Features:
- XT extreme temperature rating,Designed for harsh, extended‑temperature environments.
- 128 usable ControlNet connections,Out of 131 total, with 3 reserved for redundancy.
- Corrected rack-optimized fault handling,Outputs now go to Fault mode instead of Program mode.
The 1756‑CN2RXT B is built for ControlLogix‑XT systems, operating reliably in harsh environments where standard modules fail. It withstands wider temperature ranges and corrosive conditions, making it ideal for oil refineries, outdoor installations, and extreme climate zones. Always pair it with an XT‑rated chassis such as the 1756‑A5XT or 1756‑A7LXT.
The 1756‑CN2RXT B provides 131 total connections, but three are permanently reserved for redundant control. This leaves 128 connections for standard I/O and communication. The reserved connections always appear "in use" even when idle, so do not be alarmed. Plan your system knowing you have exactly 128 available connections.
Before firmware rev20.013, a rack‑optimized 1756‑CN2RXT B would send outputs to Program mode states instead of Fault mode during a communication fault. This could cause unexpected machine behavior. The corrected firmware now sends outputs to Fault mode as intended. If unable to upgrade, use direct connections as a temporary workaround.
The 1756-CN2RXT/B Allen-Bradley Interface Module may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Allen-Bradley 1756-CN2RXT/B Interface Module Manuals, Datasheets, Drivers, Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Allen-Bradley 1756-CN2RXT/B Interface Module Specs
General
- Manufacturer Allen-Bradley
- Model 1756-CN2RXT/B
- Condition New Original ready stock
- Product Family 1756‑CN2R/B,1756‑CN2/B,1756‑CN2RXT/D
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
- Energy and Resources: Such as oil and gas extraction platforms, wind turbines, and mining environments.
- Shipping and Marine Engineering: Suitable for shipbuilding and offshore facilities, addressing challenges of high humidity and salt spray.
- Critical Infrastructure: Used in monitoring systems with extremely high requirements for communication stability and redundancy, such as water treatment and power dispatching.
- Wide Temperature Range: Operating temperature range extended to -25°C to +70°C (-13°F to 158°F), with improved heat dissipation and ventilation design.
- High Connectivity: Supports up to 131 connections (128 for user use, 3 reserved for redundant control), suitable for large distributed I/O systems.
- Data Determinism: ControlNet provides highly deterministic and repeatable data transmission, ensuring that critical control commands (such as motion control or high-speed I/O) arrive within the scheduled time.
- Redundant Recovery and Stability: Series B improves recovery time after multiple connection interruptions and reduces state errors such as NET ERR through internal firmware optimizations.
- High Availability Control System: Symmetrical 1756-CN2RXT modules are installed in redundant racks as communication bridges between master and slave chassis. When the master communication cable fails, the module automatically switches to the backup channel without interrupting operation.
- Remote I/O Bridging: In remote, high-temperature environments far from the central control room, this module transmits remote I/O data across the ControlNet network back to the control center.
- Local Maintenance in Harsh Environments: Series B modules are equipped with an industrial-grade USB interface (replacing the older NAP interface), allowing maintenance personnel to directly connect to a laptop for temporary programming or diagnostics on-site.