The Allen-Bradley 1756-L72 serves as a core processing engine within the high-performance ControlLogix 5570 programmable automation controller (PAC) ecosystem. This hardware platform coordinates extensive multi-axis motion loops, dense discrete sequencing, and specialized process instrumentation tasks. It runs complex applications using 4 MB of dedicated user memory alongside 0.98 MB of separate backplane I/O memory allocation. The unit slides into any standard ControlLogix chassis to establish instant high-speed data exchanges with adjacent network communication modules and local I/O cards. We supply this product as a 100% Brand New, original factory-sealed unit, which guarantees fresh internal energy storage components and authentic manufacturer firmware compliance for critical factory control panels.
| Parameter | Specification Value |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Product Line | ControlLogix 5570 Series |
| Model Number | 1756-L72 |
| Product Type | Standard Programmable Automation Controller |
| User Memory Capacity | 4 Megabytes (4 MB) |
| I/O Memory Capacity | 0.98 Megabytes (0.98 MB) |
| Maximum Controller Tasks | 32 Tasks Maximum |
| Program Capacity per Task | 100 Programs per Task |
| Maximum Backplane Connections | 500 Controller Connections |
| Integrated Communication Ports | 1 x USB 2.0 Programming Port |
| Network Protocol Modules | EtherNet/IP, ControlNet, DeviceNet, DH+, Remote I/O, SynchLink |
| Controller Redundancy | Fully Supported via 1756-RM redundant modules |
| Non-Volatile Storage Slot | Supports optional 1784-SD1 or 1784-SD2 Secure Digital cards |
| Current Draw from Backplane | 1.2 Amps at 5.1V DC, 5.0 milliamps at 1.2V DC |
| Power Dissipation Profile | 2.5 Watts total |
| Thermal Dissipation Level | 8.5 BTU per hour |
| Chassis Compatibility Matrix | Standard 1756 ControlLogix chassis (all slot sizes) |
| Operating Temperature Range | 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit) |
| Storage Temperature Range | -40 to 85 degrees Celsius (-40 to 185 degrees Fahrenheit) |
| Physical Net Weight | 0.56 lbs (0.26 kg) |
| Agency Compliance Standards | UL, CE, CSA, ATEX, IECEx |
Accelerate Process Scan Cycles: The 1756-L72 utilizes a high-velocity processing core to compute massive lines of ladder logic, structured text, and function blocks concurrently. This processing velocity handles up to 32 parallel tasks with 100 programs each, dropping cycle times significantly across complex high-speed assembly and synchronized sorting lines.
Consolidate Plant-Wide Net Communications: This controller acts as a central data bridge by executing multi-protocol logic simultaneously. It manages up to 500 independent data connections across modern EtherNet/IP rings while maintaining legacy connectivity down to existing ControlNet, DeviceNet, or Data Highway Plus (DH+) remote I/O nodes.
Deploy Seamless Hot-Standby Redundancy: Two identical 1756-L72 modules link together through 1756-RM redundant hardware modules to create an active/standby partnership. The backup controller mirrors all program steps and active state registers continuously, completing a bumpless switchover during primary unit faults to maintain process continuity in continuous manufacturing environments.
Eliminate Maintenance Battery Maintenance: An integrated electrochemical capacitor energy storage module provides temporary backup voltage to flush internal RAM files directly onto the non-volatile Secure Digital (SD) card during a plant blackout. This design eliminates the regular replacement costs and toxic waste profiles of traditional lithium battery cells.
Integrate Machinery Safety Frameworks: While functioning as a high-density standard control CPU, the 1756-L72 seamlessly coexists with GuardLogix safety coprocessors inside the same chassis. This co-processing ability shares data backplane resources directly, lowering overall hardware acquisition costs in hazardous processing zones.
Does the 1756-L72 package include the 1784-SD1 Secure Digital card as standard?
Yes. Allen-Bradley ships each 1756-L72 controller with a pre-installed 1784-SD1 Secure Digital memory card inside the card slot. If your application requires larger storage capacities for extensive recipe management or internal data-logging arrays, you can field-upgrade the storage to a 1784-SD2 card.
What software version do I need to program the 1756-L72 module?
Programming the 1756-L72 requires Studio 5000 Logix Designer or RSLogix 5000 software, depending on the firmware revision level loaded onto the unit. The 5570 controller line generally utilizes firmware version 20 or higher to leverage its advanced memory structure and integrated motion control profiles.
How does this controller handle internal data protection during power failure?
The controller contains an on-board energy storage module (ESM) that maintains electrical current for several seconds following a main power loss. The CPU uses this reserve energy to copy the volatile user program data into the non-volatile SD flash memory card automatically, preserving your latest logic registers indefinitely without battery maintenance.
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