Allen-Bradley 1756-L1M1 ControlLogix Processor Overview

The Allen-Bradley 1756-L1M1 is a ControlLogix processor from the 5550 series. This controller provides 500 KB of data and logic memory for user programs and tags. It also includes 150 KB of I/O memory for input/output data storage. Additionally, the 1756-L1M1 offers 512 KB of expansion memory for larger applications. This module has an open-style enclosure rating. The controller weighs only 0.35 kg (12.5 ounces) for portable installation. Therefore, the 1756-L1M1 suits small to medium ControlLogix applications.

Memory Configuration

The Allen-Bradley 1756-L1M1 distributes memory across different functions. Data and logic memory reaches 500 KB for control programs and tag storage. I/O memory provides 150 KB for input and output data buffering. Expansion memory adds 512 KB for extended application support. However, note that the 1756-L1M1 does not have nonvolatile memory. Therefore, you need a battery to retain programs when removing power.

Battery & Programming Cable Requirements

The Allen-Bradley 1756-L1M1 uses a replaceable lithium battery. Compatible replacement battery is the 1756-BA1 weighing 0.59 grams. The controller requires the 1756-CP3 serial cable for programming. This cable must meet category 3 specifications. Therefore, use only approved accessories with the 1756-L1M1 for reliable operation.

Installation & Mounting

The Allen-Bradley 1756-L1M1 installs into any ControlLogix chassis slot. You can mount the controller in any available slot without restrictions. The chassis provides power and backplane communication to the 1756-L1M1 . The open-style enclosure suits installation inside a control cabinet. Consequently, the 1756-L1M1 offers flexible placement options.

Power & Current Specifications

The Allen-Bradley 1756-L1M1 draws power from the ControlLogix backplane. Backplane current at 5.1 Volts is 950 milliamperes (0.95 A) . Backplane current at 24 Volts is 20 milliamperes . Maximum power dissipation reaches 4.1 Watts at 60°C . Average power dissipation is 4.6 Watts . Average thermal dissipation reaches 15.6 BTU per hour . Isolation voltage rating is 30 Volts continuous . The module withstands 500 Volts for 60 seconds during testing.

Environmental Specifications

The Allen-Bradley 1756-L1M1 operates in standard industrial environments. Operating temperature ranges from 0°C to 60°C (32°F to 140°F) . Storage temperature extends from -40°C to 85°C (-40°F to 185°F) . Relative humidity tolerance reaches 5% to 95% non-condensing . Vibration tolerance ranges from 10 to 500 Hz with 2.0 G maximum peak acceleration . Operating shock withstands 30 G peak for 11 milliseconds . Storage shock withstands 50 G peak for 11 milliseconds .

EMC & Immunity Specifications

The Allen-Bradley 1756-L1M1 provides robust immunity for industrial environments. ESD contact discharge immunity reaches 6 kV . ESD air discharge immunity reaches 8 kV . Radiated RF immunity reaches 10 V/m with 1 kHz sine-wave 80% AM from 30 MHz to 1000 MHz. Additionally, radiated RF immunity reaches 10 V/m with 200 Hz 50% pulse 100% AM at 900 MHz. EFT/B immunity reaches ±4 kV at 2.5 kHz on power ports. EFT/B immunity reaches ±2 kV at 5 kHz on communication ports. Conducted RF immunity reaches 10 Vrms with 1 kHz sine-wave 80% AM from 150 kHz to 80 MHz. Therefore, the 1756-L1M1 performs reliably in electrically noisy environments.

Key Features & Benefits

• 500 KB data/logic memory – The 1756-L1M1 handles moderate control applications.

• 512 KB expansion memory – Provides room for application growth.

• Lightweight design – Weighs only 0.35 kg for easy handling and installation.

• Flexible slot mounting – Installs in any available ControlLogix chassis slot.

• Replaceable battery – Uses standard 1756-BA1 lithium battery for memory backup.

• High immunity – ESD, RF, and EFT ratings ensure reliable operation.

Installation Guidelines

Follow these steps to install the Allen-Bradley 1756-L1M1 correctly. First, power down the ControlLogix chassis completely. Second, select any available slot in the chassis for the processor. Third, align the 1756-L1M1 with the card guides in the chassis. Fourth, push the module firmly into the backplane connector until fully seated. Fifth, secure the module with the retaining screws at top and bottom. Finally, connect the 1756-CP3 serial cable to the programming port.

Install a 1756-BA1 battery before removing chassis power. Set the keyswitch to the desired mode before applying power. The 1756-L1M1 requires no special software beyond standard RSLogix 5000.

Package Contents

Your shipment includes the following items:

• 1 x Allen-Bradley 1756-L1M1 ControlLogix processor module

• 1 x Installation instructions manual

No battery is included with the 1756-L1M1 . Therefore, you must order the 1756-BA1 battery separately for memory backup. No programming cable (1756-CP3) is provided.

Frequently Asked Questions (FAQ)

1. Does the 1756-L1M1 have nonvolatile memory?
No. The Allen-Bradley 1756-L1M1 does not include nonvolatile memory. Therefore, you must use a 1756-BA1 battery to retain programs when removing power.

2. What memory capacities does this processor have?
The 1756-L1M1 provides 500 KB for data and logic. It also provides 150 KB for I/O memory. Expansion memory adds 512 KB.

3. What battery works with this controller?
The Allen-Bradley 1756-L1M1 uses the 1756-BA1 lithium battery. This battery weighs 0.59 grams and is the only compatible replacement.

4. What programming cable does this module require?
The 1756-L1M1 requires the 1756-CP3 serial cable. This cable must meet category 3 specifications.

5. Can I install this processor in any chassis slot?
Yes. The Allen-Bradley 1756-L1M1 works in any available ControlLogix chassis slot. There are no slot restrictions for this processor.

Why Choose the Allen-Bradley 1756-L1M1?

This ControlLogix processor delivers reliable control for small to medium applications. For starters, the Allen-Bradley 1756-L1M1 provides 500 KB of data and logic memory plus 512 KB of expansion memory. The controller weighs only 0.35 kg for easy handling. You can install the 1756-L1M1 in any available chassis slot for flexible system design. The replaceable 1756-BA1 battery retains programs during power loss. The module requires the 1756-CP3 serial cable for programming connectivity. Operating temperature ranges from 0°C to 60°C for industrial environments. The 1756-L1M1 withstands 30 G operating shock and 2.0 G vibration for rugged reliability. ESD immunity reaches 6 kV contact and 8 kV air discharge for noise resistance. Radiated RF immunity reaches 10 V/m across multiple frequency ranges. Most importantly, this processor integrates seamlessly into ControlLogix systems with standard RSLogix 5000 software.

Order the Allen-Bradley 1756-L1M1 today for your ControlLogix control needs. Specifically, this processor is perfect for machine control, material handling, packaging equipment, and other small to medium applications requiring the ControlLogix 5550 platform.