Product Description:

The EL3751-0000 is a multifunction analog measurement terminal manufactured by Beckhoff within the EL EtherCAT Terminals series. Installed on the I/O rail, it digitizes sensor signals so the controller can observe mechanical strain, temperature-dependent resistance, or low-level process voltages without external conditioning. By combining high-resolution conversion and fieldbus communication, the terminal supports deterministic closed-loop control and detailed data logging in distributed automation cells. It offers a single electrically isolated input channel and derives its operating power from the system E-bus, making it suitable for compact cabinet layouts. This arrangement also reduces the need for separate signal-conversion hardware elsewhere in the control cabinet.

Its front end is built around a Delta-Sigma converter that attains an internal rate of 1.28 MSps, allowing the module to oversample and filter noise before forwarding results. Effective conversion occurs within 100 µs, and the numerical word width of 24 bit plus a sign bit preserves microvolt and sub-ohm changes across the user ranges. The differential input path is equipped with a 30 kHz pre-filter and supports a programmable span of ±5 mV to ±30 V, so identical hardware can evaluate thermocouples, bridge transducers, or nominal control voltages without rewiring. The ground reference is treated differentially to minimize common-mode errors and improve signal integrity in mixed-noise environments.

For other sensor types, the channel offers a current span of ±20 mA, a strain-gauge bridge window of ±32 mV/V, and a resistance mode covering 0–65 kΩ. Samples are taken at 10 ksps, and the simultaneous architecture prevents phase shift between voltage, current, or bridge measurements captured in the same cycle. The single input channel simplifies wiring while still reporting true RMS data to the PLC. Supply power reaches the electronics through the EtherCAT E-bus, and the housing carries an IP20 protection class for installation inside standard control cabinets. This makes the terminal suitable for control tasks that require direct comparison of low-level analog signals within one cycle.