Allen-Bradley 1756-L55M12 Controller Processor

The Allen-Bradley 1756-L55M12 is a core processing component within the Logix5555 series. This controller executes complex logic and manages high-speed automation tasks. It provides a flexible solution for distributed control systems. The unit integrates easily into standard ControlLogix chassis. Consequently, it remains a reliable choice for legacy system maintenance and upgrades.

Memory and Data Handling

This processor features 750 kilobytes of user memory for logic and data storage. Additionally, it reserves 208 kilobytes specifically for I/O memory operations. While this model lacks onboard non-volatile memory, it manages volatile data efficiently during active sessions. Users must utilize a 1756-BA1 lithium battery to preserve data during power loss. This configuration ensures consistent performance for medium-scale industrial programs.

Network and Communication Support

The 1756-L55M12 supports a wide variety of industrial communication protocols. It interfaces with EtherNet/IP, ControlNet, and DeviceNet networks seamlessly. Furthermore, it maintains compatibility with older DH+ and Universal Remote I/O systems. This broad connectivity allows the processor to bridge different hardware generations. It also supports redundant controller architectures through ControlNet media.

Electrical and Environmental Specifications

Allen-Bradley engineered this controller to withstand rigorous factory conditions. It features the following technical characteristics:

• Backplane Current (5.1V DC): 1.23 Amps
• Backplane Current (24V DC): 0.014 Amps
• Power Dissipation: 5.6 Watts
• Operational Temperature: 0°C to 60°C (32°F to 140°F)
• Isolation Voltage: 30V (continuous)
• Shock Rating: 30g (operating)