EL3011 by Beckhoff

The EL3011 is a single-channel analog input module from Beckhoff that belongs to the EL EtherCAT Terminals series. As an industrial I/O device, it digitizes a process current loop for closed-loop automation tasks. A controller on the EtherCAT network can read the resulting measurement data in real time.

This terminal accepts a current range of 0-20 mA and rejects unwanted offset with a maximum common-mode voltage of 10 V. Its sigma-delta converter completes a sample in 0.625 ms, and the result is quantized with a 12-bit resolution for a consistent step size across the full-scale value. The electronics draw only 130 mA from the E-bus, so multiple terminals can share a power segment without overloading the backplane. Sampling is simultaneous, meaning the channel captures the current value at the exact update instant, and a 1 kHz input filter attenuates higher-frequency noise before conversion. The differential input pair references ground internally, while a typical resistance of 85 ? plus the diode drop determines the burden on the current loop. Each update occupies 2 bytes of status information and 2 bytes of data in the process image, simplifying mapping within the PLC.

Protection against accidental contact is provided by the IP20 housing, which mounts on a 35 mm DIN rail. An operating range of -25 °C to +60 °C allows installation in most control cabinets. Reliable operation continues at up to 95% non-condensing humidity, and the module can be stored from -40 °C to +85 °C without performance loss. Converted readings are delivered as a signed integer with a 16-bit value that matches common controller data types. The measurement chain maintains an error of less than ±0.3% of full scale. Its simultaneous sampling architecture preserves channel timing when additional EL series I/O nodes operate on the same EtherCAT segment.