Keithley 2520, Service Manual, Page: 39 / 137

Model 2520 Pulsed Laser Diode Test System Service Manual Calibration 2-9
Viewing calibration dates and calibration count
When calibration is locked, only the UNLOCK and VIEW-DATES selections will be
accessible in the calibration menu. To view calibration dates and calibration count at any
time:
1. From normal display, press MENU, select CAL, and then press ENTER. The unit
will display the following:
CALIBRATION
UNLOCK EXECUTE VIEW-DATES
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2. Select VIEW-DATES, and then press ENTER. The Model 2520 will display the
next and last calibration dates and the calibration count as in the following
example:
NEXT CAL: 07/15/2002
Last cal: 07/15/2001 Count: 0001
Calibration errors
The Model 2520 checks for errors after each calibration step, minimizing the possibility
that improper calibration may occur due to operator error.
Front panel error reporting
If an error is detected during calibration, the instrument will display an appropriate error
message (see Appendix B). The unit will then prompt you to repeat the calibration step
that caused the error.
Remote error reporting
You can detect errors while in remote by testing the state of EAV (Error Available) bit
(bit 2) in the status byte. (Use the *STB? query to request the status byte.) Query the
instrument for the type of error by using the :SYST:ERR? query. The Model 2520 will
respond with the error number and a text message describing the nature of the error. See
Appendix B for details.
Aborting calibration steps
To abort a calibration step from the front panel, press the EXIT key. To abort a calibration
step via remote, send the :ABORt command.