Reference Triggers - Measurement Computing Data Translation DT9857 User Manual

Chapter 6

Reference Triggers

DT9857 or DT9857E
External Positive TTL Trigger Support
SupportsPosExternalTTLTrigger
External Negative TTL Trigger Support
SupportsNegExternalTTLTrigger
Positive Threshold Trigger Support
SupportsPosThresholdTrigger
Negative Threshold Trigger Support
SupportsNegThresholdTrigger
Digital Event Trigger Support
SupportsDigitalEventTrigger
Sync Bus Support
SupportsSyncBusTrigger
Threshold Trigger Channel
SupportedThresholdTriggerChannel
Post-Trigger Scan Count
SupportsPostTriggerScanCount
a. Supported if the digital input port is included in the analog input channel list.
b. Supported if a counter is included in the analog input channel list.
c. Supported if the tachometer is included in the analog input channel list.
d. If you choose a threshold trigger for the reference trigger on the DT9857 or DT9857E module, you can program
the threshold level as a value between ±10 V for a gain of 1 or ±1 V for a gain of 10, and any of the supported
analog input channels can be used as the threshold channel.
If you choose a threshold trigger as both the start trigger and the reference trigger, the threshold channel and
threshold level must be the same. The polarity of the trigger (positive or negative going) can be different for each
trigger source.
e. You can specify how many post-trigger samples to acquire after the reference trigger by specifying the
post-trigger scan count in software.
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Table 19: Reference Trigger Options
A/D D/A
Yes
Yes
d
Yes
d
Yes
Yes
d
0 to 7 or 0 to 15
e
Yes
DIN DOUT C/T
a b
Yes Yes Yes
a b
Yes Yes Yes
a b
Yes Yes Yes
TACH QUAD
c
c
c