If you are using a National Instruments GPIB board, then you should have a program called the Interactive Control on your computer (ibic.exe) that comes with the driver.
Open ibic (it looks like a dos window) and run the commands that are listed on our web site at:
http://www.ni.com/support/gpib/max/ibic.htm
If the ibln command says your device is listening, then it may just be that the device doesn't respond to the *IDN? command, but rather to some other type of identification command.
