Product Overview

The Allen-Bradley 1746-C9​ is a factory-manufactured, 1.5-meter (approximately 5-foot) interconnect cable specifically designed for the Allen-Bradley SLC 500 modular programmable controller system. This cable serves a critical, yet specialized, function: it physically and electrically connects the backplanes of two adjacent 1746 series I/O chassis, allowing them to operate as a single, unified I/O rack from the perspective of the SLC 500 processor. The SLC 500 system is modular, with a processor slot and I/O module slots housed in a chassis. When an application requires more I/O points than a single chassis can hold, the 1746-C9​ interconnect cable enables system expansion by daisy-chaining a second chassis. This connection transfers both power (for the logic circuits of the I/O modules) and the vital data communication bus from the primary chassis to the secondary chassis, seamlessly extending the controller’s I/O addressing space.The Allen-Bradley 1746-C9​ is an essential component for building cost-effective, medium-density control systems. It connects to a dedicated 50-pin connector port located on the side of compatible 1746-A series chassis (such as the 1746-A4, A7, A10, A13). By using this cable, system designers can create a local rack configuration where the processor in the first chassis communicates with I/O modules in both chassis as if they were all in one physical unit, without the need for additional communication adapters or complex network configurations. The 1.5-meter length provides flexible spacing between chassis within a control cabinet. The value of the Allen-Bradley 1746-C9​ lies in its simplicity and reliability; it provides a plug-and-play method for system expansion, ensuring signal integrity and power distribution between chassis with a robust, shielded cable assembly that meets Allen-Bradley’s stringent quality and compatibility standards, thereby guaranteeing system stability and performance.

Technical Specifications

Main Features and Advantages

The primary feature of the Allen-Bradley 1746-C9​ is its role as a seamless system extender. It provides a straightforward, hardware-based solution for expanding I/O capacity without introducing network complexity, additional IP addresses, or special configuration software. The cable is a factory-molded, shielded assembly with keyed connectors, ensuring a perfect fit and reliable connection that prevents mis-wiring and protects the sensitive data bus from electromagnetic interference (EMI). This plug-and-play design drastically reduces installation time and potential errors compared to field-wiring a custom cable with 50 individual conductors. The 1.5-meter length offers practical flexibility for arranging chassis within a control panel, allowing for optimal use of space and organization of wiring ducts.Reliability and system integrity are built into the Allen-Bradley 1746-C9. The cable is specifically engineered to maintain signal integrity for the high-speed digital communication traveling between the chassis backplanes. Proper shielding is critical in the noisy environment of an industrial control cabinet to prevent data corruption and I/O communication faults. By using this official interconnect, users ensure that power distribution to the secondary chassis is within specification, preventing voltage drop issues that could cause module resets or erratic behavior. The Allen-Bradley 1746-C9​ is a durable component designed for the long-term, static installation within a cabinet. Its use guarantees compatibility and performance that is validated by Allen-Bradley, supporting the overall reliability of the SLC 500 system. For maintenance, having a spare 1746-C9​ on hand is a common and cost-effective strategy for quickly resolving rare interconnect-related issues, minimizing system downtime.