The 1756-L71S GuardLogix 5570 Safety Processor Module from Rockwell Automation is an integrated safety PLC designed for industrial systems that require standard control logic and functional safety (SIL-rated control) in a single controller architecture.
Unlike the standard 1756-L71, the L71S belongs to the GuardLogix safety platform, meaning it is built for applications where machine safety, emergency shutdown logic, and protected control execution must coexist in one unified control system. It is widely used in automotive, robotics, packaging, and process safety environments where compliance and reliability are critical.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1756-L71S |
| Series | ControlLogix / GuardLogix 5570 |
| Processor Type | Safety + Standard Integrated CPU |
| Standard User Memory | 2 MB |
| Safety Memory | 1 MB |
| Nonvolatile Memory | 1 GB (typical shipped SD/CF configuration) |
| Motion Support | Up to 100 axes |
| Maximum I/O Capacity | Up to 128,000 points |
| Safety Rating | SIL 3 / PLe system capability |
| Controller Tasks | Up to 31 standard + 1 safety task |
| Communication | Via 1756 modules (EtherNet/IP, ControlNet, DeviceNet) |
| Built-in Port | 1 × USB programming port |
| Redundancy Support | Not supported |
| Backplane Current (5.1V DC) | ~0.8 A |
| Power Dissipation | ~2.5–3 W |
| Programming Software | RSLogix 5000 / Studio 5000 GuardLogix |
| Battery | 1756-ESMCAP / internal energy storage module |
| 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 | ~0.26 kg |
The L71S uses the standard ControlLogix single-slot chassis format, making it fully compatible with existing ControlLogix racks while adding integrated safety functionality.
Recommended Related Models
For system design, safety expansion, or modernization, the L71S is commonly paired with:
- 1756-L72S / L73S GuardLogix CPUs (higher performance safety controllers)
- 1756-EN2T EtherNet/IP communication module
- 1756-ENBT Ethernet bridge module
- 1756-L7SP safety partner module (for certain configurations)
- 1756-IB16 / OB16 digital I/O modules
- 1756-RM redundancy module (system-dependent architectures)
Popular Allen-Bradley ControlLogix & GuardLogix Models
Within the same ecosystem, widely used controllers include:
- 1756-L71 standard ControlLogix CPU
- 1756-L72 / L73 high-performance controllers
- 1756-L71S GuardLogix safety CPU
- 1756-L72S / L73S advanced safety controllers
- 1756-EN2T Ethernet communication modules
These models form the backbone of modern integrated safety automation systems, combining control and protection in one scalable platform.
