Overview
The Allen-Bradley 1756-LSP is a GuardLogix safety partner module that functions as a dedicated co-processor for safety-related applications. This module pairs with primary GuardLogix controllers (1756-L61S, 1756-L62S, or 1756-L63S) to create a redundant, isolated safety channel rated up to Safety Integrity Level (SIL) 3 and Performance Level (PL) e. Unlike competitor solutions requiring separate safety controllers, the 1756-LSP integrates into the ControlLogix chassis for streamlined safety compliance.
Key Features
- Co-processor architecture provides isolated redundant safety processing
- No user memory for standard tasks; safety memory corresponds to primary controller (1 MB with L61S/L62S, 3.75 MB with L63S)
- 250 maximum controller connections
- CompactFlash nonvolatile memory card support
- Built-in RS-232 serial port for diagnostics and commissioning
- LED status indicators for operational and fault monitoring
Technical Specifications
The 1756-LSP draws power from the ControlLogix backplane with minimal electrical footprint. Current consumption is 1200 mA at 5.1 V DC and 14 mA at 24 V DC, with a power dissipation of 3.5 W and thermal dissipation of 11.9 BTU/hr. The module features 30 V continuous isolation voltage (basic insulation), type-tested from RS-232 port-to-system at 720 V DC for 60 seconds.
Environmental ratings include an operating temperature range of 0–60 °C and non-operating range of −40–85 °C, with maximum ambient temperature of 60 °C and non-condensing relative humidity of 5–95%. Operating shock tolerance is 30 g; non-operating shock is 50 g. Operating vibration is rated at 2 g across 10–500 Hz frequency range.
Typical Applications
- Machine guarding and emergency stop logic in manufacturing environments
- Process safety interlocks requiring SIL 3 certification
- Redundant control channels in critical automation systems
- Functional safety compliance in food, pharmaceutical, and chemical processing
- Heavy equipment safety systems in automotive and metals fabrication
Compatibility & Replacements
The 1756-LSP is designed exclusively for the ControlLogix 5560 GuardLogix family and pairs with primary controllers 1756-L61S, 1756-L62S, and 1756-L63S. Installation must be in the slot immediately to the right of the primary controller to meet SIL 3 architectural requirements. The partner module occupies one physical slot but the pair uses two consecutive chassis slots. For L7-series GuardLogix controllers, use the 1756-L7SP instead. The module ships with integrated battery backup and requires CompactFlash memory cards for program storage.
