Product Description:

The EL3174 is a four-channel analog input terminal developed by Beckhoff for the EL EtherCAT Terminals series. It digitizes voltage or current signals arriving from field sensors and transfers the data to a PLC across the EtherCAT backplane. By occupying only 12 mm of DIN-rail width and sharing system power through integrated feed contacts, the module provides a compact way to collect process variables close to the machine. In a control network, it isolates sensor wiring from the high-speed bus, preserving signal integrity and protecting upstream electronics.

Signal fidelity is supported by its 16-bit resolution, which provides 65,536 codes per conversion for detailed measurement. The terminal uses multiplex sampling, so a single successive-approximation register converter cycles rapidly through each input. With 4 analog inputs available, one terminal can read several pressure, temperature, or position transducers. A 5 kHz input filter suppresses high-frequency noise before acquisition, maintaining accuracy while keeping latency low. Samples are forwarded to the controller every 200 µs EtherCAT cycle time, a rate suitable for submillisecond closed-loop control.

The inputs support a 35 V common-mode limit. The current inputs have a 30 V destruction limit, while the corresponding limit for voltage inputs is 50 V. A shared ground arrangement uses differential connections for voltage channels and single-ended connections for current channels, helping reduce interference while current draw is capped at 40 mA per terminal. Nanosecond-level synchronization with network masters is achieved through distributed clocks, allowing coordinated sampling across multiple terminals. Data occupies a 16-byte process image in the host controller, and the housing carries an IP20 rating for installation inside protected control enclosures.