120
Creating and Running Custom Algorithms
Initializing Variables
Variable initialization can be performed during three distinct HP E1415
operations.
1. When you define algorithms with the ALG:DEFINE command. A
declaration initialization statement is a command to the driver’s
translator function and doesn’t create an executable statement. The
value assigned during algorithm definition is not re-assigned when
the algorithm is run with the INIT command. Example statement:
static float my_variable = 22.95;/* tells translator to allocate space for this */
/* variable and initialize it to 22.95 */
2. Each time the algorithm executes. By placing an assignment
statement within your algorithm. This will be executed each time the
algorithm is executed. Example statment.
my_variable = 22.95;/* reset variable to 22.95 every pass */
3. When the algorithm first executes after an INIT command. By using
the global variable First_loop your algorithm can distinguish the first
execution since an INIT command was sent. Example statement:
if( First_loop ) my_variable = 22.95 /* reset variable only when INIT starts alg */
Sending Data to the
CVT and FIFO
The Current Value Table (CVT) and FIFO data buffer provide
communication from your algorithm to your application program (running
in your VXIbus controller).
Writing a CVT element
The CVT provides 502 addressable elements where algorithm values can be
stored. To send a value to a CVT element, you will execute the intrinsic
Algorithm Language statement writecvt(<expression>,<cvt_element>),
where <cvt_element> can take the value 10 through 511. Note that the
default PIDB algorithm will use certain CVT elements (see “History Mode”
on page 79). The following is an example algorithm statement:
writecvt(O124, 330); /* send output channel 24’s value to CVT element 330 */
Each time your algorithm writes a value to a CVT element the previous
value in that element is overwritten.
Reading CVT elements
Your application program reads one or more CVT elements by executing the
SCPI command [SENSe:]DATA:CVT? (@<element_list>), where
<element_list> specifies one or more individual elements and/or a range of
contiguous elements. The following example command will help to explain
the <element_list> syntax.
DATA:CVT? (@10,20,30:33,40:43,330)
Return elements 10, 20, 30-33,
40-43. and element 330.
Содержание VXI 75000 C Series
Страница 2: ......
Страница 16: ...16 ...
Страница 18: ......
Страница 30: ...30 Getting Started Chapter 1 Notes ...
Страница 32: ...32 Field Wiring Chapter 2 Figure 2 1 Channel Numbers at SCP Positions ...
Страница 44: ...44 Field Wiring Chapter 2 Figure 2 11 HP E1415 Terminal Module ...
Страница 54: ...54 Field Wiring Chapter 2 Notes ...
Страница 61: ...Programming the HP E1415 for PID Control 61 Chapter 3 Programming Overview Diagram ...
Страница 124: ...124 Creating and Running Custom Algorithms Chapter 4 Figure 4 2 Algorithm Operating Sequence Diagram ...
Страница 136: ...136 Creating and Running Custom Algorithms Chapter 4 Notes ...
Страница 152: ...152 Algorithm Language Reference Chapter 5 Notes ...
Страница 304: ...304 HP E1415 Command Reference Chapter 6 Command Quick Reference Notes ...
Страница 308: ...308 Specifications Appendix A Thermocouple Type E 200 800C SCPs HP E1501 02 03 ...
Страница 309: ...Specifications 309 Appendix A Thermocouple Type E 200 800C SCPs HP E1508 09 ...
Страница 310: ...310 Specifications Appendix A Thermocouple Type E 0 800C SCPs HP E1501 02 03 ...
Страница 311: ...Specifications 311 Appendix A Thermocouple Type E 0 800C SCPs HP E1509 09 ...
Страница 312: ...312 Specifications Appendix A Thermocouple Type E Extended SCPs HP E1501 02 03 ...
Страница 313: ...Specifications 313 Appendix A Thermocouple Type E Extended SCPs HP E1508 09 ...
Страница 314: ...314 Specifications Appendix A Thermocouple Type J SCPs HP E1501 02 03 ...
Страница 315: ...Specifications 315 Appendix A Thermocouple Type J SCPs HP E1508 09 ...
Страница 316: ...316 Specifications Appendix A Thermocouple Type K SCPs HP E1501 02 03 ...
Страница 317: ...Specifications 317 Appendix A Thermocouple Type R SCPs HP E1501 02 03 ...
Страница 318: ...318 Specifications Appendix A Thermocouple Type R SCPs HP E1508 09 ...
Страница 319: ...Specifications 319 Appendix A Thermocouple Type S SCPs HP E1501 02 03 ...
Страница 320: ...320 Specifications Appendix A Thermocouple Type S SCPs HP E1508 09 ...
Страница 321: ...Specifications 321 Appendix A Thermocouple Type T SCPs HP E1501 02 03 ...
Страница 322: ...322 Specifications Appendix A Thermocouple Type T SCPs HP E1508 09 ...
Страница 323: ...Specifications 323 Appendix A 5K Thermistor Reference SCPs HP E1501 02 03 ...
Страница 324: ...324 Specifications Appendix A 5K Thermistor Reference SCPs HP E1508 09 ...
Страница 325: ...Specifications 325 Appendix A RTD Reference SCPs HP E1501 02 03 ...
Страница 326: ...326 Specifications Appendix A RTD SCPs HP E1501 02 03 ...
Страница 327: ...Specifications 327 Appendix A RTD SCPs HP E1508 09 ...
Страница 328: ...328 Specifications Appendix A 2250 Thermistor SCPs HP E1501 02 03 ...
Страница 329: ...Specifications 329 Appendix A 2250 Thermistor SCPs HP E1508 09 ...
Страница 330: ...330 Specifications Appendix A 5K Thermistor SCPs HP E1501 02 03 ...
Страница 331: ...Specifications 331 Appendix A 5K Thermistor SCPs HP E1508 09 ...
Страница 332: ...332 Specifications Appendix A 10K Thermistor SCPs HP E1501 02 03 ...
Страница 333: ...Specifications 333 Appendix A 10K Thermistor SCPs HP E1508 09 ...
Страница 334: ...334 Specifications Appendix A Notes ...
Страница 346: ...346 Glossary Appendix C Notes ...
Страница 388: ...388 Generating User Defined Functions Appendix F Notes ...
Страница 438: ...438 Index Writing the algorithm 129 values to CVT elements 120 values to the FIFO 121 Z ZERO CALibration ZERO 194 ...