Product Overview

The Allen-Bradley 1756-L55M22 is a high-performance central processing unit belonging to the ControlLogix 5555® family. Engineered for complex automation environments, this controller features a specialized dual-processor architecture. By separating duties between a Logix CPU for application logic execution and a dedicated Backplane CPU for I/O and communication management, the module ensures high-speed throughput and deterministic performance.

With 750 KB of user memory and 208 KB of non-volatile I/O memory, the 1756-L55M22 is designed to handle moderately complex discrete and process control applications. Its multitasking capabilities allow for the prioritization of critical control loops, ensuring that time-sensitive industrial operations are executed with minimal jitter and maximum reliability.

Technical Specifications

• Manufacturer: Allen-Bradley / Rockwell Automation

• Model Identification: 1756-L55M22

• Controller Series: ControlLogix 5555

• User Memory: 750 KB (Data and Logic)

• I/O Memory: 208 KB

• Communication Interface: Integrated RS-232 Serial Port (DF1, DH-485, ASCII)

• Supported Networks: EtherNet/IP, ControlNet, DeviceNet (via bridge modules)

• Chassis Slot Width: 1 Slot

• Current Draw: 1.25A @ 5.1V DC; 14mA @ 24V DC

• Operating Temperature: 0 to 60°C (32 to 140°F)

• Weight: 0.36 kg

• Dimensions: 3.5 x 14.0 x 14.5 cm

Advanced Connectivity and Integration

The 1756-L55M22 offers comprehensive network flexibility through its compatibility with various 1756-series communication interface modules. It facilitates advanced data sharing through "Produced/Consumed" tags, which allow multiple Logix controllers to share real-time data across EtherNet/IP or ControlNet without the need for complex messaging code.

For local configuration and maintenance, the module utilizes the 1756-CP3 or 1756-CP2 serial cables for direct connection to programming workstations running RSLogix 5000 or Studio 5000 Logix Designer software.

Reliability and Diagnostics