EL3048 by Beckhoff

The EL3048 is an analog input terminal produced by Beckhoff within the EL EtherCAT Terminals series. Installed on a DIN rail in a modular I/O station, the unit digitizes low-level current signals and forwards the resulting data across the EtherCAT E-bus to the controller. By providing eight independent channels in a 12 mm housing, it consolidates sensor wiring and streamlines data acquisition for machine monitoring, process control, and building automation systems.

It accepts 8 single-ended current channels, and each channel is converted with 12 bits of resolution so the controller receives 4,096 quantization steps per signal. The sigma-delta converter completes one full scan in 1.25 ms, permitting time-aligned updates in applications that run faster than conventional PLC cycles. Each analog input passes through a hardware low-pass stage that attenuates frequencies above 1 kHz, helping suppress switching noise from nearby drives. The front end has an input impedance of 85 ?, so connected transmitters must be able to supply the required current without distortion. Communication and logic draw 130 mA from the internal E-bus, eliminating the need for a separate supply for the terminal electronics.

Each input channel accepts up to 40 mA, providing headroom above the normal measurement range without describing this value as contact current. The module supports 30 V of electrical separation between the field wiring and the logic domain. Its IP20 protection rating makes it suitable for installation inside an enclosed control cabinet. The module samples the channels in a multiplexed sequence referenced to a common ground, and the raw values are packed into a 2-byte status word and a 2-byte data word for each channel in the process image. A 35 mm mounting rail provides the mechanical interface, while spring-clamp terminals simplify field wiring and module installation. The narrow housing also reduces the rail space required for applications that need several analog measurement points.