Sensor multiplexers allow the signal delivered to an instrument to be scanned or switched between multiple sensors. The multi-channel testing of multiple sensors/samples increases sample throughput and the productivity of costly instrumentation. Sensor multiplexers (also called sensor muxes) can handle analog or digital signals. Some sensor multiplexers can handle up to 80 multiplexed analog inputs and provide 12, 16, 18, or 24-bit data. A fiber optic multiplexer bundles signals for transmission over optical fiber lines. It can access multiplexers capable of transmitting a number of different bandwidths along a single copper line. Electronic sensor multiplexers allow sample and reference data to be acquired at the same time (up to 8 simultaneous-sampling analog inputs), which is especially useful for high-precision process analysis. Buffered multiplexers can handle video data at high speeds with low power consumption and low noise amplification. A PXI multiplexer is designed for measurement and automation applications that require high performance and a rugged industrial form-factor. PXI is an acronym for PCI eXtensions for Instrumentation (PXI). A multiplexer circuit combines two or more digital signals onto a single line, using time-division multiplexing. The signals can be separated again by a demultiplexer circuit that is synchronized to the sensor multiplexer. A robot multiplexer enables designers to reduce the wiring complexity on robotic tools and vehicles. A data multiplexer can provide simultaneous sampling across multiple devices systems. A switch multiplexer can increase the channel count of a single instrument.
Sensor multiplexers can be time-division multiplexers (TDM) or code-division multiplexers (CDMA). When choosing a sensor multiplexer, important parameters to consider include: form factor, number and type of input channels, power requirements, data network requirements such as data rate, transmission distance, programmability, and environmental considerations such as moisture resistance and maximum temperature.
Several organizations maintain standards for sensor multiplexers. For example, the Institute of Electrical and Electronic Engineers (IEEE) maintains IEEE C37.94 for optical fiber interfaces between teleprotection and multiplexer equipment. The European Technical Standards Institute (ETSI) maintains a Technical Body for Transmission and Multiplexing called ETSI TM, which maintains standards on sensor multiplexers.