Allen-Bradley 1203-GK1 Communication Module Remote I

The Allen-Bradley 1203-GK1 Remote I/O Communication Module is a 24VDC, ScanPort-based interface that connects field devices to an Allen-Bradley PLC within a Remote I/O network. Identified by firmware revision FRN 2.06, the GK1 provides the communication link between a remote I/O rack and an AB controller such as a PLC-5 or SLC 500 over the 1203 Remote I/O bus. It belongs to the 1203 Remote I/O family, alongside 1203-GD1 and 1336-GM1 boards, and is designed for use in legacy AB installations that require distributed digital I/O expansion. Typical applications include adding digital inputs and outputs for machines, conveyors, and automation equipment located away from the primary PLC, where 24V DC field signals are standard. Configuration is performed with DIP switches to set basic communication parameters and addressing, enabling straightforward integration into existing AB systems. The GK1’s 24VDC supply requirement aligns with common remote I/O rack power practices in Allen-Bradley ecosystems; this module is installed in a Remote I/O chassis and communicates with the host processor to exchange I/O data, supporting the distributed control of field devices while keeping the main controller’s I/O footprint manageable.