EL4112 by Beckhoff

The EL4112 is a two-channel analog output terminal produced by Beckhoff for the EL EtherCAT Terminals series. Installed on a DIN-rail I/O station, it converts digital process data from the EtherCAT bus into regulated current signals for actuators, valve islands, or transducers in distributed control systems. Each channel shares a single-ended ground reference, allowing straightforward wiring in compact control cabinets while still providing galvanic separation through the bus coupler.

The terminal delivers a programmable output span of 0 to 20 mA with a conversion granularity of 16 bits, so a controller can command 65,536 discrete current levels for fine torque, speed, or flow regulation. Internally, both channels sample and update at a maximum rate of 20 kSps; this high throughput supports fast control loops or waveform generation without aliasing. A minimum EtherCAT cycle time of 50 µs ensures that data words reach the terminal quickly enough to use that bandwidth. The output stages refresh simultaneously, eliminating phase skew between the channels, which is useful for coordinated multi-axis drives or differential control strategies.

The current driver supports a load resistance of less than 500 ?, so it interfaces directly with most industrial receivers without booster amplifiers. System power is routed through the terminal's power contacts, which are rated for 4 A, allowing several neighboring modules to share the same supply trunk. The electronics operate from 0 to +55 °C and can be stored from -25 to +85 °C. The housing carries an IP20 rating, which protects against finger contact with hazardous internal parts and the entry of solid objects larger than 12.5 mm. Process data appear to the PLC as two 16-bit words plus status bits, so configuration and diagnostics integrate with Beckhoff TwinCAT or other EtherCAT masters.