Allen-Bradley 1756-L55M12 ControlLogix 5555 Processor Module 750KB

Product Introduction

When you need a reliable controller for complex automation tasks, the Allen-Bradley 1756-L55M12 provides a proven solution. This ControlLogix 5555 processor module from Rockwell Automation offers 750 Kbytes of user memory and 208 Kbytes of I/O memory. It supports up to 128,000 maximum I-O points, making it suitable for medium to large-scale systems. The module operates in temperatures from 0 to 60 degrees Celsius and withstands vibration from 10 to 500 Hertz. Its compact design weighs only 0.78 pounds (0.35 kilograms), easing installation in crowded cabinets.

Technical Specifications Breakdown

The 1756-L55M12 delivers key performance metrics that matter for industrial control. It features a program scan time of 0.08 milliseconds, ensuring fast logic execution. The backplane current draw is 1.23 Amps at 5 Volts DC and 14 milliamps at 24 Volts DC, which helps in power budget planning. For analog control, it handles up to 4,000 analog inputs and 2,000 analog outputs. The module uses a 1756-BA1 or 1756-BATM battery for memory backup. It also has a power dissipation of 5.6W and thermal dissipation of 19.1 BTU/hr, keeping heat manageable in enclosures.

Industry Applications

This controller excels in manufacturing lines, material handling, and process control where reliability is critical. Its support for multiple communication networks, including ControlNet, EtherNet/IP, DH+, DeviceNet, and universal remote I/O, makes it flexible for integrating with existing equipment. The 1756-L55M12 can be used in redundant controller systems when paired with a ControlNet network, providing high availability for mission-critical processes. Its 750KB memory handles complex logic and data logging tasks efficiently.

Installation & Setup Guidance

When installing the 1756-L55M12, ensure the backplane power supply meets the current requirements of 1.23 A at 5.1V DC and 0.014 A at 24V DC. Use compatible serial cables such as the 1756-CP3 or 1747-CP3 for programming. The module has an open style enclosure type rating, so mount it in a clean, dry environment within the specified temperature range. Verify that the communication ports are wired according to category 2 wiring standards. Always follow the manufacturer's guidelines for proper installation.

Maintenance & Reliability

To maintain reliable operation, inspect the 1756-L55M12 periodically for dust accumulation and ensure adequate airflow. The lithium battery (1756-BA1 or 1756-BATM) should be replaced only when needed to preserve memory. The module operates in relative humidity from 5% to 95% (noncondensing) and can withstand operating shock of 30 g. Regular testing of the controller's functionality helps prevent unexpected downtime. For long-term reliability, keep the controller within its storage temperature range of -40 to 85 degrees Celsius.

Compatibility & Integration

The 1756-L55M12 integrates seamlessly with other ControlLogix components and supports multiple communication protocols. It works with ControlNet, EtherNet/IP, DH+, DeviceNet, and universal remote I/O networks. This allows connection to various I/O modules, drives, and HMIs. The module is compatible with the 1756-CP3 or 1747-CP3 serial cables for programming. For redundant systems, pair it with another 1756-L55 controller on a ControlNet network. Verify compatibility with your existing system before ordering.

Buying Guide & Purchasing Advice

Before purchasing the 1756-L55M12, confirm that your application requires 750KB user memory and supports up to 128,000 I/O points. Check the backplane current budget to ensure your power supply can handle 1.23 A at 5V DC and 14 mA at 24V DC. Consider ordering a spare 1756-BA1 or 1756-BATM battery for future replacement. plcmatrix.com offers this module along with technical support to help you select the right components. Contact us for current availability and lifecycle status before placing an order.