Latching digital output

[Igor Partola]

I am using LabVIEW 7.1 and NIDAQmx Base 1.4 on Mac OS X.

I am trying to write a constant value to some digital ports, and it seems to work (I have basically customized one of the examples to write to six ports at once). The problem is that a few moments after the data is written it gets flushed. Is there a way to latch the data that I have written in the registers until the user decides to change it.

Thank you,
Igor

[LYu]

Hi Igor,

To understand the situation better, what kind of device are you using? Is the program modified from the "Write Digital Port.vi"? If so, this program should output the value specified by the user until the value is changed, since the Write VI is inside a while loop and continually reads the data in the control. I hope this will help.

Thanks,
Lesley

[Igor Partola]

Hi Lesley,

First off the issue got resolved but I am not sure how.

I did use dynamic/Write Digital Port.vi as the basis for my program, which is supposed to control a High Frequency Generator. The only change I made was that I made it write to six ports at once. I've tried this program a number of times up until last Thursday and had no luck with it. To my surprise when I opened it this Monday and ran it, it worked. I am not sure how that happened since the only thing that changed over the weekend is that the clocks were rolled forward an hour (to me this is a very absurd explanation of what happened).

However the fact is that now the values that I write to the digital registers in the card (which is 6508 btw), stay there even if I remove the loop and run the program once.

So thank you for your reply.
Sincerely,
Igor