National Instruments 782835-37 2-Wire PXI Matrix Switch Module

The National Instruments 782835-37 is a high-density 4x64, 2-wire PXI matrix switch module. It is also known as the PXIe-2737 unit. This module is designed for routing signals within automated test systems, that utilizes electromechanical relays for immediate switching operations. It features a switch health center that offers onboard relay count tracking, a temperature sensor, and functional and resistive relay self-tests to monitor system health and plan for predictive maintenance.

The NI 782835-37 supports a maximum switching voltage of 100 V (channel-to-channel and channel-to-ground) and a maximum switching power of 60 W or 62.5 VA. Each channel can handle a maximum switching and carry current of 2 A along with a minimum switching load of 20 mV/1 mA. The module offers a DC isolation resistance of 1 GΩ at 25°C and an initial DC path resistance of less than 1.3 Ω, which increases to 2.3 Ω at the end of life. Thermal electromotive force (EMF) is kept below 10 µV that ensures minimal interference in sensitive measurements.

The NI 782835-37 module features non-latching electromechanical relays with palladium-ruthenium, gold-covered contacts. It connects via a 160-position DIN 41612 male connector on the front panel. Power requirements include 24 W at 12 V and 3.6 W at 3.3 V. The module is PXI Express compatible that measures 21.6 cm × 2.0 cm × 13.0 cm and weighs 423 g. It operates in environments up to 55°C with 10% to 90% relative humidity and can be stored in temperatures ranging from -40°C to 71°C.

The 782835-37 matrix switch unit has a bandwidth of up to 10 MHz with both 1-wire 50 Ω and 2-wire 100 Ω terminations. It provides excellent open channel isolation and low channel-to-channel crosstalk along with typical isolation values of ≥81 dB at 10 kHz and crosstalk values of ≤-67 dB at 10 kHz. The relay operate time is typically 1 ms (maximum of 3.3 ms) and it can simultaneously drive up to 90 relays. The module's relays have a mechanical life expectancy of 1 × 10⁸ cycles and varying electrical life spans depending on the load conditions.

The module complies with various EMC standards that include EN 61326-1 and FCC Part 15B. It also adheres to safety standards such as IEC 61010-1 and UL 61010-1.