Allen-Bradley 1756-L1M2 Logix5550 CPU Module

Product Introduction

The 1756-L1M2 is a high-performance processor module within the ControlLogix platform. This Logix5550 controller delivers 1 MB of user memory for logic and data storage. It does not include built-in nonvolatile memory. The module weighs approximately 0.35 kilograms, making it lightweight and easy to install. It occupies a single slot in the 1756 chassis. This controller handles both local and remote I/O effectively. Consequently, it suits a wide range of industrial automation applications.

Key Technical Specifications

This processor draws an average backplane current of 1.05 A at 5V DC. Meanwhile, it consumes only 0.02 A at 24V DC. The average power dissipation is rated at 4.8 W. Its thermal dissipation reaches 16.4 BTU/hour. The isolation voltage is 30V continuous with basic insulation. Additionally, the module has been tested to withstand 500V for 60 seconds. The 1756-L1M2 includes a replaceable battery. Specifically, it is compatible with the 1756-BA1 lithium battery only. For programming, you can use either the 1756-CP3 or the 1747-CP3 serial cable.

Memory and Storage Options

The 1756-L1M2 provides 1 MB of user-available memory. This capacity supports complex control logic and extensive data handling. However, the module does not include nonvolatile memory. Therefore, you must rely on the battery-backed RAM to retain programs during power loss. The onboard 1756-BA1 battery maintains memory content effectively. Regular battery checks are recommended for uninterrupted operation. Unlike some other models, this processor does not support external memory modules.

Communication Capabilities

This controller supports a broad range of communication networks. For instance, it works with DeviceNet and ControlNet networks. Additionally, it handles Universal Remote I/O for flexible system design. The 1756-L1M2 communicates with local and remote I/O seamlessly. Furthermore, it integrates with HMIs, SCADA systems, and other visualization platforms. Communication setup is defined through RSLinx software. This versatility makes the module suitable for diverse industrial environments.

Electrical Immunity and Robustness

The 1756-L1M2 offers excellent electrical immunity for harsh environments. It features ESD contact discharge immunity of 6 kV. Additionally, it provides ESD air discharge immunity of 8 kV. The radiated RF immunity is 10V/m with 1 kHz sine-wave 80% AM from 30 MHz to 1000 MHz. It also handles 10V/m with 200 Hz 50% Pulse 100% AM at 900 MHz. The EFT/B immunity is +/-4 kV at 2.5 kHz on power ports. For communication ports, the rating is +/-2 kV at 5 kHz. The conducted RF immunity is 10V rms with 1 kHz sine-wave 80% AM from 150 kHz to 80 MHz. These features ensure dependable operation in demanding industrial settings.

Mechanical and Environmental Ratings

The operating temperature ranges from 0 °C to 60 °C. In contrast, the storage temperature spans -40 °C to 85 °C. The relative humidity must stay between 5% and 95%, non-condensing. This module withstands vibration of 2G maximum peak acceleration at 10 to 500 Hz. Moreover, it handles an operating shock of 30G peak for 11 milliseconds. The non-operating shock rating is 50G peak for 11 milliseconds. The 1756-L1M2 is an open-style module. It carries an emission classification of Group 1, Class A. As such, it does not have a specific enclosure type rating.

Installation Guidelines

First, insert the module into any available slot in the 1756 chassis. You can install multiple controllers in the same chassis. These controllers communicate across the backplane while operating independently. The 1756-L1M2 occupies just one slot in the chassis. Power is supplied through the backplane from a ControlLogix power supply. Compatible chassis include the 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17. Always follow standard ESD precautions during handling and installation. The module is compatible with removable terminal blocks such as the 1756-TBCH and 1756-TBS6H.

Programming and Diagnostics

This controller supports IEC 61131-3 programming languages. For example, it works with Ladder Logic, Function Block Diagram, and Sequential Function Chart. Additionally, it supports Statement List programming. The front panel features diagnostic LED indicators. These lights report the module's operating status clearly. Consequently, troubleshooting becomes faster and more efficient.

Packaging List

• One Allen-Bradley 1756-L1M2 Logix5550 Processor module

• Factory-installed battery (1756-BA1 type)

• Product information leaflet

Shipping Information

All orders are dispatched via FedEx, UPS, or DHL. Express shipping is available for international destinations. Tracking details are provided after dispatch.

Frequently Asked Questions (FAQ)

1. What is the memory capacity of the 1756-L1M2?
The 1756-L1M2 provides 1 MB of user memory for logic and data storage. This capacity supports complex control applications effectively.

2. Does this processor support external memory modules?
No, the 1756-L1M2 does not support external memory modules. Program storage relies on the internal battery-backed RAM only.

3. What battery type is compatible with this module?
This processor works exclusively with the 1756-BA1 lithium battery. Do not use any other battery type, as it may cause malfunction.

4. Which programming cables work with the 1756-L1M2?
You can use either the 1756-CP3 or the 1747-CP3 serial cables. Both are category 3 cables compatible with this module.

5. What networks does this controller support?
The 1756-L1M2 supports DeviceNet, ControlNet, and Universal Remote I/O networks. This versatility allows flexible system integration across various platforms.