Allen-Bradley 1747-C7 Communication Cable

The Allen-Bradley 1747-C7, also cataloged as the 1747-C7 Communication Cable, serves as the primary SLC 500 communication cable utilized to execute DH-485 physical layer connectivity across SLC 500 platform networks. The assembly provides DB9-based electrical signaling between controllers, programming terminals, and interface devices under RS-232-style DH-485 transport mapping.

Hardware Specifications

EtherNet/IP and DH-485 Communication Layer Coupling Behavior

Within SLC 500 architectures, the 1747-C7 cable implements shielded differential signal routing between DB9 endpoints while relying on external interface modules for protocol adaptation. Signal integrity is maintained through braided shielding and controlled impedance geometry. Electrical isolation is not performed within the cable assembly itself but is achieved when paired with 1747-AIC or 1747-PIC couplers.

The cable supports bidirectional serial framing for DH-485 token-passing networks where timing is governed by the controller and interface module handshake logic rather than the cable medium.

Frequently Asked Questions

Q: Does the 1747-C7 provide electrical isolation between devices?
A: No. Isolation is implemented in external interface modules such as 1747-AIC or 1747-PIC. The cable itself is a passive conductor assembly.

Q: Can the 1747-C7 be used for hot-swap connection under power?
A: The cable does not contain hot-swap circuitry. Connection or disconnection under live RS-232/DH-485 signaling may cause communication frame loss depending on controller state.

Q: Is the cable compatible with non-SLC 500 serial devices?
A: Electrical DB9 pinout is RS-232 style, but DH-485 signaling requires compatible interface logic; direct use with generic serial equipment is not supported.

Field Installation Guidelines

• Maintain separation between communication cable and high-voltage conductors to reduce induced noise coupling.

• Ensure DB9 connector locking screws are fully engaged (minimum mechanical retention before strain relief activation).

• Route cable with minimum bend radius consistent with shield integrity preservation.

• Verify shield continuity to designated chassis ground at one end only to avoid ground loop formation.

• Do not exceed recommended cable length beyond system specification for DH-485 timing stability.