Create channels to log GPIB to tdms

Hi-

I have an application that is monitoring a GPIB device asynchronously.  I would like to parse the returned status from the GPIB device and create individual digital channels that are logged to a TDMS file.  I'm curious how i would define the virtual channel where i would be writing the data.  I'm familiar with DAQmx.Task.DIChannels.CreateObjRef.  Does the PhysicalName member have to be defined for the channel if I'm using this method?  If so, what would I use as the Physical name being that this is a GPIB device status that I'm interpreting and not discrete IO.   Not sure if there's a best practice for doing this and I didn't see any obvious references floating around the forum.

Thanks,

Ben