Description

The Allen-Bradley 1756-CP3 is a dedicated serial programming cable designed for the ControlLogix and SLC 500 controller families. It serves as the physical communication link between a controller's front-facing RS-232 port and a computer or other Data Terminal Equipment (DTE). This cable is essential for local programming, firmware updates, and troubleshooting when network-based communication, such as Ethernet or ControlNet, is unavailable or not yet configured.

Features

• Right-Angle Connector: Features a right-angle 9-pin female D-shell connector at the controller end, allowing for chassis door closure during operation.
• Null-Modem Configuration: Engineered for point-to-point serial communication, bridging transmit and receive pins between the PLC and PC.
• Compatibility: Designed for use with Logix 5550, 5560, and 5570 controllers, as well as SLC 5/03, 5/04, and 5/05 modular processors.
• Standard Interface: Compatible with standard PC COM ports or high-quality USB-to-Serial adapters.

Technical Specifications

Installation Guidelines

• Ensure the controller is powered or in a safe state before connecting or disconnecting the cable to prevent potential communication errors.
• The right-angle connector should be seated fully into the controller's front-facing port to ensure a secure connection.
• Avoid routing the cable near high-voltage power lines or heavy electromagnetic interference (EMI) sources to maintain signal integrity during data transfer.
• If using a USB-to-Serial converter, ensure the driver is correctly mapped to the COM port in your programming software (e.g., RSLinx).

FAQ

Is this cable compatible with USB ports?

The 1756-CP3 features a 9-pin serial connector. To use it with a modern computer lacking a native COM port, you must use a high-quality USB-to-Serial converter. Ensure the converter supports the DF1 protocol.

Can I keep this cable connected while the ControlLogix chassis door is closed?

Yes. The 1756-CP3 is specifically designed with a right-angle connector at the controller end to provide the necessary clearance for the chassis door to close while the cable is attached.