The NI SCXI-1331 is a fully shielded terminal block engineered for SCXI-1127 and SCXI-1127 multiplexer and matrix switch modules. It features 84 screw terminals to support one-wire, two-wire and four-wire signal connections. An integrated cold-junction compensation sensor is equipped to deliver precise thermocouple measurement. Built with robust metal shielding, it resists electromagnetic interference. With high voltage and current tolerance, this terminal block fits industrial signal switching and matrix routing tasks. Its standard part number is 777687-31.

SCXI stands for Signal Conditioning eXtensions for Instrumentation, a modular signal conditioning platform. Products marked with 13xx are front-mounted terminal blocks for SCXI systems. SCXI-1331 is a dedicated terminal block with cold-junction compensation, specially matched with SCXI-1127 and SCXI-1128 switch modules.

This terminal block works with SCXI-1127 and SCXI-1128 modules. It has 84 screw terminals, including 64 signal terminals and 20 auxiliary and trigger terminals. The maximum rated voltage is 300 V under CAT II standard. Each channel can carry maximum 2 ampere for alternating and direct current. The built-in cold-junction compensation sensor works within 0 to 50 degrees Celsius. Its measurement accuracy reaches ±0.5 degrees Celsius between 15 and 35 degrees Celsius, and ±0.9 degrees Celsius in other temperature ranges of the operating scope. It supports three wiring modes, namely 64-channel one-wire connection, 32-channel two-wire connection and 16-channel four-wire connection.

It adopts standard SCXI physical dimensions. The terminal block is installed on the front of the target module and fixed by two thumb screws. The operating temperature ranges from 0 degrees Celsius to 50 degrees Celsius, and the storage temperature ranges from -20 degrees Celsius to 70 degrees Celsius. The applicable relative humidity is 5% to 90% without condensation. The full metal enclosure provides reliable protection against electromagnetic interference. The product complies with IEC 61010-1, UL 61010-1 and CAN/CSA-C22.2 No.1010.1 safety standards.

The front panel is arranged with multiple screw terminals for signals, ground lines and external trigger lines. The rear connector directly connects to SCXI-1127 and SCXI-1128 modules for signal transmission. No extra communication circuit or hardware setting is required. This terminal block operates in plug-and-play mode. It is compatible with NI-DAQmx driver, and supports LabVIEW, C/C++ and LabWindows/CVI development environments.

It supports flexible matrix wiring in one-wire, two-wire and four-wire modes to meet diverse signal switching demands. The integrated cold-junction compensation sensor guarantees accurate data collection during thermocouple temperature testing. It can withstand 300 V voltage and 2 A current, suitable for common industrial signal switching work. The metal shielding structure effectively suppresses external interference and maintains stable signal transmission in harsh working conditions. The screw terminals with strain relief design ensure firm connection and good vibration resistance for long-term operation.

It is applied to multi-channel signal scanning and temperature measurement systems using thermocouples and voltage signals together with SCXI-1127 and SCXI-1128. It serves custom matrix switching units for testing equipment in semiconductor, aerospace and automotive industries. It is widely used in industrial process monitoring to realize multiplexing of multi-point temperature and voltage signals. It also works for laboratory equipment calibration and general signal routing work.

Cut off all power supply before installation. Align the terminal block with the module connector, insert it steadily and tighten the fixing screws. Select qualified wires within standard gauge range for wiring, and connect the shielding terminal to earth ground. Set proper wiring topology in software according to on-site connection mode. When using thermocouples, enable the cold-junction compensation function in supporting software to ensure accurate temperature reading.

Place the device in a dry and ventilated area, and keep ambient temperature and humidity within the specified range. Conduct regular inspection to check loose screws, oxidized terminals and damaged wire insulation, and solve problems in a timely manner. All cleaning work must be carried out after power disconnection. Wipe the surface and terminals with anhydrous alcohol, and do not restore power until all parts are completely dry. For long-term storage, detach the terminal block, put it into an anti-static bag, and store it in a cool and dry environment.