ALLEN-BRADLEY Replacement 1747-DCM Direct Communication Module

The ALLLEN 1747-DCM Direct Communication Module is a Remote I/O bridge that links a supervisory PLC-5 or SLC 500 controller to a remote SLC 500 via the RIO (Remote I/O) network, enabling a distributed processing arrangement within Rockwell Automation's older SLC 500 ecosystem. Unlike a standard I/O scanner, the 1747-DCM does not scan its own backplane I/O; instead it passes the supervisory data to the distributed SLC processor residing at the remote location, effectively presenting the remote chassis as a logical rack to the supervisor. Catalog number 1747-DCM, the module is used to connect an SLC 500 fixed controller with expansion chassis or any SLC 500 modular controller to a supervisory ALLLEN PLC through the RIO Link. This configuration allows data exchange between the supervisory controller and remote SLC components as part of a distributed processing system. A conformally coated variant exists (1747-DCM-CC), and Rockwell has published discontinuation for that variant as of March 31, 2014. Common applications include integrating remote SLC 500 I/O groups into an AB control scheme via the RIO network and enabling direct communication between PLC-5/AB supervisory systems and distributed SLC-500 processors without local I/O scanning.