Allen-Bradley 1756-CP3/A RS-232 Programming Cable

The Allen-Bradley 1756-CP3/A, also cataloged as the 1756-CP3/A RS-232 programming cable, serves as the primary serial programming interface lead utilized to execute configuration, diagnostics, and controller communication across ControlLogix 555x/556x Logix5000 platforms. It provides direct electrical RS-232 signal transport between a PC serial port and controller programming port.

Suffix Breakdown & Model Matrix

• Base model: 1756-CP3 programming cable

• Suffix “/A” indicates revision level of cable assembly

• No functional segmentation beyond revision control is defined

Hardware Specifications

Backplane Bus Communication and Logix5000 Serial Link Behavior

The cable operates as a point-to-point RS-232 physical layer interface without protocol conversion. Signal integrity is governed by voltage-level compliance within RS-232 standard limits, with asynchronous serial framing used by Logix5000 communication stack.

Right-angle DB9 termination reduces mechanical strain in dense control cabinet layouts, maintaining connector retention under vibration and cable routing constraints.

No active electronics or buffering exist within the assembly; therefore, communication latency is strictly determined by controller UART timing and host serial port configuration parameters.

Frequently Asked Questions (FAQ)

Q: Does the 1756-CP3/A contain any active signal conditioning electronics?
A: No. The cable is a passive RS-232 physical layer interconnect without signal conversion or amplification.

Q: Can the cable support hot-swap during active controller programming sessions?
A: No. Connection or disconnection during active communication may interrupt serial session integrity and require re-establishment.

Q: Is the cable compatible with Ethernet or USB ports?
A: No. It is designed exclusively for RS-232 DB9 serial interfaces.

Field Installation Guidelines

Ensure both DB9 connectors are fully seated before initiating communication between PC and ControlLogix controller. Avoid mechanical stress on the right-angle connector to prevent pin deformation.

Route RS-232 cable separately from high-voltage or high-frequency switching conductors to minimize electromagnetic coupling. Maintain consistent shielding continuity along cabinet entry points.

Verify serial port configuration parameters (baud rate, parity, stop bits) match controller communication settings prior to diagnostic or programming sessions.