Overview
The Allen-Bradley 1756-L55 ControlLogix 5555 Processor is a core control module in Rockwell Automation’s ControlLogix platform. This processor is part of the ControlLogix product family (Series A) and provides scalable control for industrial automation systems, delivering reliability and efficiency in managing complex operations. The 1756-L55 processor module comes without any user memory but includes a 1756-BA1 battery, requiring a separate memory module such as the 1756-M13 for operation.
Key Features
- 100 MHz processor supporting up to 128 discrete and 128 analog I/O points
- Ethernet, ControlNet, and DeviceNet network support with RS-232 serial communication for ASCII, DF1, and Modbus protocols
- Low backplane current draw: 1.23 to 1.25 Amps at 5.1 Volts DC and 0.014 Amps at 24 Volts DC
- Compatible with 1756 ControlLogix chassis and integrates seamlessly with other ControlLogix modules
- Power dissipation of 5.6 to 5.7 Watts with thermal dissipation of 19.1 to 19.4 BTU per hour
- Industrial-grade design suitable for manufacturing, energy, and process automation industries
Technical Specifications
- Processor Type: 32-bit Logix 5555
- Internal User Memory: None (requires external memory module)
- Backplane Current: 1.23 to 1.25 A @ 5.1 VDC, 0.014 A @ 24 VDC
- Power Dissipation: 5.6 to 5.7 W
- Thermal Dissipation: 19.1 to 19.4 BTU/hr
- Operating Temperature: 0 to 60°C (32 to 140°F)
- Storage Temperature: -40 to 85°C (-40 to 185°F)
- Weight: 0.35 kg (12.5 oz)
- Communication: RS-232 serial port; T4 IEC temperature code
- I/O Capacity: Up to 128 discrete and 128 analog I/O points
Typical Applications
The 1756-L55 is ideal for complex control systems requiring:
- Large-scale distributed I/O configurations
- Multi-network factory automation and process control
- High-speed manufacturing and material handling systems
- Energy management and infrastructure automation
- Applications requiring redundancy and high availability in ControlLogix architectures
Compatibility & Replacements
Compatible With
- 1756 ControlLogix chassis (hot-swappable slot configuration)
- 1756-A series I/O modules (digital and analog)
- 1756-EN2xx EtherNet/IP communication modules
- 1756-CN2xx ControlNet interface modules
- 1756-DNB DeviceNet interface modules
- 1756-L series memory expansion modules (M12, M13, M16, M23, etc.)
- RSLogix 5000 / Studio 5000 programming software
- EtherNet/IP, ControlNet, DeviceNet networks
Replaces / Drop-In Replacement For
The 1756-L55/A directly replaces earlier 1756-L55 revision models. This unit is commonly paired with memory modules including 1756-M12, 1756-M13, 1756-M16, and 1756-M23 to form complete processor packages such as 1756-L55M12 and 1756-L55M16. Verify compatibility with your system integrator before ordering if upgrading from a different ControlLogix processor generation.
Works With
- RSLogix 5000 and Studio 5000 Logix Designer software
- FactoryTalk View and Rockwell Automation HMI platforms
- EtherNet/IP (Industrial Protocol)
- ControlNet and DeviceNet fieldbus protocols
- Remote I/O systems and redundant ControlLogix configurations
- 1747-CP3 and 1756-CP3 serial programming cables
