A/D Start Trigger Signal - Measurement Computing PCI-DAS6034 User Manual

PCI-DAS6034, PCI-DAS6035, and PCI-DAS6036 User's Guide

A/D START TRIGGER signal

Use the A/D START TRIGGER signal for conventional triggering (when you only need to acquire data after a
trigger event). Figure 7 shows the A/D START TRIGGER signal timing for a conventionally triggered
acquisition.
A/D Start Trigger
The A/D START TRIGGER source is programmable and may be set to any of the AUXIN inputs or to the
DAQ-Sync DS A/D START TRIGGER input. The polarity of this signal is also programmable to trigger
acquisitions on either the positive or negative edge.
The A/D START TRIGGER signal is also available as an output and can be programmed to appear at any of the
AUXOUT outputs. Refer to Figure 8 and Figure 9 for A/D START TRIGGER input and output timing
requirements.
Rising Edge Polarity
Falling Edge Polarity
The A/D START TRIGGER signal is also used to initiate pre-triggered DAQ operations (when you need to
acquire data just before a trigger event). In most pre-triggered applications, the A/D START TRIGGER signal
is generated by a software trigger. The use of A/D START TRIGGER and A/D STOP TRIGGER in pre-
triggered DAQ applications is explained next.
Start Scan
Convert
Scan Counter
Figure 7. Data acquisition example for conventional triggering
Figure 8. A/D START TRIGGER input signal timing
Figure 9. A/D START TRIGGER output signal timing
4 3 2
t
w
t = 37.5 ns minimum
w
t
w
t = 50 ns
w
21
Functional Details
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