Purchase now: Allen Bradley 1746-C7 Interconnect Cable
Purchase now: Atlantechdrives provides you the 1746-C7, a highly critical chassis interconnect ribbon cable designed exclusively for the Allen Bradley SLC 500 automation platform. Measuring exactly 0.152 meters (6 inches) in length, this specialized cable is engineered to electrically and logically connect two adjacent 1746 I/O chassis (such as the 1746-A4, -A7, -A10, or -A13) mounted side-by-side in a control cabinet. When your initial chassis is full and you need to expand your machine’s I/O capacity, the 1746-C7 effortlessly extends the communication backplane, allowing the primary SLC processor to recognize, control, and seamlessly exchange data with the expansion modules as if they were in the exact same physical rack.
Technical Specifications of the 1746-C7
This interconnect cable is built with industrial-grade shielding to protect the high-speed backplane data from electromagnetic interference (EMI) commonly found in factory environments. It features rigid, keyed connectors at both ends to ensure proper insertion and prevent bent pins.
- Part Number: 1746-C7
- Component Type: Backplane Interconnect Cable
- Compatible System: Allen Bradley SLC 500 (1746 Series)
- Length: 0.152 meters (6.0 inches)
- Function: Connects two adjacent chassis side-by-side
- Maximum System Configuration: Up to 3 chassis (maximum 30 slots total)
- Connector Type: Multi-pin keyed ribbon connector
Expert Installation Advice: Chassis Alignment and Strain Relief
Connecting two SLC chassis requires mechanical precision to prevent hardware damage. Expert Tip: The 1746-C7 is very short (6 inches) because it is specifically designed for cabinets where the expansion chassis is mounted immediately to the right of the primary chassis. Never secure the second chassis tightly to your backpanel before connecting the cable. First, loosely mount the second chassis, plug the 1746-C7 cable securely into the right-hand port of the first chassis and the left-hand port of the second chassis, and ensure the connectors are fully seated and locked. Only then should you fully tighten the mounting bolts of the second chassis. If you mount the chassis first and they are even slightly misaligned, you will put severe mechanical strain on the ribbon cable, which will eventually tear the internal copper traces and cause intermittent backplane communication faults (often throwing a CPU Major Fault).
Maintenance and System Limits
When expanding your SLC 500 system using the 1746-C7, you must adhere to Allen Bradley’s strict architectural limits. An SLC processor can support a maximum of 3 connected chassis, totaling no more than 30 I/O slots. Furthermore, remember that while the 1746-C7 extends the communication data lines, it does not extend the power. Each expansion chassis must have its own dedicated power supply (such as a 1746-P1, P2, or P4) inserted into the left-most power supply slot to drive the modules in that specific rack.
Frequently Asked Questions (FAQs)
Q: What is the difference between the 1746-C7 and the 1746-C9 cable?
A: The 1746-C7 is 6 inches long and is used for connecting chassis side-by-side horizontally. The 1746-C9 is 36 inches (0.91 meters) long and is used when you need to mount the expansion chassis vertically (one below the other) in the cabinet.
Q: Can I hot-swap or unplug this cable while the PLC is running?
A: Absolutely not. Unplugging the backplane interconnect cable while the system is under power will instantly crash the processor, trigger a major fault, and potentially damage the backplane chips.
Do you need more references from this brand? Explore our full catalog of Allen Bradley here.
Utilize this short ribbon cable for side-by-side expansion of SLC chassis, such as linking a 1746-A4 to a secondary rack.
