Product Description:

The BK5120-0100 is an EtherCAT bus coupler produced by Beckhoff within the BK EtherCAT Bus Couplers series. It sits at the head of a terminal string and translates EtherCAT process data into parallel K-bus signals so that standard Beckhoff I/O terminals can be attached to a controller. By combining fast fieldbus access with modular terminal blocks, the unit provides a compact interface for distributed digital or analog inputs and outputs in industrial automation lines, and it forms both the logical and power boundary between the network and the I/O level.

It is powered from a system supply of 24 VDC, and the internal circuitry draws up to 500 mA under full load. A separate K-bus rail can source 1750 mA to attached terminals, while the power contacts route field voltage to downstream modules at currents up to 10 A. Data movement is organized in objects; the coupler exposes 16 Rx/16 Tx PDOs, allowing exchange of up to 64 bytes per cycle with the EtherCAT master. Signals enter through a single 5-pole connector, and spring-loaded Cage Clamp terminals secure the conductors. The power contacts remain at 24 V DC, and up to 95 % relative humidity is allowed as long as condensation is avoided.

Up to 64 I/O bus terminals can be installed behind the coupler, and their combined channel count may reach 960 inputs/outputs for discrete signals and 60 inputs/outputs for analog measurement or actuation. An internal back-up fuse rated at 10 A safeguards the power contacts against over-current events without affecting the K-bus feed. The housing measures 50 × 100 × 68 mm, so it occupies a width of just 50 mm on a DIN rail. Environmental ingress protection is limited to IP20, making cabinet installation mandatory. Within these boundaries the device maintains full EtherCAT performance while distributing field voltage and data to every attached terminal through the integrated cage-connected bus.