EL3042 by Beckhoff

The EL3042 is a two-channel analog input terminal produced by Beckhoff within the EL EtherCAT Terminals series. It digitizes low-level current signals so a control system can monitor process sensors through the EtherCAT fieldbus. By connecting directly to the E-bus in a terminal stack, the unit occupies a 12 mm slice in the I/O row and provides electrical isolation between the backplane and connected transducers. Its compact housing allows the terminal to be installed alongside other EtherCAT I/O modules in an industrial control cabinet.

The terminal accepts 2 single-ended inputs that are sampled by a multiplex converter every 0.625 ms. A built-in filter limits the analog bandwidth to 1 kHz, reducing high-frequency noise before conversion. The module draws 130 mA of supply current from the E-bus, so its internal electronics do not require a separate power feed. The permitted common-mode voltage between the field wiring and logic circuitry is 30 V. Internal timing is handled locally because distributed clocks are not supported, so the network master must manage application-level synchronization. Both channels share the converter through a multiplex sampling scheme, and their input signals use a single-ended ground reference. The process image transfers two status bytes and two value bytes for each channel to the controller.

An input impedance of 85 ? determines the load placed on the connected signal source. The formatted result has a presentation width of 16 bits and a measurement resolution of 12 bits. The housing has an IP20 protection rating, providing protection against finger contact for cabinet installation while offering no sealing against water. Configuration data can be retained through CoE storage support, allowing stored parameters to remain available to the control system. Power for the analog section is supplied through the backplane, which reduces external wiring at the terminal. The local conversion architecture provides regular channel updates without adding dedicated clock synchronization hardware.