Keithley 2002, Руководство по калибровке

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Calibration Command Reference
3-14
3.6 Detecting calibration step completion
When sending calibration commands over the IEEE-488 bus, you must wait until the instrument
completes the current operation before sending a command. You can use either *OPC? or *OPC
to help determine when each calibration step is completed. (The example programs in Appendix
B use the *OPC command to detect when each calibration step is completed.)
3.6.1 Using the *OPC? Query
With the *OPC? (operation complete) query, the instrument will place an ASCII 1 in the output
queue when it has completed each step. To determine when the OPC response is ready, do the
following:
1. Repeatedly test the MAV (Message Available) bit (bit 4) in the status byte and wait until it
is set. (You can request the status byte by using the *STB? query or serial polling.)
2. When MAV is set, a message is available in the output queue, and you can read the output
queue and test for an ASCII 1.
3. After reading the output queue, repeatedly test MAV again until it clears. At this point, the
calibration step is completed.
3.6.2 Using the *OPC command
The *OPC (operation complete) command can also be used to detect the completion of each cal-
ibration step. In order to use *OPC to detect the end of each calibration step, you must do the
following:
1. Enable operation complete by sending *ESE 1. The command sets the OPC (operation com-
plete bit) in the standard event enable register, allowing operation complete status from the
standard event status register to set the ESB (event summary bit) in the status byte when
operation complete is detected.
2. Send the *OPC command immediately following each calibration command. For example:
:CAL:PROT:DC:ZERO;*OPC
Note that you must include the semicolon (;) to separate the two commands, and that the
*OPC command must appear on the same line as the calibration command.
3. After sending a calibration command, repeatedly test the ESB (Event Summary) bit (bit 5)
in the status byte until it is set. (Use either the *STB? query or serial polling to request the
status byte.)
4. Once operation complete has been detected, clear OPC status using one of two methods: (1)
Use the *ESR? query, then read the response to clear the standard event status register, or (2)
Send the *CLS command to clear the status registers. Note that sending *CLS will also clear
the error queue and operation complete status.
3.6.3 Generating an SRQ on calibration complete
An SRQ (service request) can be used to detect operation complete instead of repeatedly polling
the Model 2002. To use this method, send both *ESE 1 and *SRE 32 to the instrument, then
include the *OPC command at the end of each calibration command line, as covered in para-
graph 3.6.2 above. Refer to your controller's documentation for information on detecting and
servicing SRQs. The example calibration programs in Appendix B demonstrate how to use SRQ
to detect the end of each calibration step.