Racal Instruments 1256E Manual page 184

Advanced SCPI Operations 8-20
utilizing open-drain drivers (virtually all 1260-series relay
cards), the readback signal will be pulled low by the driver
when the driver is enabled (high or on state). For relay
cards, the verification mask should be manually set to the
inverted mode of operation.
2. Issue a verification command for the relays or range of
relays of interest.
This process is illustrated with several examples. If the following
command was sent:
VERIFY:MASK (@2(0:10)),1
the 1256 would set the verification masks for plug-in module 2,
channels 0 through 10
command would do the same thing except set the same channels
to normal (non-inverted) feedback:
VERIFY:MASK (@2(0:10)),0
If a channel needs to be set to don't care, this is easily
accomplished by sending a value of "X" for the mask:
VERIFY:MASK (@6(5),7(10:15)),X
Assuming in the first example that the plug-in card located in slot 2
had channels 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, issuing the
following query:
VERIFY:MASK? (@2(0:12))
would return:
1 1 1 1 1 1 1 1 1 1 1 X X
which would indicate the masks for the first 11 channels were
inverting and the last two were don't cares. If this hypothetical
card had a bad relay on channel 11, issuing the command:
VERIFY? (@2(0:12))
would simply return:
OK
If on the other hand, channels 3, 5 and 11 were bad, sending the
same verification command would return:
2 : 3,2 : 5
1256E User Manual
to "inverted" feedback.
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