Product Overview

The Allen-Bradley 1770-CD is a high-performance twinaxial cable, colloquially known in the industry as "Blue Hose." It serves as the primary physical layer for legacy and high-reliability industrial communication networks, specifically Data Highway (DH), Data Highway Plus (DH+), and Universal Remote I/O (RIO). This specialized shielding cable is designed to provide a deterministic and noise-immune data path between programmable logic controllers (PLCs), human-machine interfaces (HMIs), and distributed I/O chassis across expansive factory environments.

Engineered to meet the electrical equivalent of Belden 9463, the 1770-CD is optimized for long-distance data transmission in areas with high electromagnetic interference (EMI). Its balanced twisted-pair architecture and comprehensive shielding make it a system-critical component for maintaining the signal integrity of real-time control networks.

Technical Construction and Signal Integrity

The 1770-CD is built to withstand the rigorous electrical demands of industrial automation, where data loss can lead to costly downtime.

• Shielded Balanced Pair: Features two insulated conductors twisted together and wrapped in an overall foil and tinned copper braid shield. This multi-layer protection minimizes signal cross-talk and blocks external RFI/EMI.

• Impedance Matching: Carefully controlled 78-ohm characteristic impedance ensures minimal signal reflection over long distances, which is vital for the high-speed timing requirements of DH+ and RIO protocols.

• Grounding and Drain Wire: Includes an integrated tinned-copper drain wire. For industrial safety and noise suppression, this must be terminated to a clean earth ground at each station connector to dissipate induced currents.

• Versatile Topology Support: Designed for use as both the main network trunkline (the backbone) and individual droplines (the segments connecting nodes to the trunk), providing a uniform cabling solution for the entire facility.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1770-CD

• Cable Type: Twinaxial (Shielded Twisted Pair)

• Network Compatibility: Data Highway, DH+, Remote I/O (RIO)

• Industry Cross-Reference: Equivalent to Belden 9463

• Impedance: 78 Ohms

• Conductor Gauge: 20 AWG

• Jacket Color: Blue

• Weight: 0.9 kg (approximate per standard reel unit)

• Bending Radius: Designed for flexible routing in industrial conduits

• Temperature Rating: Rated for standard industrial indoor environments

• Dimentions: 3.5x13x14.5cm

Installation and Best Practices

To ensure the highest system uptime, the 1770-CD should be deployed following strict Rockwell Automation guidelines.

• Physical Separation: Route the "Blue Hose" in dedicated conduits or trays, maintaining a minimum distance from high-voltage AC power lines and variable frequency drives (VFDs) to prevent inductive noise.

• Precise Termination: Ensure proper stripping of the blue outer jacket and foil shield without nicking the internal conductors. Termination into 3-pin connectors or D-shell adapters must be secure and checked for continuity.

• Termination Resistors: Always utilize the correct termination resistors (usually 82-ohm or 150-ohm depending on the baud rate) at the two physical ends of the trunkline to prevent signal ghosting.

• Durability: The rugged outer jacket is resistant to common industrial oils and coolants, ensuring the cable maintains its dielectric properties over years of continuous service.