Reliance 57C404B Network Communication Module

The 57C404B Network Communications Module is the AutoMax network interface that links two or more AutoMax/DCS 5000 racks to form a distributed control system. Built for Reliance Electric AutoMax controllers, this module transmits control commands and status data across the AutoMax network, enabling coordinated operation of multiple racks within a single automation architecture. In typical installations, the 57C404B sits in the network path to bridge communications between processors, I/O racks, and remote nodes, supporting scalable expansion of a plant’s distributed control capability without replacing core CPUs. Key compatibility notes include: part number 57C404B; used with AutoMax/DCS 5000 family systems; originally manufactured by Reliance Electric, with the AutoMax lineage continuing to appear in legacy Reliance catalogs. Common applications encompass multi-rack process control and batch manufacturing lines where centralized logic governs multiple rack-based subsystems, or where data exchange between racks is required for synchronized control and monitoring. The module provides the dedicated hardware foundation for inter-rack communications that underpin distributed control in legacy automation environments.