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

PCI-DAS6034 & PCI-DAS6035 User's Guide

4.2.3 A/D STOP TRIGGER Signal

Pre-triggered data acquisition continually acquires data into a circular buffer until a specified
number of samples after the trigger event. Figure 4-6 illustrates a typical pre-triggered DAQ
sequence.
Figure 4-6. Pre-triggered Data Acquisition Example
The A/D STOP TRIGGER signal signifies when the circular buffer should stop and when the
specified number of post trigger samples should be acquired. It is available as an output and
an input. By default, it is available at AUXIN2 as an input but may be programmed for
access at any of the AUXIN pins or the DAQ-Sync "DS A/D STOP TRIGGER" input. It may
be programmed for access at any of the AUXOUT pins as an output.
When using the A/D STOP TRIGGER signal as an input, the polarity may be configured for
either rising or falling edge. The selected edge of the A/D STOP TRIGGER signal initiates
the post-triggered phase of a pre-triggered acquisition sequence.
As an output, the A/D STOP TRIGGER signal indicates the event separating the pretrigger
data from the post-trigger data. The output is an active high pulse with a pulse width of 50 ns.
Figures 4-7 and 4-8 show the input and output timing requirements for the A/D STOP
TRIGGER signal.
Figure 4-7. A/D STOP TRIGGER Input Signal Timing
t = 37.5 ns minimum
w
4–7
Functional Description