Product Overview
The Allen-Bradley 1746-C9 is a specialized 9-foot (approximately 2.74-meter) rack interconnect cable, a vital system component for the SLC 500 series programmable logic controller (PLC) platform from Rockwell Automation. This cable is not a standard network or communication cable; it serves the critical function of physically and electrically connecting two SLC 500 local I/O chassis to form an expanded local rack configuration. Its primary role is to extend the processor’s backplane, allowing a single SLC 500 CPU (such as a 5/03, 5/04, or 5/05) to address and control I/O modules distributed across multiple 4-slot, 7-slot, 10-slot, or 13-slot chassis. The Allen-Bradley 1746-C9 transmits power, data, and control signals between the chassis, enabling them to operate as a single, cohesive I/O system under the command of one processor module located in the primary chassis.Within the SLC 500 architecture, local expansion is a cost-effective method to increase I/O point count without transitioning to a more complex remote I/O network. The 1746-C9 cable is the essential link that makes this expansion possible. It connects to dedicated “rack interconnect” ports located on the rear of the SLC 500 chassis power supply. The “C9” designation specifically indicates the cable length. The value of the Allen-Bradley 1746-C9 lies in its OEM design and guaranteed compatibility; it ensures reliable, high-integrity communication between chassis, which is fundamental for deterministic I/O scanning and system stability. Using a non-genuine or incorrectly specified cable can lead to intermittent communication faults, I/O dropouts, or system crashes. For system integrators and maintenance teams, the genuine 1746-C9 interconnect cable is a key part of a reliable system build or repair, ensuring that expanded local I/O racks perform as a unified whole, maintaining the robustness and predictability expected from the SLC 500 platform throughout its long and successful service life.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1746-C9 |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Product Type | Rack Interconnect Cable |
| Compatible System | SLC 500 Series Programmable Controllers |
| Length | 9 feet (approx. 2.74 meters) |
| Connector Type | Proprietary molded connectors keyed for SLC 500 chassis |
| Connector Gender | Male to Male |
| Number of Conductors | Multi-conductor shielded cable |
| Shielding | Braided shield for noise immunity |
| Primary Function | Extends the SLC 500 backplane to a secondary local chassis |
| Maximum Local Racks | Allows connection of a primary and one expansion chassis (2 total) with standard processors; up to 3 chassis total with certain CPUs using two cables. |
| Data Transfer | Carries DC power, I/O data, and control signals between chassis |
| Voltage Rating | Carries system DC voltages from the primary chassis power supply |
| Operating Temperature | Standard industrial cable rating (e.g., 0-60°C) |
Main Features and Advantages
The Allen-Bradley 1746-C9 rack interconnect cable is defined by its purpose-built design for reliability and seamless integration. Its core advantage is guaranteed electrical and mechanical compatibility with the SLC 500 chassis. The proprietary molded connectors are precisely keyed to fit only the correct ports on the chassis power supply, preventing misconnection and ensuring all pins engage correctly. The cable’s internal construction is engineered to maintain signal integrity over its 9-foot length, carrying the multiple DC voltage levels (e.g., +5VDC, ±12VDC) and high-speed data signals necessary for backplane operation without crosstalk or excessive voltage drop. The inclusion of a robust braided shield is critical for protecting these sensitive signals from electromagnetic interference (EMI) and radio frequency interference (RFI) prevalent in industrial panels, preventing glitches in I/O communication.
