EL3151 by Beckhoff

The EL3151 is an analog input terminal manufactured by Beckhoff for the EL EtherCAT Terminals series. It installs on a DIN rail beside other fieldbus devices and feeds voltage measurements directly into the EtherCAT process image, giving controllers real-time access to plant signals for closed-loop control and data acquisition tasks. The digitized value is presented to the controller as a 16-bit process-image word, while an 8-bit status field reports conditions such as an overrange signal or wire break.

This terminal offers 1 single-ended channel that is converted with a resolution of 16 bits, so each sample represents one part in 65,536 of the full-scale range. A front-end filter set at 5 kHz suppresses high-frequency noise before conversion, allowing accurate capture of dynamic signals. The terminal uses simultaneous sampling, meaning the analog value is latched when conversion starts rather than being scanned serially. This method eliminates phase error when multiple EL terminals share a synchronization pulse. Electrical isolation withstands a potential difference of up to 30 V between the signal and internal circuitry, helping protect downstream electronics from modest overvoltage events.

Integration into high-precision motion or measurement networks is aided by distributed clocks, with internal timing jitter below 1 µs. The input stage can sink up to 40 mA from the field circuit without exceeding linearity limits, supporting sensors that require modest excitation current. The housing has an IP20 protection rating, indicating a finger-safe but unsealed enclosure intended for installation inside a cabinet. It clips onto a 35 mm mounting rail and can be installed in any orientation to accommodate crowded enclosures. Power for the conversion logic is supplied through the E-bus backplane, eliminating the need for a separate logic power connection.