Keithley 2520, User Manual, Page: 186 / 329

12-6 Common Commands Model 2520 User’s Manual
*TST? — self-test query
Run self test and read result
Use this query command to perform a checksum test on ROM. The command places the
coded result (0 or 1) in the Output Queue. When the Model 2520 is addressed to talk, the
coded result is sent from the Output Queue to the computer.
A returned value of zero (0) indicates that the test passed, and a value of one (1) indicates
that the test failed.
*WAI — wait-to-continue
Wait until previous commands are completed
Effectively, the *WAI command is a No-Op (no operation) for the Model 2520 and thus,
does not need to be used.
Two types of device commands exist:
• Sequential commands — A command whose operations are allowed to finish
before the next command is executed.
• Overlapped commands — A command that allows the execution of subsequent
commands while device operations of the Overlapped command are still in
progress.
The *WAI command is used to suspend the execution of subsequent commands until the
device operations of all previous Overlapped commands are finished. The *WAI command
is not needed for Sequential commands.
Table 12-4
*TRG programming example
Command Description
*RST
:TRIG:SOUR BUS
:TRIG:COUN INF
:OUTP1 ON
:INIT
*TRG Restore GPIB defaults.
Select BUS trigger control source.
Set trigger layer count to infinite.
Turn on output.
Take Model 2520 out of idle.
Trigger one measurement.