Reliance Automax. In stock ships today. Network communications module. 57C404A. 57C404B. 57C404C. The Network Communications module provides the necessary hardware required to transmit control and status data between two or more AutoMax/DCS 5000 racks to create a distributed control system. The racks that make up the DCS-NET network are called \"drops\". Each drop connected to the network must contain a Power Supply module, a Processor module, and a Network Communications module. Master/slave software protocol. 4K word dual-port memory. On-board CPU. Multiple Network Connections.