PXI Express Configuration Information

For PXI Express devices, NI-VISA must know the correct register operation sequence to obtain the slot the device is currently plugged into. After you insert a device into a PXI Express chassis and power on the device, the device reads the slot number from pins on the chassis and stores the number in a memory register. To configure the device and chassis automatically, this information must be read from the device memory. Use the NI-VISA Driver Wizard to define how to read this information.

The register operation sequence includes register reads and reads masked with a set value. When using reads masked with a set value, if the mask does not have the least significant bit set, the read value is masked and shifted to the right by the number of least significant bits in the mask that are not set. For example, the mask of 0x78 has binary representation 0b01111000. This reads the register value, masks it with this mask value, and then shifts the result three bits to the right.