EP1816-3008 by Beckhoff

The EP1816-3008 is produced by Beckhoff for the EP Digital Input Modules series and acts as a combined digital input and acceleration sensor node for EtherCAT automation. Its purpose is to convey machine state information to a controller by sampling discrete 24 V signals while simultaneously capturing motion vectors from two integrated three-axis accelerometers mounted at a 90° offset to each other. This dual-function device streamlines wiring on equipment where vibration monitoring and standard input tasks must occupy a single compact field module.

The module provides 16 digital inputs that comply with the Type 3 requirements of EN 61131-2, allowing one block to handle signals that might otherwise require multiple terminal strips. Each input draws only 3 mA from the sensor circuit and is debounced by an internal 10 µs filter to suppress contact chatter. Logic edges are recognized at a nominal control potential of 24 VDC, and the module reports an undervoltage condition whenever the supply falls below 18 V. The minimum cycle time on the EtherCAT bus is 500 µs, enabling high-speed detection of rapidly changing processes. A streaming rate of 2.5 kHz keeps acceleration data synchronized with discrete events. The maximum cable reach between the signal sources and input pins is 30 m, which helps preserve signal integrity across distributed machinery.

Network wiring uses two M8 shielded sockets in a daisy-chain arrangement, and the connections maintain 500 V of electrical isolation between the EtherCAT circuitry and the I/O domain. Field sensors can receive up to 0.5 A of auxiliary power from the module, avoiding additional power taps in the cabinet. Acceleration values are captured with 10-bit resolution, providing suitable granularity for impact detection and trend analysis. A 25-pin D-sub connector with UNC 4-40 hardware carries the mixed I/O signals and provides an accessible connection in confined mounting spaces.