Detect identical USB equipment yet distinguish which USB card they

[labviewman]

I have 2 identical Agilent DMMs that are connected to the tester via USB. I can easily detect them via 'Find VISA Resource' using USB?*::0x0957::0x0618::?*::INSTR for the search item. Since the serial#'s of the DMMs are not fixed (DMMs will be replaced with identical equipment when calibration is needed), I can't use them (w/o some code to prompt the user to decide...which I hate do allow to make a decision) to determine which DMM I am talking to.

Since part of the output of the 'Find VISA Resource' gives the USB board it is plugged into I figured for $30 I can easily determine which DMM to use for function A (i.e. if the response is USB1, than I know DMM1 is connected to that USB port), but, it still returns back USB0. I now have 2 USB cards for a total of 8 USB ports, but 'Find VISA Resource' returns the same info on each port, and if I compare all the VISA properties I read on each USB port (with the DMM plugged-in), they are all identical.

I checked NI's site, but something is going on to their site...can't get into much of the knowledgebase and the forums are not working well.

I'm sure I'm not the first one to come across this, so I'm am hoping someone else can offer some advice.

Thanks,

Todd

[Karissap]

You could set VISA Alias names for each device using MAX.

You'd still have to update it when you swap instruments though but at least it's not a code change.