The 1756-L71 ControlLogix 5570 Processor Module from Rockwell Automation represents the modern foundation of mid-range high-performance PLC control within the ControlLogix platform.
Built for demanding industrial automation environments, the L71 delivers fast execution speed, strong memory efficiency, and seamless integration with EtherNet/IP-based architectures. It is widely deployed in manufacturing plants, process industries, and infrastructure systems where dependable real-time control and scalable architecture are essential.
Compared to earlier L6x generations, the L71 introduces improved processing performance and tighter system integration, making it a preferred upgrade path for legacy ControlLogix installations.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1756-L71 |
| Series | ControlLogix 5570 |
| Processor Type | PLC / PAC Controller |
| User Memory | 2 MB |
| I/O Memory | ~0.98 MB |
| Nonvolatile Memory | 1784-CF128 CompactFlash (optional) |
| Serial Port | RS-232 (DF1, ASCII, DH-485) |
| Maximum I/O Capacity | Up to 128,000 digital / 4,000 analog |
| Controller Tasks | Up to 32 tasks |
| Programs per Task | Up to 100 programs |
| Backplane Current (5.1V DC) | ~1.2 A |
| Backplane Current (24V DC) | ~14 mA |
| Power Dissipation | ~3.5 W |
| Programming Software | RSLogix 5000 / Studio 5000 |
| Battery | 1756-BA1 / 1756-BATM |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Humidity | 5%–95% non-condensing |
| Dimensions (H × W × D) | 13.3 × 5.1 × 14.5 cm |
| Weight | ~0.32–0.40 kg |
The module maintains the classic single-slot ControlLogix chassis footprint, ensuring backward compatibility with existing system hardware while enabling modern control performance.
Recommended Related Models
For system expansion, upgrade, or mixed-architecture deployments, the following modules are commonly paired with the 1756-L71:
- 1756-L72 / L73 ControlLogix 5570 CPUs (higher performance variants)
- 1756-EN2T EtherNet/IP communication module
- 1756-ENBT Ethernet bridge module
- 1756-CNB ControlNet bridge module
- 1756-IB16 / 1756-OB16 digital I/O modules
Popular Allen-Bradley ControlLogix Models
Within the same platform ecosystem, widely deployed controllers include:
- 1756-L61 / L62 legacy mid-generation CPUs
- 1756-L63 / L64 high-memory ControlLogix 5560 controllers
- 1756-L71 / L72 / L73 modern ControlLogix 5570 processors
- 1756-L7SP safety partner modules (GuardLogix systems)
- 1756-EN2T high-speed Ethernet communication modules
These models form a scalable automation ecosystem supporting both legacy migration and modern IIoT-ready architectures.
