Rockwell 1786-BNC Series B ControlNet Coaxial Cable Connector

Allen-Bradley 1786-BNC Series B ControlNet BNC Plug RG-6QS Connector

Product Overview

The 1786-BNC (Series B) is a specialized ControlNet network connector manufactured by Rockwell Automation. Specifically engineered for high-integrity industrial data links, this BNC (Bayonet Neill–Concelman) plug facilitates the critical connection between RG-6 quad-shield coaxial cables and ControlNet hardware. In complex automation architectures, the 1786-BNC ensures low-loss signal propagation and mechanical resilience. Its Series B designation reflects optimized manufacturing standards for gold-plated contact stability and nickel-plated housing durability, making it an essential component for distributed I/O systems and PLC-to-device communication where network uptime is paramount.

Technical Specifications

The 1786-BNC B is built to maintain the strict 75 Ω impedance requirements of the ControlNet physical layer.

• Manufacturer: Rockwell Automation / Allen-Bradley

• Model Number: 1786-BNC

• Series: Series B

• Connector Type: BNC (Bayonet-style)

• Compatible Cable: RG-6 Quad-Shield Coaxial (RG-6QS)

• Impedance: 75 Ω

• Frequency Range: DC to 5 MHz (optimized for ControlNet protocol)

• Insertion Loss: < 0.1 dB per connector

• Return Loss: > 20 dB (ensures minimal signal reflection)

• Housing Material: Nickel-plated brass for corrosion resistance

• Contact Pin: Gold-plated for superior electrical conductivity

• Operating Temperature: -40°C to +85°C (-40°F to +185°F)

• Storage Temperature: -40°C to +85°C

• Compliance: CE, UL, CSA, and RoHS

Typical Application Scenarios

• ControlNet Trunk Lines: Terminating main coaxial segments in large-scale distributed I/O networks.

• PLC Communication: Connecting 1756-CNB or 1756-CN2 modules to the network media.

• Legacy System Maintenance: Replacing aging connectors in SLC 500 or PLC-5 ControlNet architectures to restore signal quality.