The National Instruments PCI-8331 (Part Number: 778956-01) is a highly efficient interface board that facilitates direct access and control of PXI systems from a PC. As part of the MXI-4 series, this card utilizes advanced MXI-4 technology to link two distant CompactPCI, PXI, or PCI buses via a data link that supports data transfer rates of up to 1.5 Gbit/s. With the NI PCI-8331, users can effectively control a CompactPCI/PXI backplane in conjunction with PXI or PCI-based systems, enabling physical separation between the automation or measurement system and the host PC. This capability is particularly beneficial for applications requiring additional slots, allowing users to expand their PXI or CompactPCI configurations.

The PCI-8331 is designed to operate seamlessly with MXI-4 software and the NI-VISA driver, which are included on the MXI-4 software CD or available via the National Instruments driver CD. This interface board supports only copper cable connections, with an allowable maximum cable length of 10 meters. Its dimensions are 4.2 x 6.9 inches, and it weighs approximately 0.42 pounds. The PCI-8331 adheres to PCI Specification Revision 2.2 and boasts an operating temperature range of 0 to 55 °C, alongside a storage temperature range of -20 to 70 °C. Additionally, it is rated for non-condensing humidity levels of 10 to 90% during operation and 5 to 95% during storage, with random vibration tolerances of 0.3 grms (operating) and 2.4 grms (non-operating) over a frequency range of 5 to 500 Hz. Although the PCI-8331 has reached obsolete status, it remains available for purchase and repair through Apex Waves.