EL3008 by Beckhoff

The EL3008 is an analog input terminal manufactured by Beckhoff for the EL EtherCAT Terminals series. Installed on an EtherCAT I/O strand, it digitizes low-level process voltages so that PLCs can read field signals through the high-speed E-bus backplane. The terminal supports single-ended measurements referenced to a shared ground, making it suitable for sensors and control loops that already use a common return conductor.

This model provides 8 analog inputs, and the internal converter scans every channel within a typical 1.25 ms conversion time. Each reading has a 12-bit resolution, which divides the full-scale range into 4,096 discrete values for consistent control accuracy. The permissible signal range is ±10 V, allowing direct connection to many industrial transducers without external scaling. An input filter with a cutoff frequency of 1 kHz attenuates higher-frequency noise before sampling, which improves measurement stability in electrically noisy cabinets.

Power for the terminal electronics is drawn from the system bus, with a typical E-bus demand of 130 mA. The housing has an IP20 protection rating, which guards against finger contact but requires installation in an enclosure for protection from dust and moisture. Total gain and offset deviations remain within ±0.3% FS, supporting tight control tolerances without frequent recalibration. The input stage has an impedance of >130 k?, minimizing the load on the signal source even when several channels are wired in parallel. The terminal uses multiplex sampling across its channels and provides a dielectric strength of 30 V between the input and supply circuits. It can operate at up to 95% relative humidity, and its process image contains two status bytes and two value bytes per channel. Distributed clock support is not included, so the terminal does not provide time-stamped acquisition through that feature.