Allen-Bradley 1769-CLL3 CompactLogix Bus Expansion Cable

The Allen-Bradley 1769-CLL3, also cataloged as the 1769-CLL3 Compact I/O Bus Expansion Cable, operates as a dedicated hardware component for left-to-left rack interconnection within CompactLogix expansion systems. This cable extends the local backplane bus across separate Compact I/O module banks, enabling data transfer without requiring additional controllers.

Hardware Specifications

Backplane Bus Communication Performance

The module maintains signal integrity across the backplane bus communication link connecting adjacent 1769 Compact I/O chassis banks. Its internal conductor shielding minimizes noise coupling and crosstalk during high-speed data transmission between the primary controller and remote I/O modules. By extending the physical backplane bus, the assembly maintains deterministic throughput and consistent bus timing across expanded module banks.

Frequently Asked Questions

Q: Can the 1769-CLL3 cable be installed in a right-to-left or right-to-right orientation?

A: No. The cable features keyed physical connectors rated specifically for left-to-left bank orientation. Reversing the connection orientation causes mechanical misalignment and prevents proper pin contact on the bus expansion cap.

Q: Does the expansion cable require an external power supply?

A: No. The cable acts as a passive backplane extension and routes power directly from the system power supply module across the local bus ribbon.

Field Installation Guidelines

Mount the adjacent 1769 Compact I/O banks on standard 35 mm DIN rails or flat panel surfaces prior to attaching the expansion cable. Ensure that the total distance between the left end caps of both banks does not exceed the 1 m physical length of the cable. Align the keyed connector housing with the left-side backplane expansion port on the target module bank and press firmly until the locking mechanisms seat fully. Route the cable through dedicated wire ducts, keeping it separated from high-voltage power wiring, motor leads, and variable frequency drives to avoid electromagnetic interference. Maintain minimum bend radii along the cable run to prevent conductor fatigue and strain on the connector interfaces.