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Model T940 User Manual
Publication No. 980938 Rev. K
Advanced Topics 8-44
Astronics Test Systems
o
Select the Channel Test to be used (1 of 4) on the Master and/or Slave
Sequencer for the channels to be ORed.
o
Unmask Channel Test for these channels.
o
Set the expect level for each channel to be the level desired for a trigger.
o
Select the TRG Bus to be used and select the Channel Test signal to drive it.
o
Do a Jump Test On the Master, select the same TRG bus signal and use a
“High” or “Rising Edge” test condition.
•
To do a Jump Test on the AND of several Channels:
o
Select the Channel Test to be used (1 of 4) on the Master and/or Slave
Sequencer for the channels to be ANDed.
o
Unmask Channel Test for these channels.
o
Set the expect level for each channel to be the complement of the level
desired for a trigger.
o
Select the TRG Bus to be used and select the Channel Test signal to drive it.
o
On the Master, select the same TRG bus signal and use a “Low” or “Falling
Edge” test condition.
Notes:
1. Local versions of the TRG signals are used when DSA and DSB on the same
module are linked. Thus Channel Tests will function as above without using the
backplane TRG Bus lines.
2. The TTLTRG Bus has a weak pullup, thus the risetime will be quite slow. As such,
the trailing edge of an active low signal will be delayed up to 40ns more than the
leading edge. Triggering on a falling edge is recommended when delay is a concern.
3. There is a way to do AND/OR or OR/AND channel tests between groups of channels
on different sequencers.
4. Since Aux Inputs can drive TRG Bus lines, they can be ORed. ANDed or even
combined with Channel Test signals in various ways. For example, an Aux. input
could be a qualifier for a Channel test.
5. When a TRG Bus line is configured to drive out an “ERROR”, a “Synchronization
Signal”, a “Sequence Reset”, a “Master Reset” or “Driver Disable” signal, the
corresponding input of these signals to the Master will be automatically configured.
6. The combination of up to 4 TRG Bus signals may be used to formulate a 1 of 16
“vector” to the sequencers so one can do a vectored jump to 1 of 16 locations based
on the state of these four signals.