Allen-Bradley 1785-L20C PLC-5 ControlNet Processor Module

The Allen-Bradley 1785-L20C PLC-5 ControlNet Processor Module is a ControlNet-capable processor designed for PLC-5 systems. This module provides the ControlNet communications interface within a PLC-5 rack, enabling data exchange between the PLC-5 controller and ControlNet devices. Identified by the 1785-L20C designation, it reflects a specific ControlNet processor configuration used in Allen-Bradley automation environments. The part is intended for use in legacy PLC-5 architectures where ControlNet connectivity is required for distributed I/O and device communication. As a dedicated ControlNet processor module, it manages communications traffic over a ControlNet network in concert with the PLC-5 processor, supporting the data transfer and protocol handling that underpins industrial control tasks. The 1785-L20C is part of Allen-Bradley’s PLC-5 family of ControlNet-enabled components, and is commonly selected for maintenance or replacement tasks within older automation installations that rely on ControlNet connectivity.