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Buy Allen Bradley 1756-CN2/B Series B ControlNet communication module for ControlLogix chassis. Original surplus and refurbished stock available, fast shipping, technical support for industrial automation retrofit and spare parts replacement.

Product: Allen‑Bradley 1756-CN2/B, ControlLogix ControlNet Interface Module, Series B. This 1756-CN2/B communication module connects ControlLogix controllers and remote I/O devices onto a ControlNet industrial network, supporting scheduled and unscheduled CIP communication for high‑reliability factory automation, process control and PLC system expansion. As a single‑slot chassis module, the 1756-CN2/B fits any empty slot inside standard 1756 ControlLogix racks and works seamlessly with Logix5000 control systems, Studio 5000 programming environment and RSNetWorx for ControlNet network configuration software.

The 1756-CN2/B features one BNC ControlNet port with a fixed communication speed of 5 Mbps, and an integrated USB 1.1 port for local module setup, diagnostics and firmware updates. The module supports up to 99 network nodes on one ControlNet trunk and provides a maximum of 131 CIP connections, of which 128 connections are available for standard user communication. It accepts quad‑shielded 1786‑RG6 coaxial cable, the standard ControlNet media for noise‑resistant transmission in heavy industrial environments.

Power consumption of the 1756-CN2/B is rated at 5.6 W, drawing 1100 mA from the 5.1 V DC backplane and 3 mA at 24 V DC. Operating temperature range covers 0 °C to 60 °C, suitable for most general industrial control cabinets. The module carries cULus certification and is approved for Class I, Division 2 hazardous location applications, making it widely used in oil and gas, chemical processing, food and beverage, power generation, material handling and assembly lines.

Our inventory includes original surplus and tested refurbished 1756-CN2/B units. Every 1756-CN2/B communication module we supply undergoes functional testing, backplane communication verification and network port inspection before shipment. If you are upgrading legacy ControlLogix systems, replacing a failed ControlNet bridge or sourcing backup automation spares, the Allen‑Bradley 1756-CN2/B is a reliable drop‑in replacement for older ControlNet interface hardware.

We also supply a full range of matching ControlLogix spare parts including power supplies, digital I/O modules, analog modules, backplanes and other ControlNet communication adapters such as 1756-CN2R, 1756-CNB and 1756-EN2T. Send your RFQ for 1756-CN2/B quantity, target price and delivery deadline. We can provide commercial invoice, packing list and required shipping documents for international delivery.

Technical highlights for 1756-CN2/B: single slot form factor, non‑redundant ControlNet interface, BNC coaxial connector, USB service port, compatible with all standard ControlLogix chassis, support for scheduled I/O messaging and produced / consumed tags over ControlNet. The module is open‑style and must be installed inside a suitable industrial enclosure to meet site safety requirements.

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FAQ
What is 1756-CN2/B? The 1756-CN2/B is a Series B ControlNet interface module for Allen‑Bradley ControlLogix PLC racks, used to link controllers and field devices on a ControlNet network. Is 1756-CN2/B redundant? Standard 1756-CN2/B is non‑redundant. If you need redundant ControlNet ports, select the 1756-CN2R variant instead. What cable does 1756-CN2/B use? Use 1786‑RG6 quad shield coaxial cable with BNC terminations for the ControlNet network. Can 1756-CN2/B work with Studio 5000? Yes, the 1756-CN2/B is fully supported in Studio 5000 and requires RSNetWorx for ControlNet network scheduling and configuration.

1756-CN2/B