Hi cws6805, Thank you for contacting National Instruments. Let me make sure I understand exactly what you are asking. The base address of your VME device is set using four parameters. I'm not sure what you mean by "P2A2, P2C2, P2A3, P2C3" but it sounds as if you are referring to pins A2, C2, A3, and C3 on the P2 connector. You need to test your device to find out what the base address is. You're not sure which address your instrument will use, so you want to add a VME device for each possible base address.
If this device is in a VXI chassis with a VXI controller, this method will not work. Those pins are used for -2V, Clock 10, Trigger Line, and ground. If this is the case, your VME instrument will not function properly in a VXI system. I'll assume that your VME instrument uses four other parameters to set the base address. If you add all 16 devices and then try to communicate with each device, then yes, you would be able to determine which device can communicate and therefore is the real device. You could then find out what the base address is for that device. Regards, David Shatila Applications Engineer National Instruments