Product Overview

The Allen‑Bradley 1786‑RG6​ is a premium quad‑shield RG‑6/U type coaxial cable specifically qualified by Rockwell Automation as the recommended transmission medium for ControlNet™ — the deterministic, producer‑consumer control network used extensively with ControlLogix®, CompactLogix™, Flex I/O, and legacy PLC‑5 and SLC 500 systems equipped with ControlNet interface modules (such as the 1756‑CN2/BR, 1768‑CNB, and 1771‑CN series). The 1786‑RG6​ features a 75‑ohm characteristic impedance, an 18 AWG solid bare copper center conductor, foam‑polyethylene (Foam‑PE) dielectric, and a heavy‑duty quad‑shield construction consisting of two layers of 100% overlap aluminum foil tape plus two layers of tinned‑copper braid (typically 60%/40% coverage), all enclosed in a gray, oil‑ and sunlight‑resistant PVC outer jacket. This shielding scheme provides exceptionally high rejection of electromagnetic interference (EMI) and radio‑frequency interference (RFI) encountered in industrial environments containing variable‑frequency drives, arc welders, and high‑current switchgear.In a ControlNet system the Allen‑Bradley 1786‑RG6​ forms the physical backbone — either as a trunk line connecting multiple nodes (coax T‑taps or splices with 1786‑BNC connectors) or as a drop cable from the trunk to an individual device. The network is terminated at both ends with 75‑ohm BNC terminators (1786‑XT) to prevent signal reflections. ControlNet’s 5 Mbps carrier‑band signaling over coax can span up to 300 m (1000 ft) between repeats/taps on a single segment, and with the use of repeaters (1786‑CPR) the total network distance can be extended considerably. The 1786‑RG6​ is sold in standard 305 m (1000 ft) reels and is the only cable formally certified by Rockwell Automation for ControlNet media; use of non‑qualified coax may result in marginal signal‑to‑noise ratios, increased bit‑error rates, and unpredictable network performance.Because ControlNet relies on precise signal integrity for its scheduled (implicit) and unscheduled (explicit) messaging, the Allen‑Bradley 1786‑RG6​ is engineered to tight attenuation and impedance tolerances (±2 Ω) and is tested to ensure compatibility with the full range of ControlNet node types, taps, and repeaters. Specifying the 1786‑RG6​ assures compliance with Rockwell’s published ControlNet media specificationsand helps guarantee the deterministic performance and noise immunity required by critical process and discrete automation applications.

Technical Specifications

Main Features and Advantages

ControlNet‑certified quad‑shield construction: The 1786‑RG6​ goes well beyond consumer‑grade RG‑6 by incorporating two foil shields plus two braid shields — a quad‑shield architecture that typically yields >90 dB shielding effectiveness through the MF/HF bands most relevant to industrial EMI sources. This is critical on ControlNet, where a compromised signal can cause NUT (Network Update Time) misses, red‑NUT transitions, or complete segment failure. Using the 1786‑RG6​ ensures the physical layer meets Rockwell’s certification criteria for ControlNet media.Precise 75 Ω impedance and low attenuation at 5 Mbps: Tight manufacturing tolerances keep the characteristic impedance at 75 Ω ± 2 Ω, minimizing impedance mismatches at T‑taps, BNC connectors, and terminators. Attenuation is specified and tested at the ControlNet carrier frequency to guarantee that even the furthest node on a maximum‑length segment receives a clean eye diagram. The foam‑PE dielectric and solid copper center conductor of the 1786‑RG6​ deliver stable performance over temperature and age, unlike copper‑clad steel (CCS) alternatives that can introduce higher loss and inferior solderability.Industrial‑grade gray PVC jacket for plant‑floor durability: The outer jacket on the 1786‑RG6​ is formulated for resistance to common industrial contaminants — including light oil mist, cleaning agents, and UV exposure in surface‑mounted tray or conduit runs — and carries a UL 1685 FT4 flame‑spread rating suitable for riser and in‑tray installation per NEC/CEC. Its distinctive gray color also aids visual identification as a ControlNet medium in mixed‑media cable trays containing Ethernet, DeviceNet (thick/thin), or analog signal cables.Full ecosystem compatibility: The 1786‑RG6​ is the cable specified in all Rockwell Automation ControlNet planning guides and is compatible with the 1786‑BNC BNC connector, 1786‑XT 75 Ω terminator, 1786‑CPR/CPS coax repeaters, and every ControlNet node released — from legacy 1771‑CN2 to current 1756‑CN2/BR and 1769‑CN. This eliminates uncertainty about whether a “generic RG‑6” will perform acceptably; the 1786‑RG6​ is the known‑good medium referenced in Rockwell’s own network validation testing.Support for standard and redundant ControlNet topologies: Whether deployed as a single trunk with T‑tap drops or as one of two independent coax segments forming a ControlNet Redundant Media (CNXR) configuration for fault‑tolerant architectures, the 1786‑RG6​ provides consistent electrical characteristics on both legs. In redundant pairs the cable is typically run in separate trays or conduits to maximize physical separation against localized damage.