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

PCI-DAS6034 & PCI-DAS6035 User's Guide

4.2.2 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 4-3 shows the A/D START TRIGGER signal
timing for a conventionally triggered acquisition.
Figure 4-3. Data Acquisition Example for Conventional Triggering
The A/D START TRIGGER source is programmable and may be set to any of the AUXIN
inputs or 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. See Figures 4-4 and 4-5 for A/D START TRIGGER
input and output timing requirements.
Figure 4-4. A/D START TRIGGER Input Signal Timing
Figure 4-5. A/D START TRIGGER Output Signal Timing
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.
t = 37.5 ns minimum
w
4–6
Functional Description