The **SST-SR4-CLX-RLL** is a specialized communication module developed by Molex (under the SST brand). It is designed to act as a high-speed interface between **Rockwell Automation ControlLogix** controllers and **Reliance Electric R-Net (Remote I/O)** networks. --- ### ## Core Specifications and Hardware Features The hardware is designed to fit directly into a standard ControlLogix (1756) chassis. Below are the primary electronic and technical components: | Feature | Specification / Description | | :--- | :--- | | **Module Type** | Single-slot ControlLogix module | | **Network Protocol** | Reliance Electric R-Net (Remote I/O) | | **Backplane Interface** | Standard 1756 ControlLogix Backplane | | **Processor** | High-speed dedicated FPGA/Microprocessor for protocol translation | | **Ports** | 1 x 9-pin D-Sub (RS-232) for Configuration; 1 x Network Connector | | **Isolation** | 500V DC optical/galvanic isolation between network and backplane | | **Current Draw** | Approximately 800mA @ 5.1V DC; 2mA @ 24V DC | --- ### ### Key Electronic Functionality 1. **Protocol Conversion Engine**: The core electronics perform "Scan-list" management. It mimics a Reliance Electric AutoMax processor to communicate with existing R-Net I/O racks, translating those signals into tags that the Allen-Bradley ControlLogix PLC can understand. 2. **Flash Memory**: The module contains onboard non-volatile memory to store configuration logic. This ensures that if the chassis loses power, the mapping between the R-Net I/O and the ControlLogix tags is preserved. 3. **Diagnostic LEDs**: The front panel includes electronic status indicators: * **OK**: Module health status. * **COMM**: Network activity indicator. * **ERR**: Hardware or configuration fault. --- ### ### Application in Systems This part is primarily used in **legacy migration projects**. Instead of rewiring an entire factory floor (which uses Reliance R-Net I/O), engineers replace only the aging Reliance processor with a modern ControlLogix PLC and this SST module. ```yaml System_Architecture: Controller: Allen-Bradley ControlLogix (1756) Interface: SST-SR4-CLX-RLL Legacy_Network: Reliance R-Net Devices: Remote I/O Racks, Drives, Local Stations ``` ---