Model 6487 Reference Manual Limit Tests and Digital I/O 8-21
If the instrument is programmed to perform an infinite number of measurements (arm
count or trigger count set to infinite), you cannot use the :DATA? command to return
CALC2 readings. However, you can use the :DATA:LATest? command to return the last
CALC2 reading after aborting the measurement process. After sending the INITiate com-
mand to start the measurement process, use the ABORt command to abort the measure-
ment process, then use :DATA:LATest? to return the last CALC2 reading.
Sending :DATA? or :DATA:LATest? without first sending INITiate will return “old” read-
ings or cause an error (-220) if limit is not enabled or there are no readings available.
E) :ARM:SOURce <name>
Typical “start of test” options:
• IMMediate — Test starts when LIMIT key is pressed.
• NSTest — Test starts when component handler pulls the SOT line low.
• PSTest — Test starts when component handler pulls the SOT line high.
• BSTest — Test starts when component handler pulls the SOT line high or low.
Programming example
The following command sequence will test DUT using the limit tests example shown in
Figure 8-2.
*RST ' Restore RST defaults.
CALC2:LIM:UPP 2e-3 ' Set upper limit for Limit 1 (2mA).
CALC2:LIM:LOW -2e-3 ' Set lower limit for Limit 1 (-2mA).
CALC2:LIM:STAT ON ' Enable Limit 1 test.
CALC2:LIM2:UPP 1e-3 ' Set upper limit for Limit 2 (1mA).
CALC2:LIM2:LOW -1e-3 ' Set lower limit for Limit 2 (-1mA).
CALC2:LIM2:STAT ON ' Enable Limit 2 test.
' Connect DUT to input.
SYST:ZCH OFF ' Disable zero check.
INIT ' Perform tests on DUT (one measurement).
CALC2:LIM:FAIL? ' Return result of Limit 1 test.
CALC2:LIM2:FAIL? ' Return result of Limit 2 test.