Cannot get Labview to control relays

[olsont]

I am trying to control NI 9481 switch units.  The error I get is "Device identifier not specified in the list entry".  I am using Global virtual channels in a Do loop to build my channel list.  I then use the DAQmx flatten channel list to put this into a string.  I use this string in a DAQmx Switch Connect vi to attempt to close the switches.  This last VI is generating the error.  I have tried putting a device constant into my channel list, but they are different data types so it won't work.  Any ideas?

[Jeff_T.]

Hello,

The cDAQ-9481 is controlled with DAQmx but the drivers consider it a digital module so it must be controlled with the DAQmx Digital Output VIs.  For instance, if you write a "True" to cDAQ1Mod4/Port0/Line0, then channel 0 will be "switched" and CH0a will be connected to CH0b.  You can use the DAQmx shipping examples for digital I/O in LabVIEW as a guide for how to do this.  I would suggest looking at either of the examples Write Dig Port or Write Dig Chan.  These can be found by going to Help >> Find Examples and then navigating to Hardware Input and Output >> DAQmx >> Digital Generation.  This will provide the basic functionality for switching the relays.  I hope this helps but if you continue having problems please continue posting to this thread.

Best Regards,

Jeff Tipps
Applications Engineer
National Instruments