Digital I/O

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Digital I/O Trigger Config help needed

I don't understand how the Trigger Config works. It seems like it cannot act alone, first off, you must call DIO Config with a port list which sets it up for buffering (something I don't want to do). Second, you must connect it to something. If you connect it to a DIO Read, will it ever _not_ trigger? Don't you have to put a DIO Start in between? I can't seem to get the trigger to ever not trigger. I'm looking at the examples that come with the DAQCard I'm using, and they will not trigger unless the active high or low is there, however, my VI triggers every time. I only wish to use the Trigger to start some other operations, such as writing to a few ports, and then reading some data off two different ports fo
r different reasons. I only need one "scan" of that data, just one quick read of the 8 lines on both ports, after I have written to two lines on seperate ports. Is there a way to use the Trigger to simply spawn more events, or does it always want to start scanning and reading?
Charles Brian Quinn
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Only the 653x devices support trigger with the pattern i/o mode. I am assuming that is what you are using? The way pattern I/O works is that data transfer is controlled by a clock. That clock can be internally generated or externally provide, that is software selectable. You can configure start trigger. The examples that comes with LabVIEW: Buffered Pattern Input shows you how trigger config works. If you are doing output, there is a similar example. Keep in mind that different trigger options are start trigger: which once the trigger signal is received, then you will start transferring data (can be continuous or finite), stop trigger: You will acquire data continuously from the begining, once the trigger is received, x amount (predefined) of pretrigger dat
a and y amount (predefined) of post trigger data is stored. You can read more about trigger and 653x devices by reading the 653x user manual. Just from reading your description, it is not clear what device you are using or what mode you are referring to, but I hope this clears it up a little bit.
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