DAqmx channel names - a problem?

[JackHamilton]

I am trying to programmatically create DAQmx tasks/channel names.

The problem is the new DAQmx task channel handles includes the Device name "Dev1/ai0".

I simply want to change the assigned Device for a already specified channel - You apparently can treat DAQ tasks/channels as strings and use string parsing to replace/update the channel content - but there are several problems.

1. The DAQmx channel are specific to the hardware type - ie. Analog, DIO and counter/timers have different prototypes. So the output of the string parser - has to be a string. It seems to work - I do see a coersion node at the string/channel connector.

2. The syntax for the Channel declaration is different! for analog it's "Dev1/aio" BUT for Timing the syntax is preceded by a "/" : "/Dev1/ctrOInternalClock".

So creating a VI to replace/update the "Dev" part of the channel is nearly impossible as I don't know a way to interrogate if the input channel is an analog, DIO or counter/timer type.

I don't think NI really though much about this...

[Michael Aivaliotis]

I simply want to change the assigned Device for a already specified channel - You apparently can treat DAQ tasks/channels as strings and use string parsing to replace/update the channel content

2904[/snapback]

This is interesting. Shouldn't there be a property node or something that you can use to re-assign a device? The reason why I say this is that I once had to swap a DAQ card out for another one. When I went into MAX, I saw my new card there and my old one was there listed with a red X thru it. When I deleted the old card from the list, MAX automatically prompted me and asked me If I wanted to swap all my tasks and global channels over to the new device.

I was very surprised and pleased about this. There may be a way to tap into this feature programmatically.

[JackHamilton]

Mike,

I looked *fairly thoroughly* thru the DAQmx channel and task property nodes and did not see a instance where I can change the device.

I ended-up hand coding all this with string tools - pretty sloppy as SOME tasks, like counter/timing required a "/" prefix before the 'Dev1" specification - or else you get an error when trying to create the channel.

I'm starting to see some DAQmx weirdness...and have been talking to NI support about this.