Product Overview
The Allen-Bradley 1756-L1M2 is a ControlLogix 5550 processor module designed for demanding industrial automation environments. This Industrial Automation Module provides 1 MB of user memory (without nonvolatile memory) and supports local and remote I/O control across DeviceNet, ControlNet, and Universal Remote I/O networks. With an open-style enclosure rating and a compact footprint, the 1756-L1M2 integrates seamlessly into existing control systems.
Key Features & Benefits
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1 MB User Memory – Ample space for control logic and data tables.
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Multi-Network Support – Communicates over DeviceNet, ControlNet, and Universal Remote I/O.
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Robust Environmental Ratings – Operates from 0 to 60 °C, with storage from -40 to 85 °C.
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High Immunity – Withstands ESD discharges up to 8 kV and conducted RF interference.
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Open Enclosure – Simplifies mounting and service access.
Technical Specifications
| Specification |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1756-L1M2 |
| Series |
ControlLogix |
| Module Type |
Processor Module |
| Expansion Memory |
1 MB |
| Enclosure |
Open |
| Isolation Voltage |
30 Volts Continuous |
| Operating Temperature |
32-140 °F (0-60 °C) |
| Minimum Operating Current |
2 mA at 10 V DC |
| Maximum Operating Current |
3.5 mA at 30 V DC |
| Maximum Input Current, Off-State |
1.5 mA |
| Power Dissipation (Max) |
4.1 Watts at 60 °C |
| Backplane Current at 5 V |
120 mA |
| Backplane Current at 24 V |
2 mA |
| Removable Terminal Blocks |
1756-TBCH, 1756-TBS6H |
| UPC |
10612598180988 |
Industry Applications
The 1756-L1M2 excels in applications requiring reliable, high-speed control across distributed I/O. Typical use cases include:
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Manufacturing Lines – Coordinating multiple workstations and conveyors via ControlNet.
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Material Handling – Managing sortation systems and automated storage with DeviceNet.
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Process Control – Supervising batch processes with Universal Remote I/O.
Installation & Setup Guidance
Mount the 1756-L1M2 in a suitable ControlLogix chassis, ensuring proper backplane seating. Use the compatible programming cables 1756-CP3 or 1747-CP3 for configuration. Always observe the isolation voltage limits (30 V continuous, 50 V for up to 60 seconds) and avoid exceeding the operating temperature range. For battery replacement, use only the 1756-BA1 lithium battery (0.59 g).
Maintenance & Reliability
Regularly inspect the module for dust accumulation and ensure ventilation paths remain clear. Verify that the backplane connections are tight and free of corrosion. The 1756-L1M2 handles vibration up to 2 G (10-500 Hz) and shock up to 30 G (11 ms), but prolonged exposure beyond these limits may reduce lifespan. Keeping the unit within the specified humidity range (5-95% non-condensing) prevents condensation-related failures.
Compatibility & Integration
This processor integrates with ControlLogix chassis and supports DeviceNet, ControlNet, and Universal Remote I/O networks. It works with the 1756-TBCH and 1756-TBS6H terminal blocks, and the 1756-CP3 and 1747-CP3 programming cables. The 1756-BA1 battery is the only approved replacement.
Selection Guide & Purchasing Advice
Before purchasing, verify that the 1756-L1M2 meets your memory and network requirements. Consider whether you need nonvolatile memory – if so, look for a different model. Check that your programming cable and terminal blocks are compatible. PLC Source PRO offers genuine Allen-Bradley 1756-L1M2 modules with verified specifications and reliable sourcing.