Product Overview

The Allen-Bradley 1756-L55M14 is a high-performance central processing unit belonging to the ControlLogix 5555 platform. Engineered for large-scale industrial automation, this module provides the computational power necessary for complex motion, sequential, and process control tasks. It features a memory capacity of 3.5 megabytes for user programs and data, alongside 208 kilobytes dedicated to I/O memory, ensuring smooth execution of intensive logic routines.

As a Series A controller, the 1756-L55M14 is designed for integration into any standard 1756 ControlLogix chassis. It utilizes a producer-consumer model, allowing multiple controllers to share the same backplane and communicate efficiently across distributed networks. While this model relies on volatile memory for high-speed processing, it supports external backup solutions to maintain data integrity during power cycles.

Technical Specifications

• Memory Capacity: 3.5 MB User Memory; 208 KB I/O Memory

• Backplane Current (5.1V DC): 1.25 Amps

• Backplane Current (24V DC): 0.14 Amps

• Power Dissipation: 5.7 Watts

• Thermal Dissipation: 19.4 BTU/hr

• Isolation Voltage: 30V (continuous), tested at 707V DC for 60 seconds

• Module Location: Any slot in the 1756 Chassis

• Weight: 0.36 kg (0.8 lbs)

• Dimensions: 14.5 x 14 x 3.5 cm

Network and Communication Support

The 1756-L55M14 provides versatile connectivity options through various 1756 communication modules. It supports a wide array of industrial protocols:

• EtherNet/IP and ControlNet: Ideal for high-speed data exchange and redundant controller configurations.

• DeviceNet: Facilitates connection to low-level plant floor devices.

• Legacy Integration: Supports Data Highway Plus (DH+), Universal Remote I/O (RIO), and DH-485.

• Specialized Protocols: Compatible with SynchLink for high-speed coordinated drive synchronization and Modbus via custom ladder logic routines.

Environmental and Durability Standards

Designed for rigorous industrial environments, the module adheres to the following tolerances:

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

• Storage Temperature: -40 to 85 °C (-40 to 185 °F)

• Relative Humidity: 5% to 95% (non-condensing)

• Vibration: 2 g at 10 to 500 Hz

• Shock Resistance: 30 g (operating); 50 g (non-operating)

• RF Immunity: 10V/m radiated and 10V rms conducted