Reliance Electric 57C413A Communications Memory Module PLC

Reliance Electric 57C413A Communications Memory Module is a 64K common memory card for AutoMax PLC racks, delivered as a slim backplane card with a memory circuit board, protective enclosure, and faceplate that plugs into the rack’s backplane in slot 0. As a Common Memory module, it acts as a bus arbiter and stores configuration data and common variables shared by Processor modules, enabling coordinated communication across a rack and, in multi-processor configurations, inter-processor data sharing. In a single-processor AutoMax rack, the 57C413A provides an additional 128K of memory for common variables beyond the processor’s local memory. The unit typically draws about 1.05 A at 5 V on the backplane and includes lithium battery-backed RAM to preserve contents during power interruptions; with the battery installed, data retention ranges from roughly 600 to 2000 days, while without the battery retention drops to about 130 to 400 minutes. The 57C413A family (including 57C413B and 57C423 variants) is part of Reliance Electric’s AutoMax/DCS-5000 line; the 57413 designation is an earlier 64K common memory upgrade that is functionally related to the 57C413 family. These modules store symbol tables and shared data for applications and configurations, and are designed to plug into the AutoMax rack to extend the system’s memory and improve multi-processor coordination.