Digital input DAQ subroutine hangs LV

[littlesphaeroid]

I'm having fun wrapping up a new application, but I'm having an irritating problem. My app spawns four VIs that monitor four DAQ cards continuously. One of these monitors five lines on a digital input port. When this VI runs, the top-level VI hangs. I have done some tests and found that if I don't spawn this monitoring VI in the top-level VI, but rather run it in parallel, it will still hang the top-level VI (no user input is possible, although the indicators being updated by the other three monitors are updated.

When I quit the errant VI, the top-level VI becomes responsive again.

I've tried stripping down this routine to the barest essentials, I've changed the DAQ task from a port read to a line read, I've tried a variety of acquisition types (continuous, single measurement). All give the same result.

Other details: the card in question is a 9421 DAQ chassis card running over Ethernet. The other cards are 9207 and 9208 AI cards and a 9215 AI card. The main user interaction I'm trying to achieve is a digital out on three DIO cards. LV2011.

I'm not sure how to debug this further. I'm afraid I don't have enough DAQ experience to have encountered this before, as most of my prior experience is in GPIB...

[alcava.cr]

Hi there, This is a thread that is suppose to be posted in the Multifunction DAQ board. Thanks

[littlesphaeroid]

OK, I'll check there. But the DAQ board functions perfectly. It's LV that hangs up... so my feeling is it's a LV problem. In fact, the problem is the polymorphic mxDAQ Read function, since when I take that VI out, the hang goes away.... But let's see where this goes on the other board!

Thanks