Allen-Bradley 1746-C9/A SLC 500 Rack Interconnect Cable

Configured for backplane-level chassis extension in SLC 500 modular systems, the Allen-Bradley 1746-C9/A (1746-C9/A rack interconnect cable) provides direct physical/electrical execution for parallel I/O bus extension between a main SLC 500 chassis and one adjacent expansion chassis.

Suffix Breakdown & Model Matrix

The 1746-C9/A is a fixed-geometry interconnect assembly within the SLC 500 expansion cabling set. No functional segmentation or electrical variant structure is defined beyond revision suffix “/A”. Signal routing and pin mapping are factory-defined for 50-pin parallel backplane transfer only.

Hardware Specifications

SLC 500 Backplane Expansion Signal Integrity Control

The 1746-C9/A implements direct parallel backplane signal extension across adjacent chassis frames using 50-pin differential routing architecture. Backplane bus continuity is maintained through fixed impedance cable geometry, with signal timing dependent on synchronous scan cycles of the SLC 500 CPU.

The expansion topology enforces single-drop configuration only, preventing multi-rack daisy chaining. Mechanical latch retention ensures stable connector seating under cabinet vibration profiles. Ground reference continuity is maintained through chassis bonding rather than independent shielding return paths.

Frequently Asked Questions (FAQ)

Q: Can the 1746-C9/A support more than one expansion chassis?
A: No. The cable is electrically defined for one main rack to one expansion rack only. Additional chassis require separate architectural configurations.

Q: Is the cable suitable for remote I/O placement beyond cabinet adjacency?
A: No. Signal integrity and timing are limited to adjacent chassis within 0.9 m physical separation.

Q: What happens if the cable is connected while power is applied?
A: Hot insertion is not supported. Backplane pin mismatch under energized conditions may cause bus corruption or module fault states.

Field Installation Guidelines

System power must be removed prior to installation to prevent backplane pin arcing. Align 50-pin connectors using keyed orientation guides before applying latch locking force. Maintain chassis adjacency within specified cable length without mechanical strain on the connector housing.

Cable routing should avoid parallel alignment with high-voltage motor or inverter wiring to reduce induced noise coupling on backplane conductors. Ensure both chassis are bonded to the same protective earth reference point to maintain signal return stability across the interconnect path.