command INST_STARTUP start operating system INST_OPEN vm command initialize multimeter if 0 returned open failed and print message if vm fprintf stderr vm at s failed to open n command exit 1 loop to enter SCPI commands for printf Enter a SCPI command for the multimeter Hit return to exit n while gets command loop until get a nonzero size gets may terminate on interrupt if command caused by the command break result 0 0 clear result string C SCPI call to execute the SCPI command cscpi_exe vm command strlen command result sizeof result if you have a result print it if result 0 printf Result Ss result printf DONE n exit 0 The char array returned for result includes a new line at the end of the array Therefore you do not have to include a new line when printing the results Chap
38. s corresponding array contain the complete list In the C SCPI command above for example you cannot add another comma operator to specify more points in the waveform Chapter 5 111 Compiled SCPI Command Reference INST_SEND cmd_string s The s format indicates that a string expression without quotations is Format used in c_expr For example Spcailicls char count 5 MAX continued INST_SEND vm SAMP COUNT s count SS The s format indicates a string expression with quotations is used for c_expr The preprocessor will add the quotes For example char function 22 VOLT AC INST_SEND vm FUNC S function where the preprocessor puts VOLT Ac in the S location with quotes around it resulting in FUNC VOLT AC Sr The x format indicates an expression is used for c_expr For example char cond 04 or Q5 or Q6 INST_SEND d20 DIG TIM COND DEF r cond where cond is enclosed in parentheses Q4 or Q5 or Q6 112 Chapter 5 Compiled SCPI Command Reference INST_SEND cmd_string Format Specifiers continued lt width gt size b lt width gt size a Sb 1b Swb Szb SZb Sa Sla Swa za SZa The b format indicates that an array is used for c_expr lt width gt is either a number or an asterisk The number indicates the number of elements to be sent and the indicates that the numb
39. undeclared identifier In this example line 11 is as follows INST_OPEN vm Vxi 24 The INST_DECL command does not precede the INST_OPEN and therefore vm has not been declared Chapter 4 67 Troubleshooting Compiled SCPI Program Description source2 cs set voltmeter to measure DC volts query for the results and print the results include lt stdio h gt include lt cscpi h gt main float numb1 2 0 float vm_dc INST_STARTUP INST_OPEN vm Vxi 24 _DECL vm E1411B R Where To Go For More Information For C SCPI preprocessor usage errors you should check the following Chapter 5 Compiled SCPI Command Reference Chapter 2 Using Compiled SCPI 68 Chapter 4 Compile Error Examples Troubleshooting Compiled SCPI Resolving Compile and Link Errors Compile and link errors occur when executing the compiler and linker commands Once you have resolved compile or link errors you must re run the C SCPI preprocessor The compile link process is as follows compile gcc c mthreads source2 c link gcc mthreads o source2 source2 o lescpi lsicl Error Message source2 cs 5 parse error before vm source2 cs 5 warning data definition lacks type or storage class source2 cs In function main Resolution Determine if vm has been declared and defined as type INST Check your program to determine if you have
40. 1 look up the cscpi_open_error number displayed to determine what could have caused this problem 74 Chapter 4 Troubleshooting Compiled SCPI Table 4 1 Run time Errors Error Most Likely Cause Description of Cause 0 No error has occurred No error has occurred 1 INST_STARTUP was not included in the See following page for discussion program before INST_OPEN 2 A mismatch between the declaration and This occurs because the declaration made for the open for the instrument s was detected the instrument INST_DECL did not match the by the instrument driver instrument that was opened in the INST_OPEN command This could also occur if one of the cards in a scanning multimeter is not supported 3 System is out of memory Check your system s resources 4 Format of the address encountered with a This occurs when the software cannot multiple card instrument was understand an address of a multiple card incorrect Format instrument Scanning multimeter or Digital INST_OPEN vm vxi nn nn Functional Test System 5 Invalid address was encountered SICL See Program Description 2 of this section iopen vxi nn Call failed 6 SICL is not setup properly or not running Determine if SICL is running on your system SICL iopen vxi call failed See Other Causes of Program Description 2 of this section 7or8 SICL has encountered a resource problem Con
41. 35 OPC 44 46 Open Instrument Command 98 99 Other Documentation 150 Overlapped Commands 40 Index 6 O continued Overlapped Mode 36 46 completing system calls 44 configurations requiring 37 controlling overlapped execution 43 cscpi_get_overlap 40 126 cscpi_overlap 40 42 127 default mode 36 determining command order 45 determining to use 36 overlapped commands 40 parallel commands 36 programming for efficiency 45 46 throughput 37 39 using 40 42 OPC 44 46 P Parameter List programming with 56 58 Preprocessor command 27 error messages 146 148 errors resolving 66 68 f option 27 28 59 61 options 27 31 running the 20 21 Programming for efficiency overlapped mode 45 46 with a parameter list 56 58 with a scanning multimeter 51 52 with an external file 53 55 with compiled SCPI 48 64 with interactive functions 34 35 62 63 writing programs 144 Protecting System Calls iintroff 44 iintron 44 using OPC 44 Q Query Instrument Command 102 107 Quick Reference 128 129 R Read Status Byte Command 108 109 REGISTER Configuration INST_DECL 92 93 INST_EXTERN 94 95 INST_PARAM 100 101 Resolving compile and link errors 69 73 compiled SCPI preprocessor errors 66 68 run time errors 74 78 Reviewing C SCPI process 8 getstrtl cs program 9 Running C SCPI preprocessor 6 20 21 cscpipp 6 66 first C SCPI Program 6 10 runn
42. 411B R main INST_STARTUP INST_OPEN vm vxi 24 This example declares a local variable for the HP E1411B Since the voltmeter is declared in the function vm is only available in the function main mee INS ECL vm E1411B R _D INST_STARTUP _O INS PEN vm vxi 24 Chapter 5 93 Compiled SCPI Command Reference INST_EXTERN INST_EXTERN Instrument external creates an external variable reference for an instrument data pointer This command also specifies the instrument driver name and the configuration type REGISTER or MESSAGE This command is similar to instrument declare except that it declares a reference to an external variable INST_EXTERN id driver type Description The user variable name for the instrument This is where you declare the variable name for the instrument This variable name will be used by other C SCPI commands For example INST_EXTERN vm E1411B REGISTER assigns vm to the HP E1411B The parameter that defines the HP driver This parameter is a quoted string for example E1411B is the driver name for the HP E1411B Multimeter See the HP 75000 Family of VXI Products catalog for a list of available drivers available from your nearest HP Sales and Service Office or see Appendix A Online Documentation for more information
43. 5 Equipment Needed Program Description Programming with Compiled SCPI Programming with a C SCPI Parameter List This programming example shows how you can use the C SCPI INST_PARAM macro command to pass instrument identifications to functions See Chapter 5 for more information on the INST_PARAM macro command Embedded VXI Controller HP VXI Mainframe HP E1326B or HP E1411B 5 1 2 Digit Multimeter There are two separate files listed on the following pages The first file example3 cs represents the main program It uses the functions listed in the second file The second file example3a cs represents a file of functions that can be compiled separately from the main program This file uses the C SCPI INST_PARAM macro command to pass the instrument declaration to the functions More functions can be added to create your own drivers for the HP Multimeter Use the following steps to preprocess compile and link these programs E Run your C programs through the C SCPI preprocessor cscpipp example3 cs gt example3 c cscpipp example3a cs gt example3a c E Compile each file gcc gcc c g mthreads example3 c c g mthreads example3a c E Link the program files and cscpi_error file gcc g mthreads o example3 example3 o example3a o cscpi_error o lcescpi lsicl See Overview of C SCPI in Chapter 2 for more information on each of these steps 56 Chapter 3 Programming with
44. ASS exit 0 fail int test1 void define POINTS 10 f f loat a POINTS loat expected POINTS LeO 0 0 0 0 s 9 0 int fail Int 0 INST_QUERY M FAS VOLT 10 vm for i 0 i lt POINTS i if fabs a i expected i gt printf test point d failed i expected i alil fail 1 return fail 52 error number sd n cscpi_open_error run test using test1 function check to see if test passed or failed a simple test function number of points defin 1 0 5 0 xpected points 5 03 06 0 120 255 query for results and put into array 100 109 f amp a 01 measured f n Expected Sf Chapter 3 Equipment Needed Program Description Programming with Compiled SCPI Programming with an External File This programming example shows how you can use the C SCPI INST_EXTERN macro command to specify an external declaration This command works very similarly to the ANSI C extern command See Chapter 5 later in this guide for more information on the INST_EXTERN command Embedded VXI Controller HP VXI Mainframe HP E1326B or HP E1411B Multimeter This program uses the C SCPI INST_EXTERN and ANSI C extern commands Program example2 cs uses the INST_EXTERN command to declare the instrument id vm of the HP E1326B or HP E1411B M
45. B Multimeter This quick reference provides Command Descriptions Commands Not Supported Commands Changed Query Command Response Types Overlapping Commands ONSRQ Restrictions The SCPI commands are to b mbedded in HP Compiled SCPI commands For information on HP Compiled SCPI see the HP Compiled SCPI commands in manual pages or see the HP Compiled SCPI learning products For additional information on SCPI commands see the VXI User s Guide for the instrument Continued on Next Page 134 AppendixA Online Documentation SCPI COMMAND DESCRIPTIONS ABORt Place multimeter in idle state CALibration LFRequency 50 60 MIN MAX Change line reference frequency ONSRQ RESTRICTIONS The following commands can not be used in SRQ handlers which execute as an interrupt routine since they internally call iwaithandler if cscpi_overlap off ENS FUNC INIT READ MEAS for aperture 2 5 ms or with 1460 scanners The following commands may cause an SRQ handler to execute from an interrupt routine if SRO is enabled on the condition Any overlapped command followed by the OPC command with cscpi_overlap on An INIT READ or MEAS command with aperture 2 5 ms which sets the error bit from a timer too fast error Appendix A 135 Online Documentation Notes 136 AppendixA Compiled SCPI Software Installation
46. Controlling Overlapped Execution 43 Conventions Used 2 Creating Source Code 18 C SCPI creating executable code 6 directories 140 file structure 140 141 learning about 11 14 library 24 online documentation accessing 10 overview 16 17 preprocessor cscpipp 20 66 errors 66 68 running the 20 21 process 8 software installation 138 source code 18 22 24 structure on LynxOS 141 threads 144 using 16 46 in interactive mode 62 63 verifying system setup 4 5 your system 3 5 writing programs 144 C SCPI Commands command reference 86 129 defining 19 get overlap function 126 header file 19 instrument clear 88 89 close 90 91 declaration 19 92 93 execution 120 125 external 94 95 initialization 19 open 98 99 parameter 100 101 programming commands 19 query 102 107 read status byte 108 109 run time errors 119 send 110 115 service request 96 97 startup 116 trigger 117 macro commands 87 117 manual pages 133 overlap function 127 quick reference 128 129 C SCPI Functions 118 129 cscpi_error 119 cscpi_exe 120 121 cscpi_exe_fildes 122 123 cscpi_exe_stream 124 125 cscpi_get_overlap 126 cscpi_overlap 127 manual pages 133 cscpi Library 24 cscpi h Header File 19 cscpi_datafile 28 cscpi_drivers Manual Page 133 cscpi_error Command 50 81 83 119 advantages of using 81 example 83 linking 50 cscpi_exe Command 32 62 63 120 121 cscpi_exe_fildes Command 33
47. EA R e Sea ie wn eee Ati thease INST CLOSE conii eee Ps Se ee LeeLee INST DECI cre vacirnicia sient niiyt E E E leis hola datetna te Benton INST EE XCTERN osiensa elaine eect ined e TNS TA ONSR bi jecissccebhsiaceesstencectze ioubbuctieectabel ebatuactes senelebiaghenisdetestoc ates INST OPEN ran nn e a ead aes INST PARAM onerar aaa a aaa 100 INST QUERY oranana hens hare dia E E AE 102 INST READS UB Pine coe ti E E EA T aes aims 108 INST SEND aee aa a re ea a e A e ATR 110 INST STARPUP enina n a I ee 116 Contents 2 Contents 5 Compiled SCPI Command Reference continued TNS EATRIGGER 6s sscecesceigevesesoetbos cust iagsttal octeceMucchoete EEE AES EERE Aa o AR H KO tin fore rst ia eesihabe Sela ssin T CSEPI EKE r en E E p E ee ee eel Aoi Gaus tolietiy eh a aed Sepi EXE TIGES cscs zsstes ves etwas a a a a a E aisibeszesens CSCPLE LOK Cx Stred nn e e En EEE ATAS ANE ET nie CScpi_get overlappen its ken tatiadik iain neaceae sepi Overlap iia cckatiseiie ao Leo R Saw a R e Compiled SCPI Quick Reference 0 eee ceeceeeeeseeeneeceeeeseeceeeeeneeeaes A Online Documentation How To Use Manual Pages ieee ceecceseeeseeeneceeceeeeeseeeeeeeaeeeaaees B Compiled SCPI Software Installation C Compiled SCPI File Structure C SCPL Directori eSmanera ccs at cea Mana haaetes aan T Mara eda Other Directories caksiies soit cdleiasideivaedsiesvasacssevesgssaveresaeeesiatavergontee Structure for C SCPI on LynxOS 0 0 eee cseeeenee
48. ECL vm E1411B R ER void service INST_PARAM id E1411B R T_STARTUP OPEN vm vxi 24 T_ONSRQ vm service Chapter 5 97 Compiled SCPI Command Reference INST_OPEN INST_OPEN The instrument open command opens the I O channel of communication to the instrument specified by the id parameter REGISTER configured instruments are initialized and set to their power on state Syntax INST_OPEN id dev_addr Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_OPEN vm vxi 24 opens I O channel to E1411B dev_addr The SICL address for the instrument This address can be a quoted string or a pointer to a char array With a pointer to a char array you can assign card addresses at run time If a VXI instrument is used the vxi xx quoted string should be used with xx being the logical address of the instrument Multiple cards can be configured as a switchbox or scanning voltmeter To specify multiple cards enclose the card addresses in parentheses and separate with commas For example
49. Online Documentation Online Documentation One of the learning products C SCPI provides is online documentation We provide this online documentation in a form similar to UNIX manual pages By using the man command you can get information on C SCPI commands This appendix describes the C SCPI documentation and how to use it How To Use Manual Pages To use manual pages you type the man command followed by a C SCPI command or an HP register based instrument model number man name where name is either a C SCPI Macro command C SCPI function call or an HP register based instrument model number The following are examples of valid manual page commands man cscpipp man INST _DECL man cscpi_exe man cscpi_drivers man E1411B Whatis a A manual page is online documentation that is similar to the manual pages Manual P age provided in the UNIX environment Manual pages are provided for the following e C SCPI Macro Commands e C SCPI Function Calls e C SCPI Preprocessor Command e Each Supported HP VXI Register Based Instrument 132 AppendixA What Information is Provided in the Manual Pages C SCPI Macro Commands C SCPI Function Calls HP Register Based Instruments Online Documentation The C SCPI manual pages provide a general description of C SCPI commands and calls A quick reference for the supported HP register based instruments is also provided For additional information on these commands
50. Process C SCPI commands are preprocessed and translated into ANSI C function calls Figure 2 3 displays a sample of the ANSI C source code sourcel cs with C SCPI commands and the translation of the C SCPI commands Ssourcel c into ANSI C function calls after running the preprocessor The resulting ANSI C file contains code generated by the C SCPI preprocessor and is not intended to be modified by the user However line mapping information in the resulting ANSI C file will cause the C compiler to reference the original source file e g sourcel cs for any errors or warnings that you may receive 20 Chapter 2 Using Compiled SCPI C SCPI Source Code Preprocessor Translated Source Code INST_DECL vm E1411B REGISTER INST vm name E1411B mode REGISTER T STARTUP os_init STARTUP _OPEN vm vxi 24 extern vm_header_fn vm os_open vxi 24 vm_header_fn END vm CONF VOLT DC Sf numbl1 struct short subl char sub_pad 2 short pl_type char pl_type_pad 2 long p1 2 short p2_type char p2_type_pad 2 long p2 2 short p3_type char p3_type_pad 2 long p3 1 in_ line 30 sourcel cs in_ sub1 0 ine 30 sourcel cs in_ pl_type 0 PSL_FLOAT32 in_pl gt num numb1 ine 30 sourcel cs HPSL_FLOAT32 pl gt suffix 0 ine 30 sourcel cs in_ p2_type 1 ine 30 sourcel cs in_ p3_type
51. RE iintron See the HP SICL documentation for additional information on these commands If you are in the overlapped mode you can use OPC after the SCPI command to ensure the command has finished execution The following example uses OPC to ensure SCPI commands are done int result INS INS INS INS INS INS vm CONF VOLT gt DC Ta2d MAX sour SOUR VOLT1 2 7000 D sw ROUT CLOS 101 ERY sw OPC Sd amp result ERY sour OPC d amp result Q ERY vm OPC Sd amp result printf This is a test send s n text Notice that the write to terminal is after all of the OPC commands 44 Chapter 2 Determining the Order of your Overlapping Commands Note Using Compiled SCPI Overlapped Mode Programming for Efficiency Once you have decided to use the overlapped mode you can make your program more efficient by doing the following Change the order of the SCPI commands to increase your system throughput Use OPC commands to ensure commands have completed Each of these items is discussed in the subsections following To obtain optimum throughput you must write your program so that commands are executed in a particular order Use the following procedure to tune your program to get the best throughput 1 Determine if the command is overl
52. S numbl amp result If acomma is present in the format specifier the c_expr is a pointer to an array of floats instead of a numeric expression The comma operator is immediately followed by a number indicating the size of the array The comma can be useful when you have a list of channels to query For example float list 5 101 102 103 104 105 INST_QUERY sw CLOSE 5f 5d list amp result NOTE C SCPI requires that the comma operator s corresponding array contain the complete channel list In the C SCPI command above for example you cannot add another comma operator to specify more channels to query s The s format indicates that a string expression without quotations is used in c_expr For example char count 5 MAX INST_QUERY vm SAMP COUNT s Sd count amp result SS The s format indicates a string expression with quotations is used for c_expr See INST_SEND for example Sx The r format indicates an expression is used for c_expr See INST_SEND for example lt width gt The b format indicates that an array is used for c_expr lt width gt is size b either a number or an asterisk The number indicates the number of elements to be sent and the indicates that the number is taken from the next parameter for example 31024b or b See INST_SEND for an example size determines the size of each element in the array size
53. SCPI instrument syntax errors are reported when the C SCPI preprocessor runs Instrument run time errors however are not reported which can result in incorrect program data You can write a cscpi_error routine and link it into your C program This error routine would then be called every time an instrument run time error is put into the instrument s error queue If you do not use cscpi_error C SCPI provides adummy routine that does nothing Using cscpi_error allows you to write your own error routine to handle run time errors Several advantages of using the cscpi_error routine include the following You assure data is correct by guaranteeing no errors are in the instrument s error queue You avoid continually checking the instrument s error queue for run time errors cscpi_error is only called for REGISTER configuration types Chapter 4 81 VXI Instrument Run time Errors Troubleshooting Compiled SCPI A VXI instrument run time error is an error that occurs at run time and is put into the instrument s error queue Examples of run time errors include out of range errors and triggering too fast errors The following program segment causes a VXI instrument run time error This program segment sends a SCPI command to the HP E1411B Multimeter that is out of range include lt stdio h gt include lt cscpi h gt INST_D main ECL vm E1411B R flo
54. SCPI Preprocessor Errors Error Message Possible Cause duplicate device The device has already been defined in an INST_DECL INST_EXTERN or INST_PARAM unknown REGISTER driver C SCPI does not recognize the driver parameter for a REGISTER configuration in the INST_DECL INST_EXTERN or INST_PARAM command The driver may not be installed on your system or you may be typing it in wrong expected REGISTER or MESSAGE The type parameter must specify the type of configuration REGISTER or MESSAGE undeclared identifier The id that is being used was not declared in INST_DECL INST_EXTERN or INST_PARAM SCPI error lt errornumber gt lt error string gt SCPI syntax error error number is the instrument error number and error string is the instrument error text unknown driver The instrument used as the driver parameter when running the C SCPI preprocessor with i option is not recognized use INST_QUERY for commands The cmd_string parameter contains a SCPI command that has a question mark You must use the INST_QUERY command for SCPI query commands 146 Appendix E Error Messages Table E 1 C SCPI Preprocessor Errors Error Message Possible Cause expected response response format and pointer When using the INST_QUERY command you are missing the readfmt and or c_addr parameters expected response pointe
55. SEND assigns variable sends to E1411B vm E1411B REGISTE RST R vm cmd_string The string constant containing the SCPI command s See the instrument s VXI user s manual for information on the SCPI commands or see Appendix A Online Documentation for more information For example INST_SEND TERS TIB vm where RST is the cmd_string Any SCPI parameter in the string can be expressed with a format specifier If a format specifier is used each c_expr parameter that follows contains the corresponding C expression This is similar to the format specifiers inthe C printf function The following format specifiers are available for REGISTER configurations sda amp S Sa Sf Sr Ss Sb Each of these format specifiers is discussed on the following pages cmd_string Format Specifiers NOTE The format specifier must be the same type that the instrument expects If for example the instrument expects a float number you must use the f format specifier See the instrument s user s manual for information on what the SCPI command expects NOTE For MESSAGE configurations C SCPI uses the SICL iprintf function See the SICL documentation for additional information on the format specifiers for MESSAGE configurations 110 Chapter 5 Compiled SCPI Command Reference INST_SEND cmd_string Format
56. Sales and Service Office or see Appendix A Online Documentation for more information type The parameter that defines the configuration type The configuration type can be one of the following keywords MESSAGE for HP IB or VXI message based configurations REGISTER for register based configurations If you have a register based card configured over HP IB the configuration type is MESSAGE Comments e INST_DECL INST_EXTERN or INST_PARAM is required to declare the id parameter This declaration must be done before any use of the id parameter e See also INST_DECL and INST_EXTERN 100 Chapter 5 Compiled SCPI Command Reference INST_PARAM Example This example shows the INST_PARAM command used to pass the instrument declaration to the setup function setup INST_PARAM id E1411B R INST_SEND id RST ECL vm E1411B R TARTUP PEN vm vxi 24 Chapter 5 101 Compiled SCPI Command Reference INST_QUERY INST_QUERY The instrument query command sends the SCPI command s in the cmd_string parameter to the instrument defined by the id parameter This command also stores the result s from the query command in the address es specified by the c_addr parameter Syntax INST_QUERY id cmd_string
57. See Trapping Errors with cscpi_error in Chapter 4 for more information on the cscpi_error routine 50 Chapter 3 Programming with Compiled SCPI Programming with a Scanning Multimeter This programming example shows how you can use C SCPI macro commands to set up a measurement for a scanning voltmeter See Chapter 5 for more information on these commands Equipment Needed Embedded VXI Controller HP VXI Mainframe HP E1326B or HP E1411B Multimeter HP E1345A Relay Multiplexer Program Description This program uses C SCPI commands to set up a measurement for the Multimeter and the Relay Multiplexer to make a scanning measurement Program Listing examplel cs This programming example uses the C SCPI commands to make a measurement for a scanning voltmeter include lt stdio h gt include lt math h gt include lt cscpi h gt Needed for Preprocessor commands int testl void function prototype for testl INST_DECL vm E1411 R F declare instrument variable main int fail INST_STARTUP initialize instrument 2 operating system X EN vm vxi 24 25 open scanning meter using 1411 logical address 24 and scanner logical address 25 Continued on Next Page Chapter 3 51 Programming with Compiled SCPI printf open vm failed exit 1 fail testl if printf TEST FAILI else printf TEST P
58. TARTUP in the program before INST_OPEN 76 Chapter 4 Note Troubleshooting Compiled SCPI source2 cs set voltmeter to measure DC volts query for the results and print the results lude lt stdio h gt lude lt stdlib h gt lude lt cscpi h gt incl incl incl INS ECL vm E1411B REGIST numb1 2 0 vm_dc STARTUP _ OPEN vm Vxi 24 vm 0 Error Message open failed on vm cscpi open error number 5 Resolution This particular cscpi_open_error is error number 5 This error is reported because the instrument card does not exist at the address stated in the INST_OPEN command The program resolution is as follows main INST_STARTUP INST_OPEN vm Vxi 24 Once you have resolved a run time error you MUST re run the C SCPI preprocessor and re compile and link your code Otherwise you will be using the same code you were before Chapter 4 77 Troubleshooting Compiled SCPI Program Description numb1 2 0 loat vm_dc INST_STARTUP INST_OPEN vm VXI 32 if vm 0 printf open failed on vm n printf cscpi open error number cscpi_open_error exit 1 Other Causes Additionally there are other reasons INST_OPEN may fail with an error number 5 or error number 6 These are as follows SICL is not properly setup on the system where you are executing your
59. With this function the SCPI commands are parsed and executed at run time Syntax cscpi_exe id cmd_string cmd_length result result_length Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable cscpi_exe vm command strlen command result sizeof result sends to E1411B cmd_string The string variable containing the SCPI commands See the instrument s VXI User s Manual for information on the SCPI commands or see the instrument s C SCPI online documentation cmd_length The length of the cmd_string parameter If you are using this interactively you can use the C string length function strlen to get this length result The address location where the results of an instrument query are to be stored The address location must be a pointer of type char result_length The maximum length of the returned string If you are using this call interactively you can use the C size of function sizeof to get this length Comments e This function is only interactive if you write it into your program to prompt the user for SCPI c
60. _EXTERN 94 95 initialization 19 open command 98 99 parameter command 100 101 programming commands 19 query command 102 107 read status byte command 108 109 run time errors 82 119 send command 110 115 service request command 96 97 startup command 116 trigger command 117 Interactive Functions 32 35 62 63 advantages 32 debugging 32 error checking 32 programming with 34 35 62 63 using 32 33 Interrupts 43 L l Option 23 Learning About Compiled SCPI 11 14 Library 24 cscpi 24 m math 25 sicl 24 Linking cscpi library 23 errors resolving 69 73 g option 7 l option 7 23 o option 7 23 programs 7 source code 22 24 LynxOS File Structure 141 Index 5 M Macro Commands 87 117 133 INST_CLEAR 88 89 INST_CLOSE 90 91 INST_DECL 92 93 INST_EXTERN 94 95 INST_ONSRQ 96 97 INST_OPEN 98 99 INST_PARAM 100 101 INST_QUERY 102 107 INST_READSTB 108 109 INST_SEND 110 115 INST_STARTUP 116 INST_TRIGGER 117 Make Command 25 26 Makefiles 25 26 man Command 10 132 135 Manual Pages 132 135 appearance 134 135 C SCPI function calls 133 C SCPI macro commands 133 cscpi_drivers 133 how to use 132 135 register based instruments 133 MESSAGE Configuration INST_DECL 92 93 INST_EXTERN 94 95 INST_PARAM 100 101 mthreads Option 7 22 Multimeter programming with 51 52 N Non Overlapping Command 40 O o Option 23 Online Documentation 132 135 Online Help 132 1
61. ain int mode 1 cscpi_overlap mode Chapter 5 127 Compiled SCPI Command Reference Compiled SCPI Quick Reference Compiled SCPI Quick Reference Command Syntax Command Description INST_CLEAR id Sends an IEEE 488 2 equivalent device clear to the instrument specified by the id parameter INST_CLOSE id Closes the I O channel of communication with a device and releases memory used by the instrument driver INST_DECL id driver type Creates a variable declaration for the instrument specified by the driver parameter INST_EXTERN id driver type Creates an external variable for the instrument specified by the driver parameter INST_ONSROQ id c_function Installs the function specified by the c_function parameter as a handler to be called when the instrument specified by id asserts a service request INST_OPEN id dev_addr Opens the I O channel of communication with a device to the instrument specified by the id parameter INST_PARAM id driver type Defines an I O channel that will be passed to functions INST_QUERY id cmd_string Executes the SCPI command in the cmd_string parameter readfmt c_expr addressed to the instrument specified by the id parameter The c_addr c_addr query results are stored in the c_addr address INST_READSTB id c_addr Places the results of a serial poll from the
62. al screen The program continues until the user enters a lt Ctrl D gt which indicates the end of the file E1411B R INST_STARTUP INST_OPEN vm vxi 24 printf Enter SCPI Commands for E1411B Enter Ctrl D to quit n cscpi_exe_fildes vm 0 1 printf Done n Chapter 5 123 Syntax Parameters Comments Compiled SCPI Command Reference cscpi_exe_stream cscpi_exe_stream The C SCPI execute stream function allows you to specify a file or pipe that contains SCPI commands to be used as input The commands are executed and the results are stored in the file or pipe specified for output This function only works with REGISTER configurations With this function the SCPI commands are parsed and executed at run time cscpi_exe_stream id fin fout Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable cscpi_exe_stream vm stdin stdout sends to E1411B fin A FILE that contains SCPI commands to be executed The stream must contain ONLY SCPI commands for the REGISTER configured instrument specified in the id para
63. apping or non overlapping See Appendix A Online Documentation for the specific instrument 2 Determine which overlapping commands take the most time See the System Characteristics section of the HP 75000 Family of VXI Products catalog for a list of card execution times 3 Program the overlapping commands that take the most time first You will only gain throughput by overlapping commands to different instruments Suppose you have three commands for three different instruments and one is non overlapping and the other two are overlapping Send the overlapping command that takes the most time first Then send the other overlapping command and finally the non overlapping command Chapter 2 45 Using the OPC Commands Note Using Compiled SCPI Overlapped Mode In order to guarantee that commands have finished before you try to make a measurement use the operation complete query command OPC By using this command you can avoid incorrect data The following program segment is an example of using OPC int result INS END swl CLOSE 101 INS UERY swl OPC Sd amp result The WAI command takes slightly less time than the OPC command However WAI does not have the desired effect on MESSAGE instruments Therefore OPC is recommended for portability 46 Chapter 2 Programming with Compiled SCPI Programming with Compiled SCPI This chapter pro
64. at answer INST_STARTUP INS _OP INS E INS E EN D ND INS printf U ERY vm vxi 24 vm FUNC VOLT AC vm VOLT RANGE 400 vm READ Sf amp answer answer f n answer The program will run and provide an answer A run time error however was generated and put into the instrument s error queue You can add a SYST 7 ERR command to check each instrument The recommended method however is to use the cscpi_error routine to trap instrument run time errors as they occur 82 Chapter 4 Using cscpi_error Troubleshooting Compiled SCPI To use cscpi_error you must place a cscpi_error routine in your C program or in a separate file and link it in This routine is passed the SICL instrument id and the error number The following cscpi_error routine can be found in the usr hp75000 demos cscpi directory You can use this error routine edit this routine or you can write your own cscpi_error c This routine provides the SCPI error routine for run time errors Errors in the instrument s error queue are reported include lt cscpi h gt void cscpi_error INST sicl_inst int error_number char string 20 SYST ERR char result 255 cscpi_exe sicl_inst string strlen string result sizeof result printf exit 1 ERROR s result A The cscpi_error routine pro
65. b h gt header files and the C SCPI include lt cscpi h gt header file INST_DECL vm E1411B R global declaration of E1411B instrument register mod x void main float vm_dc float numb1 2 0 INST_STARTUP initialize instrument operating system INST_OPEN vm Vvxi 24 open voltmeter at Logical Address 24 if vm 0 check to see if open failed printf open failed on vm n printf cscpi open error number d n cscpi_open_error exit 1 INST_S END vm CONF VOLT DC numb1 configure for DC volt INST_QUERY vm READ amp vm_dc query for DC volt reading printf DC Voltage is f n vm_dc print the voltage RN exit 0 18 Chapter 2 Using Compiled SCPI Defining the C SCPI Commands Using C SCPI commands in your C program allows you to program at a high level instead of performing register reads and writes Refer to the Compiled SCPI Command Reference section later in this guide for a complete list and description of the C SCPI commands The following list describes the C SCPI commands used in the sourcel cs program e Header File provides function prototype and variable typing information that will be used by C SCPI commands include lt cscpi h gt e Instrument Declaration makes your instrument declaration using the INST_DECL comma
66. calls and HP register based instruments see the appropriate user s manual The C SCPI manual pages for C SCPI macro commands provide the documentation needed to use the C SCPI macro command The command syntax parameter description and an example programming segment are all provided The C SCPI manual pages for C SCPI functions provide the documentation needed to use the functions The parameter descriptions and an example programming segment are provided Each supported register based instrument has a C SCPI manual page that provides the SCPI command quick reference commands not supported in C SCPI commands changed in C SCPI query command response types a list of overlapping commands and restrictions on the INST_ONSROQ command There is also a C SCPI manual page called cscpi_drivers that provides a list of all instrument drivers available for C SCPI This manual page also lists what register based instruments are supported for each C SCPI driver You can use the cscpipp command to find out what drivers are installed on your system Appendix A 133 Online Documentation What Does a If forexample you need information on the HP E1326B Multimeter type the Manual Page Look following at the user prompt Like man E1326B The manual page for the HP E1326B Multimeter is similar to the following E1326B SCPI Command Quick Reference ESCRIPTION The following is a SCPI command quick reference for the HP E1326
67. cifier See the instrument user s manual for information on what the SCPI command expects NOTE For MESSAGE configurations C SCPI uses the SICL iprintf function See the SICL documentation for additional information on the format specifiers for MESSAGE configurations sd The d format indicates that an int is used as the numeric expression for the c_expr parameter For example int numbl INST_QUERY If acomma is present in the format specifier the c_expr is a pointer to an array of integers instead of a numeric expression The comma operator is immediately followed by a number indicating the size of the array The comma can be useful when you have a list of channels to query For example int list 5 NOTE C SCPI requires that the comma operator s corresponding array contain the complete channel list In the C SCPI command above for example you cannot add another comma operator to specify more vm ME AS rR ES d S numbl1 amp result 101 INST_QUERY sw CLOSI channels to query E 102 103 104 105 5d 5d list amp result Chapter 5 103 Compiled SCPI Command Reference INST_QUERY cmd_string Sf The format indicates that a float is used as the numeric expression for Format the c_expr parameter For example Specifiers continued float numbl INST_QUERY vm MEAS RES S
68. d 9 10 Internal SICL error has occurred Contact your local Support organization or 11 12 or 13 System encountered a resource problem Contact your local Support organization 14 Instrument driver cannot provide the required This occurs when the instrument driver is not information compatible with the version of C SCPI that is installed on your system 148 AppendixE Other Documentation Other Documentation The C SCPI manual set in itself does not provide you with all the information needed to successfully use this product The following list might help you find additional information HP Pentium Controller Learning Products e Lynx Real Time Operating System Learning Products e HP VXI Instrument Manuals 150 Appendix F Index A Accessing C SCPI Online Documentation 10 Advantages Compiled SCPI 12 cscpi_error routine 81 interactive functions 32 overlapped mode 36 ANSI C 6 11 B Block Data storing 27 28 59 61 C c Option 7 22 C Program getstrt1 cs 9 Clear Instrument Command 88 89 Close Instrument Command 90 91 Comma Operator INST_QUERY 103 INST_SEND 111 Command Reference 86 129 Commands OPC 44 46 WAT 46 c option 7 22 cscpi_datafile 28 cscpi_error 50 81 83 119 cscpi_exe 32 62 63 120 121 cscpi_exe_fildes 33 122 123 cscpi_exe_stream 33 124 125 cscpi_get_overlap 40 126 cscpi_overlap 40 42 127 cscpipp 10 133
69. e a OPC command to ensure the commands are completed Sequential Programming Overlapping Programming Configure voltmeter Set up source Set up source Close switch Wait for command to complete Query operation complete Close switch T Query operation complete I Query operation complete M Wait for command to complete Measure and return voltage Configure voltmeter Wait for command to complete Measure and return voltage Figure 2 6 Time for Sequential and Overlapped Programs Chapter 2 39 Using Compiled SCPI Overlapped Mode Overlapped Command An overlapped command is a command that allows other commands to be executed at the same time Some commands can be overlapped and some can not Some commands will not allow any other command to be executed after the command has started Therefore we have two types of commands e ANON OVERLAPPING command is a command that does not allow any other command to be executed after the command has begun The non overlapping command must complete execution before the next command can start An OVERLAPPING command is a command that allows other commands overlapping or non overlapping to other instruments to be executed at the same time An overlapping command continues execution when an interrupt from the hardware card is delivered to the test program Overlapping commands ONLY overlap when the
70. e applicable FAR or DFARS clause or the HP standard software agreement for the product involved Copyright 1997 Hewlett Packard Company All rights reserved This document contains information which is protected by copyright All rights are reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under the copyright laws Intel 486 is a U S trademark of Intel Corporation Pentium is a U S registered trademark of Intel Corporation UNIX is a registered trademark in the U S and other countries licensed exclusively through X Open Company Limited Printing History Edition 1 August 1997 Contents 1 Getting Started with Compiled SCPI Conventions USed ii ctecciteitessctucscoteceet ibeeeustadeseedtivectetituecdabtescvtbtespteleaess 2 Verifying your Compiled SCPI System 0 ce eeeeeeeeseeeseeensecsseceseeeeeenes 3 Preparation Check List ccsce cigeees beck eee oi an eee i s 3 Reviewing System Component cee eecesseeseceseceeeeeseeeseeeaeceseeneeeees 3 Verify System Setup setae fei iii iit nevi eet iat cee 4 Running your First Compiled SCPI Program ce cesceseceeeeeseeeeeeeees 6 Using the Getting Started Tutorial oo eee ceeceeeeeseeeeeeseeeeaeeenees 6 Review the C SCPI Process eceeceessceseeeseecseceseeceseeseeeseeeseeeaaecseenes 8 Reviewing getstrt cs Program csseessecssecsseceeceeeeeseceseeeeeeeeeeenaes 9 Accessing C SCPI
71. e of using the interactive functions is that error checking and parsing of SCPI commands is not done until run time instead of checked when the C SCPI preprocessor runs This in turn slows down the program execution speed Using Interactive Functions There are three interactive functions available with C SCPI The cscpi_exe function uses a string variable for input to the function The results are stored in the address specified With this function you have to specify the length of the SCPI command string and the size of the location used to store the results The following illustrates the function call instrument id size of result length of SCPI command cscpi_exe vm command strlen command result sizeof result string for SCPI command location to store result 32 Chapter 2 Using Compiled SCPI Interactive Functions The cscpi_exe_st ream function allows you to use streams as the file input and output The following illustrates the function call stream used for input cscpi_exe_stream vm fin fout l stream used for results The cscpi_exe_fildes function uses a file descriptor as file input and output The following illustrates the function call descriptor used for input cscpi_exe_fildes vm in out descriptor used for results See Chapter 5 Compiled SCPI Command Reference for more information on the C SCPI interactive functions Chapter 2 33 Equipment Needed Prog
72. ecutable Code creating 8 Executing GDB 80 External file programming with 53 55 triggering with embedded computer 64 variable reference 94 95 F f Option 27 28 59 61 File Descriptors 33 122 File Structure 140 141 Format Specifiers 103 105 111 113 a 105 113 b 104 113 d 103 111 f 104 111 r 104 112 S 104 112 s 104 112 F continued Function Calls 118 127 129 133 cscpi_error 119 cscpi_exe 32 62 63 120 121 cscpi_exe_fildes 33 122 123 cscpi_exe_stream 33 124 125 cscpi_get_overlap 40 126 cscpi_overlap 40 42 127 G g Option 7 22 GDB commands 79 executing 80 software tool 79 80 getstrtl cs Example Program 9 Getting Started with Compiled SCPI 2 14 Compiled SCPI 6 GNU Debugger 79 80 Group Execute Trigger 117 H Header File 19 Help error messages 146 148 online help 132 135 I I Option 7 22 i Option 29 31 lintroff Command 44 lintron Command 44 INST_CLEAR Command 88 89 INST_CLOSE Command 90 91 INST_DECL Command 92 93 INST_EXTERN Command 53 54 94 95 INST_ONSRQ Command 96 97 INST_OPEN Command 98 99 INST_PARAM Command 56 100 101 INST_QUERY Command 102 107 INST_READSTB Command 108 109 INST_SEND Command 28 110 115 INST_STARTUP Command 116 INST_TRIGGER Command 117 Installing Software 138 Instrument clear command 88 89 close command 90 91 declaration 19 INST_DECL 92 93 external INST
73. ed SCPI Command Reference cscpi_error cscpi_error The C SCPI error function provides error trapping for instrument run time errors Every time a run time error is put into an instrument s error queue a dummy cscpi_error function is called However if you write your own cscpi_error function and link it into your program your function will be called instead We have provided an example error routine you can use in your programs Syntax cscpi_error sicl_inst error_number Example The example cscpi_error routine provided is called when a run time error is put into an instrument s error queue This routine prints the instrument s error number and message If you use this error routine you must compile and link it into your main program cscpi_error c This routine provides the SCPI error routine for run time errors Errors in the instrument s error queue are reported include lt cscpi h gt void cscpi_error INST sicl_inst int error_number char string 20 SYST ERR char result 255 cscpi_exe sicl_inst string strlen string result sizeof result printf ERROR s result exit 1 See Chapter 4 Troubleshooting Compiled SCPI for more information on the cscpi_error routine Chapter 5 119 Compiled SCPI Command Reference cscpi_exe cscpi_exe The Compiled SCPI execute function allows you to use an interactive mode of operation with REGISTER configurations only
74. ed by the instrument driver INST_CLOSE id Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_CLOSE vm closes E1411B I O channel 90 An INST_OPEN must be executed earlier in the program to open the I O channel of communication and initialize the instrument driver If you do not use an INST_CLOSE command the I O channel will automatically be closed when the program terminates This is done by the underlying SICL I O Library Typical reasons for using the INST_CLOSE command include the following To open another I O channel of communication for the same instrument To use an instrument in a different configuration For example you want to change a switch card configured as part of a scanning voltmeter to a switchbox configuration e For MESSAGE configurations C SCPI uses the SICL iclose id function See the SICL documentation for more information e See also INST_OPEN Chapter 5 Compiled SCPI Command Reference INST_CLOSE Example This example opens an I O channel of communication for a voltmeter and
75. er is taken from the next parameter for example 1024b or b For example char data 1024 INST_SEND dig SOUR DIG TRAC DATA block 1024b data where 1024 bytes of the array called data is used You can also use an int or float array since C SCPI casts it to a char array size determines the size of each element in the array size can be one of the following pointer to an array of char 8 bits pointer to an array of long int 32 bit words pointer to an array of short 16 bit words pointer to an array of float 32 bit floating point numbers pointer to an array of double 64 bit floating point numbers The a format indicates that a binary FILE is used for c_expr lt width gt is either a number or an asterisk The number indicates the number of elements to be sent and the indicates that the number is taken from the next parameter for example 31024a or a For example int numb 1024 INST_SEND dig SOUR DIG TRAC DATA block a numb datafile where the first 1024 bytes of the file are sent to the dig size determines the size of each element in the array size can be one of the following binary file containing an array of char 8 bits binary file containing an array of int 32 bit words binary file containing an array of short 16 bit words binary file containing an array of float 32 bit floating point binary file containing an array of double 64 bit floating poi
76. expected i alil fail 1 return fail Expected Sf Af AY ERN C_SCPI command Needed for Preprocessor Ai declare external instrument variable xy a simple test function wf number of points 7 defin 130 5 30 xpected points Ds Oxo O09 LeOyp 2257 query for results and put in an array 100 109 SE a 01 measured f n Continued on Next Page 54 Chapter 3 Programming with Compiled SCPI example2a cs This programming example uses th xtern ANSI C command to execute test1 listed on the previous page include lt stdio h gt include lt math h gt include lt cscpi h gt Needed for Preprocessor commands INST_DECL vm E1411 R declare instrument variable extern int testl declare function from other file main int fail INST_STARTUP initialize instrument os cai OPEN vm vxi 24 25 open scanning meter using 1411 logical address 24 and scanner logical address 25 if vm printf open vm failed error number d n cscpi_open_error j exit 1 fail test1 run test using test1 external function if fail check to see if test passed or failed printf TEST FAILI else printf TEST PASSED n exit 0 Chapter 3 5
77. file to convert C SCPI programs cs files into C programs c files A TAB must precede cscpipp lt gt S c By putting these two lines at the beginning of your makefile you would not need the lines that Define name of source program in the previous example This approach uses suffix rules to accomplish the C SCPI preprocessing step The makefile in the examples directory uses this approach to compile C SCPI example code 26 Chapter 2 Preprocessor Command with f Option Using Compiled SCPI Preprocessor Options Preprocessor Options This section contains a short description of the C SCPI preprocessor command and its options The Compiled SCPI Preprocessor Command When using C SCPI the preprocessor command is as follows Options to the preprocessor command Source code ready to run through your C compiler cscpipp f block_file idriver file cs gt file c Your C program ready to run through the preprocessor The text in brackets are options discussed in the next section Storing Block Data in a Separate File The f Option When using SCPI commands that require block data to be sent to an instrument the f option can be used with the C SCPI preprocessor to store this block data in a file outside the C program This helps keep the size of the C program down the speed of the compilation up and allows for a smaller executable file This option is usually only needed if y
78. g your throughput with the overlapped mode 14 Chapter 1 Using Compiled SCPI Using Compiled SCPI This chapter discusses how to use C SCPI commands in your C programs and create executable code Using source code from the source1 cs program each step is presented and explained This chapter also describes preprocessor options interactive functions and the overlapped mode Overview of C SCPI Compiled SCPI C SCPI is a productivity tool designed to aid engineers in achieving high throughput with register based VXI instrumentation C SCPI takes a user s C program with special preprocessor commands and creates C source code The preprocessor commands contain high level standard SCPI commands as parameters Before compiling your C program the C SCPI commands are translated into C function calls The flowchart in Figure 2 1 describes the C SCPI process 16 Chapter 2 Using Compiled SCPI Write a C program with C SCPI commands example cs N include lt cscpi h gt INST_DECL vm E1411B REGISTER This is your C program with main C SCPI macro commands INST_STARTUP INST_OPEN vm vxi 24 INST_SEND vm RST ei You can use the make utility to 4 avoid multiple steps while Run Compiled SCPI Preprocessor compiling Preprocessor options are described in the cscpipp example cs gt example c Preprocessor Options section of this chapter The c is to comp
79. handler to be called when the instrument specified by id asserts a service request INST_ONSRQ id c_function Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_ONSRQ vm services calls service when E1411B asserts service request c_function The C function that is called when a service request is asserted from the instrument defined by the id parameter When writing your C function you must include the INST_PARAM command so that you can pass the instrument id See the example shown on the next page 96 To disable the service request set the c_function parameter to 0 It is good practice to disable service request when entering a service routine This avoids any confusion that would result by calling the service routine while already executing this routine If an SRQ function is called it should generally not send commands to an instrument if the main program is using the same instrument Also some register based instrument commands should not be executed from an SRQ function called from an interrupt routine See the instrument s C SCPI online d
80. he f option the data that is stored in the example dat file See the HP E1330B Digital I O User s Manual for more information on the SCPI command In order to read the block data when the program is executed the file containing the block data must be opened and assigned to the cscpi_datafile pointer Therefore in the example above the file called example dat is opened and assigned to the pointer cscpi_datafile 28 Chapter 2 Note Preprocessor Command with i Option Using Compiled SCPI Preprocessor Options C SCPI requires the name of the pointer to the data file to be cscpi_datafile The name of the file however is defined by the user Using SCPI Only Files The i Option The i option takes a file that contains only SCPI commands and converts it into a C function The C SCPI preprocessor treats each SCPI command in the file like an INST_SEND When using the C SCPI i option the following restrictions apply All SCPI commands must be for the same instrument SCPI query commands are NOT allowed Any text that is not a SCPI command is NOT allowed for example comments The C SCPI preprocessor command with the i option can be used as follows cscpipp i E1411B scpifile cs gt scpifile c Where i E1411B scpifile cs specifies that the file scpifile cs contains only SCPI commands for a multimeter Each command is treated as a C SCPI INST_SEND The resulting C program is called scpifile c To
81. helps alleviate upgrade and obsolescence problems since instruments understand the same commands regardless of manufacturer In the U S call HP Press at 800 333 0088 to order your Beginner s Guide to SCPI This product is intended for software developers with a working knowledge of the C programming language Advantages of Using Compiled SCPI Compiled SCPI allows you to achieve the high throughput of register based cards with the ease of high level programming The following lists the advantages of using C SCPI High throughput of register based VXI instruments Easy to understand SCPI commands Use of industry standards VXIbus and SCPI Supports register based message based and HP IB instruments Can use standard debugging tools C SCPI preprocessor has a small command set 12 Chapter 1 VXI Instruments Embedded VXI Controller More about Compiled SCPI and SICL Getting Started with Compiled SCPI Learning About Compiled SCPI Compiled SCPI System See the specific VXI Instrument manual for information on instrument operating instructions and configuration There is also online documentation provided that contains a quick reference of SCPI commands and detailed information about the card s operation with C SCPI See Appendix A later in this guide The embedded VXI controller is an HP Pentium computer based on the Intel 486 Pentium processor In this configuration it acts as a VXI slot 0 system co
82. her directory that also contain C SCPI files 1ib usr include usr man usr man cat1 usr man cat3 usr man cat5 The lib thread libcscpi 1ib libcscpi a file 140 common library files Libcscpi a is stored here common header files cscpi h is stored here manual pages common manual pages C SCPI commands man pages are stored here common manual pages C SCPI functions and library routines man pages are stored here common manual pages C SCPI instrument specific details man pages are stored here a file is symbolically linked to the Appendix C Compiled SCPI File Structure Structure for C SCPI on LynxOS Structure for C SCPI on LynxOS Diagram for C SCPI Directories usr hp7500 Appendix C 141 Compiled SCPI File Structure Structure for C SCPI on LynxOS Notes 142 Appendix C Threads and Compiled SCPI Threads and Compiled SCPI LynxOS supports a multi threaded processing model Lynx uses the POSIX thread facilities that are based on the preliminary draft of POSIX 1003 4a draft 4 See the LynxOS documentation for information on Lynx threads and using them Writing your Compiled SCPI Programs When you write your C SCPI C programs using multiple threads the following restrictions apply INST_STARTUP can only be called once in your program This C SCPI command is used to start the register based operating system and cannot be executed more than once INST_OPEN a
83. hile overlapped mode was ON additional interrupts can be generated if those commands have not completed yet Chapter 2 41 Determining if Overlapped Mode is ON or OFF Using Compiled SCPI Overlapped Mode The cscpi_get_overlap function returns an integer that tells if the overlapped mode is ON or OFF If a 1 is returned overlapped mode is ON A 0 indicates that overlapped mode is OFF The following program segment shows how you can store the current status of overlapped mode turn overlapped ON perform a function and then return overlapped mode to the same status it was before the function location to store old mode int old_mode int new_mode 1 store old mode and old_mode cscpi_get_overlap turn overlap mode ON cscpi_overlap new_mode cscpi_overlap old_mode put mode back to what it was before function The returned mode tells if overlapped mode is ON or OFF This mode is stored and the overlapped mode is turned ON Once the function is done overlapped mode is put back to whatever it was before the function began See Chapter 5 for more information on the cscpi_get_overlap call 42 Chapter 2 Using Compiled SCPI Overlapped Mode Controlling Overlapped Execution Most C SCPI instrument drivers use interrupts to perform their tasks When overlapped mode is on these interrupts may interrupt the execution of your test program The following example illustrates how interrupts could occur Configu
84. id c_dddr 0 00 ccc cece Page 108 INST_SEND id cmd_string c_expr 06 ccc cc eee ee Page 110 INST STARTUP e eine wet a a ite eae a a a a Page 116 ENSTATRIGGER O ck oats tose s D AEE area bebe Page 117 Compiled SCPI Functions cscpi_error sicl_inst error_number Page 119 cscpi_exe id cmd_string cmd_length result result_length Page 120 cscpi_exe_fildes id in OUt 0 0 0000 0 00000 Page 122 ecscpi_exe_stream id fin fout iter reat Page 124 cscpig t overlap C pice ign Sedan Se e e n Page 126 cscpi_overlap Mode areeni erate e eee ee Page 127 Compiled SCPI Quick Reference Page 128 86 Chapter 5 Compiled SCPI Command Reference Compiled SCPI Macro Commands The C SCPI macro commands are replaced by driver calls for REGISTE E configurations when the configurations and SICL commands for M ESSAG R C SCPI preprocessor runs Each C SCPI macro command syntax is described in the following form C SCPI Macro Command parameter1 parameter2 parameter3 etc Commands are listed at the top of the page Each command has a short description and the following information Command Syntax Parameters Comments Example Program Segment Chapter 5 87 Syntax Parameters Comments Compiled SCPI Command Reference INST_CLEAR INST_CLEAR The instrument clear command sends an IEEE 488 2 de
85. ile only Run your C w g is to generate debugging information mthread is to c g mthread n use threaded functions Link your code with t libraries cc mthreads o example Link in the cscpi and sicl libraries 2 arnie o lescpi eeh a Run the executable 4 This is your executable code y C example gt Figure 2 1 Flowchart of C SCPI Process Chapter 2 17 Using Compiled SCPI Creating Source Code This section describes a C source program with C SCPI commands As an experienced C programmer you are already familiar with using the C language Now you can add C SCPI commands to your program to achieve high throughput from your register based VXI instruments You can use the same syntax to operate your HP IB and message based devices also The discussion revolves around a short but reasonably typical C program named sourcel cs The sourcel cs program like all the examples in this guide is located in the directory usr hp75000 demos cscpi Once you have copied the sample program into your own directory you can treat it as you would any C source program The sourcel cs program is shown below for the discussion in this chapter The sourcel cs program uses C SCPI to send SCPI commands to set the voltmeter for DC Voltage and read the DC Voltage The voltage is printed using the printf function include lt stdio h gt include standard C runtime include lt stdli
86. iled SCPI e Processor pane User s test program with The HP C SCPI Preprocessor Precompiled code that embedded C SCPI macro that translates commands is ready to run through commands into driver and SICL calls your compiler linker The user s standard C code is not affected by the C SCPI preprocessor The user determines which ANSI C compiler to use and the code retains its portability Additionally standard debugging utilities can be used to debug programs Chapier 1 11 What Is VXI What Is SICL What Is SCPI Who Should Use Compiled SCPI Getting Started with Compiled SCPI Learning About Compiled SCPI VXIbus is an open architecture instrument interface for cardcage instrumentation It was created and is supported by a consortium of manufacturers Since VXIbus is an open standard you can have a multi vendor environment To find out more about VXIbus order your own Feeling Comfortable with VXI book with HP P N 5952 3080 HP Standard Instrument Control Library SICL provides a modular instrument communications library that works with a variety of computer architectures I O interfaces and operating systems It uses standard functions to communicate over a wide variety of interfaces See the HP SICL documentation for additional information Standard Commands for Programmable Instruments SCPI is an industry standard instrument control language that is supported by a consortium of manufacturers Using SCPI
87. ing first program 6 Run time commands 32 errors 74 78 82 119 148 S Scanning Multimeter programming with 51 52 SCPI Commands using 29 31 SCPI Description 12 Send Instrument Command 110 115 Sequential commands 38 39 programming 36 Service Request Command 96 97 SICL description 12 library 24 more about 13 Software Installation 138 Source Code compiling linking 22 24 creating 18 Start Instrument Command 116 Storing Block Data 27 28 59 61 Streams 33 124 125 Syntax Errors 66 System Configurations 48 T Threads and C SCPI 144 Throughput comparing two programs 38 39 Compiled SCPI 12 14 message based cards 12 14 order of commands 45 overlapped mode 37 39 register based cards 12 14 Time for overlapped programs 39 for sequential programs 39 Trapping Errors 50 81 83 Trigger Instrument Command 117 Triggering with HP Embedded Computer 64 Troubleshooting 66 83 Tutorial 6 U Usage Errors 67 68 Using OPC 44 46 Compiled SCPI 16 46 in interactive mode 62 63 C SCPI 16 46 in interactive mode 62 63 cscpi_error 83 GDB software 79 80 GNU debugger 79 80 interactive functions 32 33 libraries 24 makefiles 25 26 overlapped mode 40 42 SCPI only files 29 31 Index 7 Vv Verifying C SCPI system 3 5 system setup 4 5 VXI controller embedded 13 49 description 12 instrument run time errors 82 instruments 13 W WAI 46 Wa
88. instrument specified by the id parameter in the address location specified by the c_addr parameter INST_SEN c_expr D id cmd_string Executes the SCPI command in the cmd_string parameter addressed to the instrument specified by the id parameter INST_STARTUP Starts the register based operating system INST_TRI GGER id Sends an IEEE 488 2 equivalent group execute trigger to the register based instrument specified by the id parameter 128 Chapter 5 Compiled SCPI Command Reference Compiled SCPI Quick Reference C SCPI Calls C SCPI Call Description cscpi_error sicl_inst error_number Provides error trapping for instrument run time errors cscpi_exe id cmd_string cmd_length result result_length Executes the SCPI cmd_string parameter at run time The cmd_string parameter can be entered at run time cscpi_exe_fildes id in out Executes SCPI commands using file descriptors as input and output to the command cscpi_exe_stream id fin fout Executes SCPI commands using streams as input and output to the command cscpi_get_overlap Returns an integer value if overlapped mode is ON 1 or OFF 0 cscpi_overlap mode Turns overlapped mode ON 1 or OFF 0 Chapter 5 129 Compiled SCPI Command Reference Compiled SCPI Quick Reference Notes 130 Chapter 5
89. it for Complete WAD 46 Writing C SCPI Programs 144 Index 8
90. l of the SCPI commands are done before taking a measurement Sequeniial cscpi_overlap 0 Set up source _SEND sour SOUR VOLT1 2 7000 wait for command to complete Close switch END sw ROUT CLOS 101 wait for command to complete Configure voltmeter _ END vm CONF VOLT DC 7 27 MAX wait for command to complete Measure and p ERY vm READ f amp storage return voltage Overlapped cscpi_overlap 1 Configure voltmeter _p NST_SEND vm CONF VOLT DC 7 27 MAX Set up source __ _ __ gt END sour SOUR VOLT1 2 7000 Close switch I sw ROUT CLOS 101 o en operation ERY sw OPC sda amp result nDe ERY sour OPC Sd amp result j E vm OPC Sd amp result Measure and ERY vm READ f amp storage return voltage Figure 2 5 Programming Code Overlapped vs Non Overlapped 38 Chapter 2 Using Compiled SCPI Overlapped Mode While the program segments are listed in Figure 2 5 Figure 2 6 illustrates the time difference between the sequential and overlapped programs In the sequential program version with overlapped mode OFF each command will wait for completion before executing the next line With MESSAGE configurations however you must includ
91. mands for E1411B Enter Ctrl D to quit n cscpi_exe_stream vm stdin stdout printf Done n Chapter 5 125 Syntax Example Compiled SCPI Command Reference cscpi_get_overlap cscpi_get_overlap The Compiled SCPI get overlap function returns an integer value that tells if the overlapped mode is ON 1 or OFF 0 cscpi_get_overlap This example stores the current status of the overlapped mode turns overlapped ON performs a function and then returns overlapped mode to the status it had before main int old_mode int new_mode 1 old_mode cscpi_get_overlap cscpi_overlap new_mode cscpi_overlap old_mode 126 Chapter 5 Compiled SCPI Command Reference cscpi_overlap cscpi_ overlap The compiled SCPI overlap function turns the overlapped mode of operation ON or OFF Turning this mode ON allows overlapping commands to be executed in parallel with other commands Syntax cscpi_overlap mode Parameters Parameters Description mode Determines if overlapped is ON or OFF mode is an integer Any non zero value turns overlapped ON and 0 turns it OFF Comments e Before using the overlapped mode see Overlapped Mode in Chapter 2 for information on the possible side effects e Overlapped mode is set to O OFF by the C SCPI INST_STARTUP command Example This example shows how to turn the C SCPI overlapped mode ON m
92. ment trigger command sends an IEEE 488 2 equivalent group execute trigger to the instrument specified by the id parameter Syntax INST_TRIGGER id Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_TRIGGER vm Triggers E1411B Comments e For MESSAGE configurations C SCPI uses the SICL it rigger id function See the SICL for more information Example This example shows the instrument trigger command being used ECL vm E1411B R T_STARTUP OPEN vm vxi 24 ER vm Chapter 5 117 Compiled SCPI Command Reference INST_TRIGGER Compiled SCPI Functions The Compiled SCPI functions are provided as additional set of functionality Each function is described in the following form C SCPI Function parameter parameter2 parameter3 etc The C SCPI function is listed at the top of the page Each function has a short description and the following information Function Syntax Parameters Comments Example Program Segment 118 Chapter 5 Compil
93. meter stdin can be used to get input from the terminal keyboard fout A FILE where the results of the executed SCPI commands will be stored stdout or stderr can be used to display the results on the terminal display 124 Since stdin stdout and stderr can be used you can do terminal T O without having to open extra files ONLY SCPI commands for the instrument specified in the id parameter can be used in the input file The input and output may be piped or redirected to another controlling process Connecting st din and stdout to pipes allows you to have a separate process that is independent of SCPI or C SCPI See the Lynx manuals for more information on piping or redirecting to other processes Chapter 5 Compiled SCPI Command Reference cscpi_exe_stream e If fout is a pipe the c function setbuf fout NULL must be used to disable buffering If this function is not used you will not get an output until the stream buffer is full See the Lynx manuals for additional information Example Thisexampleuses the st dinand stdout files withthe cscpi_exe_stream function The user can enter the SCPI commands from the terminal keyboard and see the results on the terminal screen The program will continue to run until the user enters a lt Ctrl D gt which indicates the end of a file E1411B R INST_STARTUP INST_OPEN vm vxi 24 printf Enter SCPI Com
94. nd This declares vm for you as type INST INST_DECL may be a global or local declaration INST_DI ECL vm E1411 R EGIST ER e Instrument Initialization initializes your instruments using C SCPI commands INST_STARTUP starts the instrument register based operating system It must be executed before C SCPI commands except INST_DECL INST_OPEN initializes your instrument and instrument driver It must be executed after INST_STARTUP and before other instrument commands INST_STARTUP i INST_OPEN vm vxi 24 e Instrument Programming Commands send commands to your instruments and query for the results using standard SCPI commands with the most commonly used C SCPI commands INST_SEND and INST_QUERY INST_S INST_QUERY vm R Chapter 2 END vm CONF VOLT DC BAD SE amp vm_dc 3 numbl 19 Using Compiled SCPI Running the C SCPI Preprocessor This section provides a guide to running the C SCPI preprocessor Figure 2 2 displays the preprocessor process To run the C SCPI preprocessor type the following at the command prompt cscpipp sourcel cs gt sourcel c C Code ready for the compiler ECL vm B1411B gt to create an object file EGISTER T_STARTUP C SCPI _OPEN vm vxi 24 Preprocessor Language Tables Figure 2 2 C SCPI Preprocessor
95. nd INST_CLOSE must not be called from multiple threads at one time When these C SCPI commands are executed the address table is modified and you must not write to this table from multiple threads at the same time You must not access the same instrument from multiple threads at one time Most C SCPI commands access instruments Some of the commands are INST_SEND INST_QUERY INST_TRIGGER cscpi_exe etc See Chapter 5 for a complete list of C SCPI commands You can protect your program against simultaneous access to one instrument from multiple threads with the LynxOS mutex library functions See the LynxOS documentation for information on using these functions Compiling your Compiled SCPI Programs The HP SICL library uses threads during its normal execution For this reason all C SCPI programs are compiled with the multi threaded option to gcc If you use threads in your C SCPI C programs you do not need to do anything differently during the compile and link steps 144 Appendix D Error Messages Error Messages This appendix lists the possible errors you can receive while using the C SCPI preprocessor Compiled SCPI Preprocessor Errors The errors listed in the following table can be generated by the C SCPI preprocessor C SCPI checks for instrument syntax errors when the C SCPI preprocessor runs The parameter ranges however are not checked until run time which will generate a run time error Table E 1 C
96. ne terminator n or if the instrument expects one e Online documentation is provided The documentation contains a SCPI quick reference commands not supported commands changed the SCPI command query response types a list of overlapping commands and ONSRQ restrictions Online documentation is supplied for each supported card See Appendix A Online Documentation for additional information e See also INST_QUERY 114 Chapter5 Compiled SCPI Command Reference INST_SEND Example This example sends the select measurement function to the HP E1411B Multimeter The S format specifier indicates that t ype is declared as a quoted string INST _DECL vm E1411B R main char type 10 FRES INST_STARTUP INS PEN vm vxi 24 INST_SEND vm SENSE FUNCTION S type Chapter 5 115 Compiled SCPI Command Reference INST_STARTUP INST_STARTUP The instrument start up command starts the register based operating system Syntax INST_STARTUP Comments e This command must be executed before any other REGISTER configured commands Example This example shows a common place to use the instrument start up command INST_DECL vm E1411B R main INST_STARTUP EN vm vxi 24 EAR vm 116 Chapter 5 Compiled SCPI Command Reference INST_TRIGGER INST_TRIGGER The instru
97. ng example4 cs This program can be used with the f option so that the block data is stored in a separate file by the preprocessor 37 include lt stdio h gt include lt cscpi h gt define DIG_ADDR vxi 144 INST_DECL dig E1330B R A define instrument variable FILE cscpi_datafile must be used as pointer to file opened for block data main INST_STARTUP start operating system 7 INST_OPEN dig DIG_ADDR initialize digital I O card xtest to see if INST_OPEN worked 0 returned in failed if dig printf Open FAILED Error number d n cscpi_open_error exit 1 open data file for block data cscpi_datafile fopen example4 dat rb test to see if fopen worked if cscpi_datafile printf Open example4 dat failed n exit 1 Continued on Next Page 60 Chapter 3 Programming with Compiled SCPI call function with block data load_traces put your test here exit 0 function to load traces load_traces This function generates code to send data to an instrument When the C SCPI preprocessor is run the data is put in the file that cscpi_datafile is pointing to set up memory block to send data INST_SEND dig DIG TRACE DEF blockl 1000 INST_SEND dig DIG TRACE DEF block2 1000
98. ng at the command prompt man cscpi_drivers You can also use the cscpipp command to find out what drivers are installed on your system For additional information on accessing C SCPI online documentation refer to Appendix A C SCPI manual pages include the following topics e C SCPI Macro Commands e C SCPI Function Calls e C SCPI Preprocessor Command e Each Supported HP VXI Register Based Instrument 10 Chapter 1 Getting Started with Compiled SCPI Learning About Compiled SCPI Learning About Compiled SCPI Compiled SCPI C SCPD is a productivity tool designed to aid programmers in achieving high throughput of register based VXI instrumentation This is all done while using the easy to understand SCPI language C SCPI takes a user s C program with special preprocessor commands and creates C source code The user writes the test program in ANSI C language with the C SCPI preprocessor commands The preprocessor commands contain specific SCPI commands as arguments When the C SCPI preprocessor runs it traps all C SCPI commands and replaces them with actual driver calls If the instrument is message based or HP IB Hewlett Packard Interface Bus C SCPlI uses the appropriate HP SICL Standard Instrument Control Library function to perform the task The user then runs the output file through the ANSI C compiler and linker to create the executable code C SCPI macro command that sends a reset to the multimeter eee Comp
99. nt Chapter 5 113 Compiled SCPI Command Reference INST_SEND c_expr The expression that is used if a format specifier appears in the cmd_string parameter Any valid C expression can be used The preprocessor does not check to make sure it is the same type as the format specifier Comments e Multiple SCPI commands can be combined in the cmd_string parameter As with SCPI these commands are separated by semicolons For example RST SENS FUNC VOLT AC is a common command RST linked with a SCPI command SENS FUNC VOLT AC separated by a semicolon e The cmd_string parameter must be a quoted string The SCPI command cannot be a variable If you want to use a string variable use the cscpi_exe function call Since HP VXI instruments and the Controllers use different types of microprocessors the byte ordering is critical in the 3b and a blocks SICL takes care of the MESSAGE configurations For REGISTER configurations however you must know what data size 8 16 32 etc the instrument expects See the C SCPI online Documentation for the specific instrument and use the format specifiers to specify the size of the data type e For MESSAGE configurations C SCPI uses the SICL iprint f function See the SICL documentation for more information e When you send a SCPI command to a MESSAGE configuration you may have to include an end of li
100. ntroller and resource manager The main software items include the following e SICL includes both the software that allows the controller to act as a resource manager and the SICL I O library The resource manager runs automatically at start up and determines the system configuration SICL is an input output library that provides communication between the embedded VXI controller and the VXI and or HP IB instruments Lynx Real Time Operating System is the program that provides the system control and manages the system s resources HP Compiled SCPI is a programming tool that consists of C SCPI driver libraries and a preprocessor The C SCPI preprocessor transforms the C SCPI programming commands into driver and SICL calls Compiled SCPI uses HP SICL calls for communication between devices in your system C SCPI allows users to program with the SCPI language to perform instrument tasks Without C SCPI the programmer would have to either use SICL calls to write directly to the instrument s registers or use a command module to interpret the SCPI commands Writing to the instrument s registers can be very complex and time consuming and using a command module slows down the program execution speed since the SCPI commands are interpreted at run time instead of compile time as with C SCPI There may be times when you want to program with both C SCPI and SICL commands SICL calls are normally used when you have a register based instrument in your sys
101. ocumentation for information on when a register based instrument causes an SRQ function to be called from an interrupt routine See the SICL documentation for more information on message based devices Chapter 5 Compiled SCPI Command Reference INST_ONSRQ e The SICL iintron and iintroff functions can NOT be used for disabling and enabling the C SCPI ONSRQ interrupts in REGISTER configurations REGISTER configurations may call the c_function specified in the INST_ONSRQ macro command from within other INST functions MESSAGE configurations however use the SICL interrupts and can be enabled or disabled using these SICL functions e For MESSAGE configurations C SCPI uses the SICL ionsrq function See the SICL documentation for more information e When writing your C function to be called with a service request you must include the INST_PARAM command to pass the instrument id e If you use INST_ONSRQ while in the overlapped mode you can come across other problems where your controller may be doing other tasks rather than finishing up the instrument command See Overlapped Mode in Chapter 2 for additional information e The INST_ONSROQ command cannot be executed before an INST_OPEN command e See the SRE command in the VXI instrument User s Manual Example This example shows the call service if the HP E1411B Multimeter asserts a service request INST_D
102. ogram on page 9 2 Run the C SCPI Preprocessor Run the C SCPI preprocessor to translate your C SCPI commands into C function calls by typing the following at the command prompt cscpipp getstrtl cs gt getstrtl c 3 Compile your program Compile your program by typing the following at the command prompt gcc c g mthreads getstrtl c 6 Chapter 1 Getting Started with Compiled SCPI Running your First Compiled SCPI Program Comments The c option creates a file called getstrtl o The g option indicates to the compiler that the output should contain debug information this is optional The mthreads option indicates threaded functions are being used The I option causes the listed path to be searched for more include files 4 Link your program Link your program by typing the following at the command prompt gcc g mthreads o getstrtl getstrtl o lescpi lsicl Comments The g option indicates to the linker that the debugger is being used The mthreads option indicates threaded functions The o option creates an executable file called getstrt1 The 1 options link in the C SCPI and SICL libraries 5 Execute your program Execute your program by typing the following at the command prompt getstrtl The result of executing this program should be SIMILAR to the following The id of this module is HEWLETT PACKARD E1411B 0 E 05 02 Note To Com
103. ommands See Interactive Functions in Chapter 2 for a more detailed example of cscpi_exe e The char array returned for result includes a new line at the end of the array Therefore you do not have to include a new line if you print the results 120 Chapter 5 Compiled SCPI Command Reference cscpi_exe Example This example shows cscpi_exe being used in a loop prompting for input E1411B R main char result 255 char command 255 INST_STARTUP INST_OPEN vm vxi 24 for 77 printf Enter Command n gets command cscpi_exe vm command strlen command result sizeof result if result 0 0 printf The result of the s command is s command result F Chapter 5 121 Compiled SCPI Command Reference cscpi_exe_fildes cscpi_exe_fildes The C SCPI execute file descriptor function allows you to specify a file descriptor as an input file or pipe that contains SCPI commands to be executed The results of the executed SCPI commands are put into the file descriptor specified for output This function only works with REGISTER configurations With this function the SCPI commands are parsed and executed at run time Syntax cscpi_exe_fildes id in out Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL
104. on number Chapter 1 5 Note Getting Started with Compiled SCPI Running your First Compiled SCPI Program Running your First Compiled SCPI Program This section provides a guide to using HP Compiled SCPI C SCPI commands within your C program and to running the C SCPI preprocessor This chapter focuses on using C SCPI Commands and its preprocessor It does not focus on teaching you how to program using the GNU CC Compiler provided by Lynx Real Time Systems Inc A tutorial is provided to step you through the C SCPI process of creating executable code It uses a simple C program with C SCPI commands to get you up and running quickly This program does not attempt to do anything very ambitious Task oriented programs are provided in Chapter 3 Using the Getting Started Tutorial This section steps you through the process for creating C SCPI executable code 1 Copy the getstrtl cs program to your directory The program getstrt1 cs is located in the directory usr hp75000 demos cscpi Once you have copied the sample program into your own directory you can treat it as you would any C program Figure 2 1 lists getstrt1 cs in its entirety for your convenience and is displayed later in this chapter This example uses a Hewlett Packard multimeter HP E1411B instrument at logical address 24 Note if your multimeter is NOT at logical address 24 you must change the address in the C SCPI example program See Reviewing getstrtl cs Pr
105. open function The command opens a connection to the instrument without performing an initialization See the SICL documentation for more information e See also INST_CLOSE Example This example initializes the HP E1411B and HP 3457A Multimeters and checks for errors ECL vml E1411B R ECL vm2 3457A M INST_STARTUP INST_OPEN vml vxi 24 if vml 0 printf INST_OPEN failed C SCPI error sd n cscpi_open_error exit 1 INST_OPEN vm2 hpib 22 Chapter 5 99 Compiled SCPI Command Reference INST_PARAM INST_PARAM The instrument parameter command defines an I O channel to be passed to functions This command is used when the instrument is declared out of scope and you need to pass the instrument declaration into a function Syntax INST_PARAM id driver type Parameters Parameter Description id The user variable name for the instrument This is where you declare the variable for the instrument This variable name will be used by other C SCPI commands For example INST_PARAM vm E1411B REGISTER assigns vm to the E1411B driver The parameter that defines the HP driver This parameter is a quoted string for example E1411B is the driver name for the HP E1411B Multimeter See the HP 75000 Family of VXI Products catalog for a list of available drivers available from your nearest HP
106. or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable cscpi_exe_fildes vm 0 1 sends to E1411B in An integer as the file descriptor to determine the input file This file needs to contain SCPI commands to be executed The SCPI commands must be for the REGISTER configured instrument specified in the id parameter out An integer as the file descriptor to determine the output file The results from the executed SCPI commands are stored in this file Comments e Since stdin 0 stdout 1 and stderr 2 can be used you can do terminal I O without having to open extra files e ONLY SCPI commands for the instrument specified in the id parameter can be used in the input file e The input and output may be piped or redirected to other controlling processes Connecting stdin 0 and stdout 1 to pipes allows you to have a separate process that is independent of SCPI or C SCPI See the Lynx manuals for more information on piping or redirecting to other processes 122 Chapter5 Compiled SCPI Command Reference cscpi_exe_fildes Example This example uses the st din 0 and stdout 1 file descriptors with cscpi_exe_fildes The user can enter the SCPI commands from the terminal keyboard and the results are displayed on the termin
107. ou have a lot of block data The C SCPI preprocessor command with the f option can be used as follows cscpipp f example dat example cs gt example c Where f example dat example cs specifies that all block data in the program called example cs is to be stored in the file call example dat when the preprocessor runs The resulting C program is called example c See Chapter 3 Programming with Compiled SCPI for a more detailed example program using the f option Chapter 2 27 Example Program example cs Using Compiled SCPI Preprocessor Options The following program segment contains a SCPI command that sends block data to an instrument When the f option is used with the C SCPI preprocessor as shown in the previous section the data will be stored in the file specified in the command line Additionally in order to get the data when you run your program you must open the file that contains the block data and assign it to the cscpi_datafile pointer shown below E cscpi_datafile assign pointer for data retrieval assign cscpi_datafile pointer open file and assign to cscpi_datafile open file dat ae rp and assign cscpi_datafile fopen exampl Pi p g to pointer INST_SEND digio SOURCE DIGITAL TRACE DATA first_block 210ABCDEFGHIJ The INST_SEND command has a SCPI command that sends block data to the digio When the C SCPI preprocessor is run with t
108. pile and Link in one step refer to Compiling Linking your Code in Chapter 2 Also you can use a makefile to run the preprocessor compile and link your programs Refer to Using Makefiles in Chapter 2 for information on using a makefile Chapter 1 7 Getting Started with Compiled SCPI Running your First Compiled SCPI Program Review the C SCPI Process The following flowchart defines the C SCPI process to create executable code 1 Copy the getstrtl cs program or Write a C program with C SCPI commands getstrtl cs include lt cscpi h gt INST DECL vm E1411B R main INST_STARTUP INS PEN vm vxi 24 INST_SEND vm RST 2 Run the C SCPI Preprocessor cscpipp getstrtl cs gt getstrtl c 3 Run your C compiler gcc c g mthreads getstrtl c 4 Link your code with C SCPI and SICL libraries gcc g mthreads o getstrtl getstrtl o lescpi lsicl 5 Run the executable code getstrtl 8 Chapter 1 Getting Started with Compiled SCPI Running your First Compiled SCPI Program Reviewing getstrtl cs Program Figure 1 1 lists the get st rt 1 cs program in its entirety for your convenience getstrtl cs Print the identification of the module manufacturer and revision number uses C SCPI preprocessor commands include lt stdio h gt Standard Header Files We ge eae cB ee C SCPI Header File include lt cscpi h gt
109. point at a line number b 34 list routine name to view the source code dir source dir to add a directory to the search path Chapter 4 79 Troubleshooting Compiled SCPI Executing GDB To execute GDB at the command prompt enter the following gdb source2 where source2 is the name of your program You will enter the gdb program and will see the GDB prompt gdb At the prompt you need to first send the command to ignore signal 32 Then you set a breakpoint we have shown main as an example and run This will run the program to the breakpoint specified You can then single step through your program with the s command The following is an example of using GDB Sgdb test GDB is free software and you are welcome to distribute copies of it under certain conditions type show copying to see the conditions There is absolutely no warranty for GDB type show warranty for details GDB 4 15 96q1 i1386 unknown lynxos2 5 Copyright 1995 Free Software Foundation Inc gdb b main Breakpoint 1 at 0x267 file test c line 15 gdb run Starting program tmp test Kernel supports MTD ptrace requests Breakpoint 1 main at test c 15 15 id iopen vxi New process 65 thread 37 16 if id gdb 80 Chapter 4 Note Troubleshooting Compiled SCPI Trapping Errors with cscpi_error This section provides a guide to using the cscpi_error routine to trap VXI instrument run time errors With C
110. pported card See Appendix A Online Documentation for more information e For MESSAGE configurations C SCPI uses the SICL iprompt f function See the SICL documentation for more information e See also INST_SEND 106 Chapter 5 Compiled SCPI Command Reference INST_QUERY Example This example queries for a card description and stores the result The result of the card description query is stored in result INST _DECL vm E1411B R main int cardnum 1 char result 255 INST_STARTUP INST_OPEN vm vxi 24 INST_QUERY vm SYSTEM CDES d Ss cardnum amp result printf the vm card description s n result Chapter 5 107 Compiled SCPI Command Reference INST_READSTB INST_READSTB The instrument read status byte command places the results of a serial poll from the instrument specified by the id parameter in the address specified by the c_addr parameter Syntax INST_READSTB id c_addr Parameters Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1411B REGISTER assigns variable INST_READSTB vm amp stb polls E1411B
111. r When using the INST_QUERY or INST_SEND you are missing the one of the parameters in the argument list expected string When using INST_QUERY or INST_SEND the cmd_string is missing expected Missing a left parentheses expected Missing a right parentheses expected Missing a semicolon xpected identifier Missing the id parameter expected Missing a comma in the parameter list empty parameter Missing a parameter missing or extra Missing or extra double quote missing or extra Missing or extra single quote usage cscpipp 1 driver f datafile file The correct usage of the preprocessor is as stated only 1 file allowed You cannot specify more than one file for the preprocessor Compile and Link Errors Compile and Link errors can occur because of problems in your C SCPI program See Chapter 4 Troubleshooting Compiled SCPT for specific information on resolving compile and link errors Appendix E 147 Error Messages Run Time Errors Run time errors occur when running your executable code These errors can occur for various reasons You can include a cscpi_error function to trap instrument run time errors You can also check the cscpi_open_error global variable to see what type of open errors occur See Chapter 4 Troubleshooting Compiled SCPI for more information on these error checking techniques
112. ram Description Program Listing Using Compiled SCPI Interactive Functions Programming with Interactive Functions Since the interactive functions allow you to enter the SCPI commands at run time you can write your program to prompt the user for a SCPI command at run time An example program using the cscpi_exe function is described in this section This example is stored in the usr hp75000 demos cscpi directory See Chapter 5 Compiled SCPI Command Reference for examples of the other two interactive functions HP Embedded VXI Controller HP VXI C Size Mainframe HP E1411B Digital Multimeter This program sets up and initializes the HP E1411B Multimeter It prompts the user for an address and loops prompting for SCPI commands The SCPI commands are parsed by the Controller and executed by the HP E1411B Multimeter When a null string is entered the loop is exited This program demonstrates how you can use the C SCPI execute function in an interactive mode See Chapter 5 Compiled SCPI Command Reference for more details on the C SCPI execute call example6 cs This is a C SCPI example of using the interactive mode Th program is written to prompt the user for the SCPI command The command is then executed using the cscpi_exe function include lt stdio h gt include lt stdlib h gt include lt string h gt include lt cscpi h gt define LENGTH 1000 maximum length of SCPI command amp
113. re Voltmeter ____ END vm CONF VOLT DC 7 27 MAX Set up source _p END sour SOUR VOLT1 2 7000 Close switch gt END sw ROUT CLOS 101 UR CODE HERE Controller Multimeter Source Switch Configure Call Multimeter Driver Multimeter Call Source Driver Call Switch Driver YOUR CODE Set up Source Close Switch T I M E Interrupt Figure 2 7 When an Interrupt Occurs If you have any problems with your code because of interrupts we recommend you do one of the following Leave overlapped mode in its default mode OFF Use HP SICL function calls to temporarily block interrupts Use OPC to finish overlapping commands The last two items are discussed in the subsections that follow Chapter 2 43 Use the HP SICL Function Calls to Temporarily Block Interrupts interrupt off gt interrupt on gt Use OPC to Finish SCPI Commands Using Compiled SCPI Overlapped Mode You can place HP SICL calls around C code calls to temporarily block interrupts Once you complete your code you can re enable interrupts The following example places SICL function calls before and after the user code INS INS INS END vm CONF VOLT DC 7 27 MAX END sour SOUR VOLT1 2 7000 iintro YO END sw ROUT CLOS 101 ff UR CODE HE
114. roducts catalog for a list of available drivers available from your nearest HP Sales and Service Office or see Appendix A Online Documentation for more information type The parameter that defines the configuration type The configuration type can be one of the following keywords MESSAGE for HP IB or VXI message based configurations REGISTER for register based configurations If you have a register based card configured over HP IB the configuration type is MESSAGE e INST_DECL INST_EXTERN or INST_PARAM is required to declare the id parameter This declaration must be done before any use of the id parameter 92 Chapter 5 Example Compiled SCPI Command Reference INST_DECL e The contents of the driver parameter are ignored for MESSAGE configurations For those cards use the instrument name for example E1410A as the driver parameter This will increase program readability e It is good practice to use INST_DECL at the beginning of your program to ensure you are not declaring an instrument in the middle of an executable statement You can only use INST_DECL where you declare anormal C variable e See also INST_EXTERN and INST_PARAM This example declares a global variable for the HP E1411B Since the voltmeter is declared outside of a function vm is available anywhere in the program file INST_D E1
115. seceseeseecsaeceeeesneeees D Threads and Compiled SCPI Writing your Compiled SCPI Programs Compiling your Compiled SCPI Programs s es E Error Messages Compiled SCPI Preprocessor Errors cesceceeseceseeereeeeeeeneeeenees Compile and Link Errors 20 0 cece ieeeeeeeceneeeneeeseceseceseeeeeeeaeeaeenaeees Ruin Fime Errors jsiss o 3 cab eves naaa cea RE et aed ar a aTe F Other Documentation Contents 3 Contents 4 Getting Started with Compiled SCPI Getting Started with Compiled SCPI Welcome to the Compiled SCPI Standard Commands for Programmable Instruments User s Guide Throughout this guide Compiled SCPI is called C SCPI This guide provides detailed information about how to use Compiled SCPI Example Compiled SCPI programs and troubleshooting information is provided as well For information about specific VXI instruments see the instrument s user s manual or the online documentation provided Conventions Used This guide uses the following conventions Notation Description non italics Non italicized words within the Syntax description are literals That is enter them exactly as shown This includes non italicized braces and brackets Non italicized words and punctuation appear in COMPUTER FONT italics Italicized words within the Syntax description represent argument names program names or strings that you must replace with an appropriate value
116. system are as follows Requirements e LynxOS Real Time operating system e HP SICL software for LynxOS e HP Compiled SCPI Preprocessor all instrument drivers Learning Products The learning products you should have with your system include the following e LynxOS complete manual set e HP SICL complete manual set e HP Compiled SCPI HP Compiled SCPI User s Manual this document HP Compiled SCPI Online Documentation HP Compiled SCPI Example programs usr hp75000 demos cscpi Verify System Setup This section provides commands to verify that the required software is installed See Appendix B for C SCPI installation instructions LynxOS Real Time At the command prompt type the following command Operating System nite se This will display the version number of the operating system Release 2 5 0 or later of LynxOS Real Time is required to run the C SCPI software You should see something similar to the following 2 600 SICL for LynxOS At the command prompt type the following command devices In the list you should see the following device sicl_driver 4 Chapter 1 C SCPI Software Getting Started with Compiled SCPI Verifying your Compiled SCPI System At the command prompt type the following ident lib libcscip a When you execute this command information for the C SCPI preprocessor and each instrument driver installed on your system is listed e name of C SCPI software or Driver e versi
117. tact your local Support organization or an Internal SICL error has occurred 9 10 Internal SICL error has occurred Contact your local Support organization or 11 12 or System encountered a resource problem Contact your local Support organization 13 14 Instrument driver can not provide the This occurs when the instrument driver is not required information compatible with the version of C SCPI that is installed on your system Note Once you have resolved a run time error you MUST re run the C SCPI preprocessor and re compile and link your code Otherwise you will be using the same code you were before Chapter 4 75 Troubleshooting Compiled SCPI The cscpi_open_error variable is defined and declared in the cscpi h include file Therefore you do not need to declare it in your program Program Description source2 cs set voltmeter to measure DC volts query for the results and print the results Ad include lt stdio h gt include lt stdlib h gt include lt cscpi h gt INS ECL vm E1411B REGISTE j numb1 2 0 vm_dc INST_OPEN vm Vxi 24 if vm 0 printf open failed on vm n printf cscpi open error number d n cscpi_open_error exit 1 INST_SEND vm CONF VOLT DC f numb1 INS ERY vm READ f amp vm_dc This particular cscpi_open_error is error number 1 To resolve this error you will need to add INST_S
118. tem that is not supported by C SCPI and it does not have its own driver In this case you would have to communicate with the instrument s registers or write a driver for this instrument See Chapter 3 for an example program with embedded SICL calls Chapter 1 13 Getting Started with Compiled SCPI Learning About Compiled SCPI Maximum System Throughput with Compiled SCPI There are many levels of throughput which you can achieve with HP VXI The following table shows the relationship between card types ease of use and throughput Card Type and Programming Language Throughput and Ease of Use Message based card Message commands Standard throughput Easy to understand commands Register based card Command module to interpret SCPI commands Standard throughput Easy to understand commands Register based card Register programming Best throughput Difficult to program Register based card Compiled SCPI to interpret SCPI commands Better throughput Easy to understand commands Register based cards Compiled SCPI running in Best throughput Easy to understand commands Overlapped mode C SCPI provides both high throughput and ease of use However to get optimum throughput you must use the overlapped mode Using the overlapped mode allows you to execute several commands to different instruments in parallel See Overlapped Mode in Chapter 2 for more information on increasin
119. ter 2 35 Using Compiled SCPI Overlapped Mode Overlapped Mode The overlapped mode is a mode of operation which allows you to overlap commands addressed to different instruments so that they are executed in parallel The default mode overlapped off does sequential programming that is one command is started after the previous command has finished With the overlapped mode on however you can take advantage of long setup times and allow commands to overlap thereby achieving higher throughput Turning overlapped mode on and off only applies to register based instruments Message based instruments automatically operate in overlapped mode because they have their own processor While using the overlapped mode certain commands can be executed in parallel When the command is executed it begins the instrument function and completes it some time later with an interrupt service routine Meanwhile other commands may begin execution without having to wait for the instrument function to complete The overlapped mode can be turned on or off in your C program By default this mode is off See Using the Overlapped Mode on page 40 for a discussion on the C SCPI function that turns the overlapped mode on or off Determining if you Should use the Overlapped Mode The overlapped mode can provide an increase in system throughput Use overlapped mode for either of the following conditions Your configuration requires commands to be executed
120. th results should be a pointer type The SYST ERR command differs from the READ command in the previous example in that it returns two items error number and error message By placing the amp in front of err_nun the results of the query will be placed in the address of the variable err_num The query statement should be as follows INST_QUERY vm SYST ERR Sd s amp err_num err_msg Because err_msg is declared as a character array char it does not require the to be placed in front of it Note Once you have resolved a compile error you MUST re run the C SCPI preprocessor Otherwise you will be compiling the same code you were before Program Description source2 cs set voltmeter to measure DC volts query for the results and print the results if include lt stdio h gt include lt cscpi h gt INST_DECL vm E1411B REGISTER main char err_msg 100 int err _num INST_QUERY vm SYST ERR Sd s err_num err_msg Where To Go For More Information For this type of error you should check Chapter 5 Compiled SCPI Command Reference to review the syntax of the commands 72 Chapter 4 Troubleshooting Compiled SCPI Link Error Examples Error Message Undefined Symbol s iintron iunmap lintroff imap Resolution Determine if you have linked all the appropriate libraries your program needs This particular error
121. the variable vm_dc The query statement should be as follows INST_QUERY vm READ S amp vm_dc 70 Chapter 4 Troubleshooting Compiled SCPI Program Description source2 cs set voltmeter to measure DC volts query for the results and print the results include lt stdio h gt include lt cscpi h gt INST_DECL vm E1411B R ER j numb1 2 0 vm_dc END vm CONF VOLT DC S numbl1 ERY vm READ S vm_dc Note Once you have resolved a compile error you MUST re run the C SCPI preprocessor Otherwise you will be compiling the same code you were before Where To Go For More Information For this type of error you should check Chapter 5 Compiled SCPI Command Reference to review the syntax of the commands Error Message source2 cs In function main source2 cs 29 invalid type argument of unary Resolution Look in your program on line 29 to determine the C SCPI command in error In this example the C SCPI command in error is as follows INST_QUERY vm SYST ERR Sd s err_num err_msgqg Chapter 4 71 Troubleshooting Compiled SCPI Using Chapter 5 Compiled SCPI Command Reference look up the INST_QUERY command and make sure you have setup the parameters correctly The INST_QUERY command expects the parameter for the results of the query to be an address Therefore the parameters for bo
122. ultimeter as an external variable Program example2 cs represents a library where routines can be added to create your own driver for the Multimeter This program needs to be compiled separately from the main program file example2a cs Program example2a cs uses the ANSI C extern command to declare the function test 1 as external to the program Once declared as external to example2a cs then it can be called and executed Use the following steps to preprocess compile and link these programs E Run your C programs through the C SCPI preprocessor cscpipp example2 cs gt example2 c cscpipp example2a cs gt example2a c E Compile each file gcc c g mthreads example2 c gcc c g mthreads example2a c E Link the files gcc g mthreads o example2 example2 o example2a o cscpi_error o lcscpi lsicl Chapter 3 53 Programming with Compiled SCPI Program Listing example2 cs This programming incl incl incl xample uses th lt stdio h gt lt stdlib h gt lt math h gt ude ude ude include lt cscpi h gt INST_EXT ERN vm E1411 REGISTE testl1 define POINTS 10 float a POINTS float expected POINTS 0 1 0 0 0 0 te 9 int fail int i 0 INST_QUERY vm MEAS VOLT 10 fof if i 0 i lt POINTS i fabs a i expected i gt printf test point d failed i
123. unfamiliarity with the C SCPI command set or with just a simple typing error The following illustrates executing the preprocessor command cscpipp example2 cs gt example2 c Error Message source2 cs line 12 missing or extra Resolution Look in your program on line 12 for a missing quote Use Chapter 5 for command syntax In this program snippet the statement on line 12 is INST_SEND The INST_SEND command is expecting a string constant containing SCPI commands The string constant should be enclosed in quotes as displayed below INST_SEND vm CONF VOLT DC f numb1 66 Chapter 4 Troubleshooting Compiled SCPI Program Description source2 cs set voltmeter to measure DC volts query for the results and print the results include lt stdio h gt include lt cscpi h gt INS ECL vm E1411B R ER j numb1 2 0 vm_dc STARTUP EN vm Vxi 24 END vm CONF VOLT DC f numbl1 ERY vm READ S amp vm_dc Where To Go For More Information For C SCPI preprocessor syntax errors refer to the Chapter 5 Compiled SCPI Command Reference Detailed descriptions of the C SCPI commands and their usage are described there Usage Error Error Message Example source2 cs line 11 undeclared identifier source2 cs line 21 undeclared identifier Resolution Look in your program on line 11 to determine the
124. vice clear equivalent to the instrument selected by the id parameter INST_CLEAR id Parameters Description id The user variable name for the instrument This is the variable name that you assigned to the instrument in the INST_DECL or INST_EXTERN command Once the variable name is assigned you can use that variable to send information to the instrument For example INST_DECL vm E1410A MESSAGE assigns variable INST_CLEAR vm clears E1410A e For MESSAGE configurations C SCPI uses the SICL iclear id function See the SICL documentation for more information e With REGISTER configurations you might use this command in a signal handling routine You can set up the routine to be called in response to a signal that you generate such as a Ctrl C You might generate the Ctrl C if your program seems hung on an INST_SEND or INST_QUERY command 88 Chapter 5 Compiled SCPI Command Reference INST_CLEAR Example This example sends a device clear to the HP E1410A Multimeter ECL vm E1410A M main INST_STARTUP INST_OPEN vm vxi 24 INST_CLEAR vm Chapter 5 89 Syntax Parameters Comments Compiled SCPI Command Reference INST_CLOSE INST_CLOSE The instrument close command closes the I O channel of communication with a device and releases memory us
125. vided prints the error message and exits the program If you are using cscpi_error in a separate file you must compile and link both files e Run your C program through the C SCPI preprocessor cscpipp example cs gt example c e Compile each file gcc c g mthreads example c gcc c g mthreads cscpi_error c e Link the files gcc g mthreads o exampl xample o cscpi_error o lescpi lsicl When using cscpi_error some restrictions apply See the restrictions listed for the INST_ONSRQ command in Chapter 5 Chapter 4 83 Troubleshooting Compiled SCPI Notes 84 Chapter 4 Compiled SCPI Command Reference Compiled SCPI Command Reference This chapter contains a detailed description of the Compiled SCPI Standard Commands for Programmable Instruments command reference This chapter contains the following sections Compiled SCPI Macro Commands TNST CLEAR Cid nenad itu ct et ee Gh Page 88 SINS T CHOSE Gd ibe eed ohBe ke ihe beam Biel aad Page 90 INST_DECL id driver type orare inah aana A ER eens Page 92 INST_EXTERN id driver type 0 0 0 0 ccc ccc cece Page 94 INST_ONSROQ id C_fuUNCTION 6 cee Page 96 INST_OPEN id dev_addr 0 0000 cece Page 98 INST_PARAM id driver type 2 0 0 0 Page 100 INST_QUERY id cmd_string readfmt c_expr c_addr c_addr Page 102 INST_READSTB
126. vides some C SCPI programming examples to help you write your own programs with C SCPI Each program contains a list of equipment needed program description and a program listing You can copy any of these examples into your own directory and make changes The examples in this chapter are stored in the usr hp75000 demos cscpi directory This chapter contains the following sections Looking at an Example System Configuration Providing an Error Routine Programming with a Scanning Multimeter Programming with an External File Programming with a C SCPI Parameter List Storing Block Data in a Separate File the f Option Using C SCPI in the Interactive Mode Triggering with the HP Pentium Controller Looking at an Example System Configuration The configuration shown in this section can be used with the programming examples in this chapter See the C Size VXIbus Systems Installation and Getting Started Guide and the individual instrument user s manuals for wiring and connection information 48 Chapter 3 Embedded VXI Controller C Size VXIbus Programming with Compiled SCPI C Size VXIbus Instrument Instrument if C Size VXIbus X Instrument Embedded N P VXI Controller X y M l o 6 J o o Ulle U Oo O Oo Q LI

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