1747-C11 | Allen-Bradley DH-485 processor-to-isolated link replacement cable with RJ-45 (0.3 m)

The Allen-Bradley 1747-C11 is a short communication cable designed to connect a DH-485 InView communication module to a single SLC controller, such as the SLC-5/01 or SLC-5/03. It features an RJ-45 connector and a length of 0.3 meters (1 foot), making it ideal for tight installations or cabinet applications with limited space. Its main function is to enable reliable data exchange for programming and control operations in legacy automation environments. The cable supports DH-485 protocol, which was widely used for communication in early Allen-Bradley PLC systems. Its build quality ensures minimal signal loss and robust mechanical performance. Despite its simplicity, it plays a crucial role in maintaining connectivity in many established industrial systems.

The 1747-C11 is specifically intended for use with SLC-5/01 and SLC-5/03 controllers and may not be directly compatible with the SLC-5/02 or SLC-5/05 models. These latter models often support different communication configurations or use different physical ports. SLC-5/05, for instance, includes Ethernet communication as a standard, which eliminates the need for DH-485-specific cables like the C11. While some users may adapt wiring for alternative models, such usage is not officially supported and could result in communication errors. It is strongly recommended to consult Rockwell documentation for verified compatibility. Using the correct cable ensures proper electrical matching and protocol compliance.

The 1747-C11 is equipped with a standard RJ-45 connector, commonly used for data communications, including DH-485 protocol-based networks. This 8-pin modular connector provides a secure and precise fit into compatible Allen-Bradley ports, ensuring stable electrical connections during operation. The connector housing is molded and strain-relieved to reduce the risk of cable damage due to movement or mechanical stress. Its compatibility with standard communication jacks simplifies installation and replacement in the field. Despite its appearance, the connector should only be used in DH-485 networks - not standard Ethernet - due to different signal configurations. Always follow manufacturer documentation when identifying ports and connections.

The 1747-C11 cable is designed for DH-485 (Data Highway-485) communication, a serial protocol developed by Allen-Bradley for multi-drop network configurations. This protocol is widely used in legacy SLC 500 and PanelView devices for peer-to-peer and master-slave data exchange. DH-485 operates over twisted-pair wiring and supports modest communication speeds suitable for discrete control applications. The cable ensures signal compatibility and electrical integrity within the DH-485 framework. It is not suitable for Ethernet, ControlNet, or DH+ networks. When used properly, it maintains reliable data integrity and device interoperability in long-standing industrial systems.

The 1747-C11 is still available through Rockwell Automation’s catalog and various authorized distributors, although it is considered a legacy product. Since many industrial environments still operate with SLC controllers and DH-485 networks, this cable remains in demand. Rockwell continues to support existing installations, but for newer systems, Ethernet-based communication is recommended. Despite its limited use in modern automation, the 1747-C11 is critical for maintaining and troubleshooting older equipment. Users are encouraged to keep spare units in inventory, as future availability may decline due to system migrations. Its continued presence on the market is driven by the longevity of SLC-based control systems.