Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1734-OB8S |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Product Type | Safety Sourcing Output Module |
| Series | POINT Guard I/O (1734) |
| Output Channels | 8 (sourcing) |
| Operating Voltage | 24 VDC nominal (19.2…28.8 VDC range) |
| Output Current per Channel | 1 A max @ 40°C; 500 mA max @ 55°C |
| Output Current per Module | 8 A max @ 40°C; 2 A max @ 55°C |
| Output Type | Solid-state, current sourcing |
| Operational Modes | Single-channel and dual-channel |
| Safety Certification | TÜV: SIL CL 3 (IEC 61508), PLe / Cat. 4 (ISO 13849-1) |
| Communication Protocol | CIP Safety over EtherNet/IP or DeviceNet |
| Backplane Current | 125 mA at 5 VDC |
| Field Power Current | 50 mA (no load) |
| Isolation Voltage | 50 V continuous (field to system, basic insulation) |
| Protection Features | Electronic short-circuit protection |
| Dimensions (W×H×D) | 25 × 77 × 55 mm |
| Weight | Approximately 0.26 kg |
| Operating Temperature | -20°C to +55°C |
Main Features and Advantages
Certified Functional Safety: The Allen-Bradley 1734-OB8S carries TÜV Rheinland certification for SIL CL 3 according to IEC 61508 and PLe/Category 4 according to EN ISO 13849-1, making it suitable for the most demanding functional safety applications . This certification provides documented evidence of the module‘s reliability and failure rates, simplifying safety validation for machine builders and system integrators.
Flexible Operational Modes: The Allen-Bradley 1734-OB8S supports both single-channel and dual-channel configurations. In dual-channel mode with safety pulse testing enabled, the module achieves PLe/Cat. 4/SIL CL3 ratings, enabling redundant control of safety actuators for maximum risk reduction. Single-channel mode provides PLd/Cat. 2/SIL CL2 capability for applications with lower risk profiles, offering cost-effective safety compliance .
Comprehensive Diagnostics: Each output channel on the Allen-Bradley 1734-OB8S includes pulse-test capability for detecting field wiring short circuits to positive or negative supply rails. When the module detects a fault, outputs are de-energized and remain in a safe state until the fault condition is cleared . This diagnostic coverage is essential for maintaining high Performance Level ratings in safety functions.
Compact POINT I/O Integration: The Allen-Bradley 1734-OB8S occupies a single slot in any standard POINT I/O chassis, sharing the same terminal bases and mounting infrastructure as non-safety modules. This density and compatibility reduce panel space requirements and simplify system architecture compared to proprietary safety I/O platforms.
Robust Output Protection: Electronic short-circuit protection on the Allen-Bradley 1734-OB8S prevents damage from field wiring faults and ensures reliable operation in industrial environments where wiring errors or insulation failures may occur . The module’s solid-state output design eliminates contact wear and provides consistent switching performance over millions of operations.
