Using a PXI-6562, can I acquire data with length determined by start and stop pattern triggers?

[Artybear]

Thanks for looking into the pause-trigger rearm times.

I've got the new driver installed, which comes with a new example for continuous acquisition. It seems that there is an added attribute to the driver, SamplesPerRecordIsFinite, which replaces the need for the software-reference-trigger that was required in older versions of continuous acquisition. Looks great!

I took the new example, and added start- and pause-triggers to the setup, and it seems to be working now. One thing I stumbled on for a while is the fact that the pause-trigger seems to be for levels (0 or 1) only, whereas the start-trigger and advance-trigger is for edges (R[ising] or F[alling]) only. I'm inferring that from the fact that the digital form of each trigger (as opposed to the pattern-match form) gives only the level and edge options, respecitvely. I'm confused about my options, because the documentation says this about all of the pattern-match triggers:

This string expression describes the pattern to be matched. This expression is composed of the following characters:

• X or x: Ignore the channel
• 1: Match on a logic 1
• 0: Match on a logic 0
• R or r: Match on a rising edge
• F or f: Match on a falling edge
• E or e: Match on either edge

But when I use "R" for the pause trigger, the continuous acquisition ignores the rising edge. When I use "1," it seems to behave as expected.

Is it true, as I'm guessing here, that "R," "F," and "E" are invalid options for the pause trigger pattern? If so, does that mean that the pause-trigger is continuously triggering and rearming when my CS line is high?

-Arthur

[Timothy_S]

Arthur,

The help documentation for the Pattern Match Pause Trigger does specify that it accepts the string values with X, 1, 0, R, F, and E, so it should allow it to accept those for the triggering of the Pause Trigger. I'll go a bit deeper to check for any caveats with that particular trigger type.  The Pause Trigger is not going to continuously trigger and rearm in this case, as it is going to control when it pauses (stops) the acquisition based on the given trigger type.

For this application, it sounds like the best approach would be to use a Digital Level Pause Trigger as the control with the CS Line's level going high and low as needed. We can set the CS line as the pause trigger source, and use the High Level 'trigger when' option so that the acquisition will pause when the CS line goes high, and unpause (acquire) when the CS line goes low.