Allen Bradley 1734-OB8S POINT Guard I/O Safety Output Module

Configured for safety-rated output control in POINT I/O networks, the Allen Bradley 1734-OB8S (1734-OB8S) Safety Output Module provides direct physical/electrical execution of safety-critical load switching within industrial automation platforms.

Hardware Specifications

Safety Integrity and Fail-Safe State Execution

The 1734-OB8S is engineered to meet rigorous SIL3 safety certification standards for machine and process control. The module utilizes a safety-rated architecture to execute fail-safe state transitions in response to diagnostic faults or loss of controller communication. Internal circuitry provides galvanic isolation between the field power domain and backplane logic, ensuring that external electrical disturbances do not compromise safety-critical switching performance. The module supports both single-channel and dual-channel operational modes, allowing for versatile safety-rated load control while maintaining continuous diagnostic coverage of output integrity.

Frequently Asked Questions

Q: Does the 1734-OB8S support hot-swapping under power?

A: No. Due to the safety-critical nature of this hardware, hot-swapping is prohibited. The field power and backplane power must be de-energized before removing or installing the module to prevent electrical faults.

Q: How does ambient temperature affect the current capacity of the module?

A: The maximum output current is thermally derated based on the operating environment. At 40 deg C, the module supports a maximum of 8 A, while at 55 deg C, the maximum capacity is reduced to 2 A to prevent thermal degradation of the internal components.

Field Installation Guidelines

1. Mount the module on the designated 1734 POINT I/O base assembly, ensuring the mechanical locking latch is fully engaged.
2. Verify that the field power supply is within the 19.2 to 28.8 VDC range prior to connection to avoid undervoltage or overvoltage trip conditions.
3. Terminate output wiring according to the intended operating mode (single-channel or dual-channel) as defined by the application safety logic.
4. Ensure adequate spacing around the module to facilitate airflow, particularly when operating near the 55 deg C ambient temperature limit.
5. Use shielded cabling for field output runs to mitigate electromagnetic interference and maintain electrical signal integrity.
6. Perform a comprehensive safety validation test upon initial power-up to confirm that all outputs transition to the defined safe state upon command or fault detection.