The National Instruments SCXI-1129 is a high-density 256 crosspoint Matrix Switch Module designed for versatile switching applications. This module features a maximum scan rate of 100 crosspoints per second and can be configured in multiple arrangements, including a 4 x 64, 2-wire switch matrix, or as four 4 x 16, two 4 x 32, or two 8 x 16, 2-wire matrix configurations. The SCXI-1129 is engineered to support both low and high voltages, employing relays with a thermal offset of less than 9 µV to ensure accurate low-voltage measurements. The module includes electromechanical, latching, and non-latching relay types. For high-voltage applications, the optional high-voltage analog bus backplane adapter from the SCXI-1357/1358 kit allows for simplified expansion without complex wiring when multiple modules are connected. Compatible terminal blocks for the SCXI-1129 include the SCXI-1336, SCXI-1333, SCXI-1335, SCXI-1337, SCXI-1334, and SCXI-1339.

When integrating the SCXI-1129 into an SCXI chassis, the installation process should begin from the far-right slot and continue leftward for subsequent modules. The operation of this module is facilitated by the NI-SWITCH driver software in conjunction with NI-DMM software, and it can be programmed through development environments such as LabVIEW, Measurement Studio, or Visual Basic. With dimensions of 7.8 x 1.2 x 6.8 inches (19.8 × 3.0 × 17.3 cm) and a weight of 1 lb. (725 g), the SCXI-1129 is compact yet robust for various measurement applications. Although designated obsolete, the SCXI-1129 remains available for purchase and repair through Apex Waves, supporting a three-year warranty.