The National Instruments SCXI-1130 is a reed matrix and multiplexer switch module for SCXI systems. It provides 256 channels of high density signal routing and is used in automated test, multi point measurement, and instrument sharing applications where a large number of test points must be connected to a smaller number of instruments.
SCXI systems condition and route signals before they reach a DAQ device. The SCXI-1130 adds high density switching to this architecture. Reed relays provide fast, reliable switching with long contact life for low power signals, making the module suitable for production test and laboratory automation where many channels are scanned repeatedly.
Reed Matrix and Multiplexer Topology
The module provides 256 channels configured as a matrix or multiplexer depending on the application. A matrix allows multiple rows and columns to be connected in various combinations, while a multiplexer connects one common line to one of many channels at a time.
Engineers should review the specific topology and channel groupings in the product documentation. Grouping test points by signal type, voltage level, and measurement instrument helps control crosstalk and simplify software.
Signal Integrity and Switching Limits
Reed relays are well suited to low level signals, but they have voltage and current limits that must be respected. Engineers should verify switching voltage, current, and power ratings, and should confirm that the signals being routed remain within those limits.
Shielded cable, short lead lengths, and consistent reference connections help preserve accuracy for low level measurements. Cabling should be labeled by channel and routed away from high current conductors.
SCXI Integration
The module operates in compatible SCXI chassis with appropriate DAQ hardware. SCXI systems provide signal conditioning close to the sensors and route signals to a DAQ device. System design should consider chassis configuration, module placement, and cable routing.
A documented channel map is essential with 256 channels. Engineers should record which test point connects to which channel, along with the measurement instrument and range used.
Software Control and Sequencing
The module is controlled through NI switching software and standard programming environments. Engineers define connection paths, create sequences, and integrate switching with measurement tasks. Software should include connection validation, safe state behavior, and error reporting.
Settling time should be allowed between closing a path and starting a measurement. For high channel count scanning, the sequence and settling delays determine overall test time.
Applications
The SCXI-1130 is suited to multi point measurement, instrument sharing, component characterization, and production verification. It supports high density signal routing in an SCXI system.
Installation and Maintenance
Installation requires mounting the module in an SCXI chassis and connecting signal wiring according to the documentation. Wiring should be labeled and secured. The chassis should provide adequate cooling and protection.
Maintenance includes checking connectors, verifying relay operation on representative channels, and reviewing software configuration. Documentation of the channel map supports troubleshooting and repeatability.
Summary
The National Instruments SCXI-1130 Reed Matrix Switch provides 256 channels of high density signal routing for SCXI systems. It supports multi point measurement and instrument sharing with fast reed relay switching. Careful planning of topology, signal limits, settling time, and channel documentation makes the module a practical foundation for large scale test systems.
