Allen-Bradley 1746-OV16 SLC 500 Discrete Output Module

The Allen-Bradley 1746-OV16, also cataloged as the 1746-OV16 discrete output module, operates as a sinking-type digital actuator interface for 10-50 VDC load switching within SLC 500 backplane-based control systems. The Allen-Bradley 1746-OV16 (1746-OV16 output module) provides direct electrical switching of 16 independent output channels through scan-synchronized backplane execution in SLC 500 rack architectures.

The module converts controller output states into field-level sinking signals with a nominal 24 VDC supply domain. Each channel supports controlled current delivery with defined thermal derating across operating temperature ranges, while all outputs are grouped into a single 16-point channel bank.

Hardware Specifications

SLC 500 Backplane Scan Execution and Sinking Output Behavior

The 1746-OV16 executes output state transitions through deterministic SLC 500 backplane scan cycles, where output image register values are latched at the end of each processor scan. Each of the 16 sinking channels operates as a low-side switching element, providing current path completion for externally supplied 10-50 VDC loads.

Backplane current consumption is fixed at 0.270 A on the 5 VDC logic rail, decoupling control logic from field power domains. Output switching timing is defined by sub-millisecond ON response (0.1 ms) and OFF transition latency of 1.0 ms, enabling high-speed discrete actuation for tightly synchronized I/O sequences.

Thermal derating reduces per-point current capacity from 0.50 A at 30 deg C to 0.25 A at 60 deg C, enforcing load distribution constraints across high-density switching operations.

Frequently Asked Questions (FAQ)

Q: Does the 1746-OV16 support hot-swap insertion in an energized SLC 500 rack?
A: No. Module insertion or removal requires chassis power removal to prevent backplane signal disturbance.

Q: How is output current distributed across the module?
A: The module supports 0.50 A per channel at 30 deg C, with a total module limit of 8 A under the same thermal condition.

Q: What determines output switching delay behavior?
A: Switching latency is defined by internal solid-state switching elements and SLC 500 backplane scan synchronization, with ON at 0.1 ms and OFF at 1.0 ms maximum.

Field Installation Guidelines

Install the 1746-OV16 into a compatible SLC 500 chassis slot with correct alignment to the backplane connector. Ensure chassis power is fully isolated before insertion or removal.

Field wiring shall follow sinking configuration rules, where external loads are connected to positive supply and module channels complete the return path. Maintain correct polarity to avoid unintended current paths.

Signal cables should be routed separately from high-voltage or high-frequency conductors to reduce inductive coupling. Shield termination should be grounded at a single control cabinet reference point. Verify backplane seating before energizing the system.