While using 2 GPIB-PCI cards on a Fluke Met/Cal calibration system, I got an EADR error message. Fluke tells me that I should make sure the NI configuration has a different primary address for ech card. One card is common to all the test instruments (14 instruments) and the other card is solely for use by the Unit Under Test (UUT). I believe both had a primary address of '0' before so I changed one to '1'. We also had 2 laptops that also run this app and they use PCMCIA cards (2 in each laptop) which also have both primary addresses set to '0'. They work OK. Another concern is that during an IDN? query to an Hewlett-Packard 437B, I get a readback of 'HEWMEUT-QACKASD,HP 437C,,2.0'