Allen-Bradley 1738-OB8EM12 ArmorPoint Digital Output Module

The Allen-Bradley 1738-OB8EM12, also cataloged as the 1738-OB8E Digital Output Module, operates as a dedicated hardware component for discrete load switching and actuator control within Allen-Bradley ArmorPoint systems.

Hardware Specifications

Deterministic Ethernet/IP Networks and I/O Density Scaling

• EtherNet/IP Deterministic Networks: Receives discrete control commands from fieldbus adapters over the local PointBus backplane, executing output logic states without network transmission latency.
• I/O Density Scaling: Integrates 8 electronically protected sourcing output channels into an IP 65/66/67 machine-mount form factor using M12 micro connections, maximizing local point density in washdown control applications.
• Firmware Flash Compatibility: Maintains synchronized execution profiles and real-time operational feedback via LED indicators for output status, module health, and network connectivity.

Frequently Asked Questions

Q: What is the maximum load current capacity supported per channel on the 1738-OB8EM12? A: The module supports up to 1.0 A maximum on-state output current per individual channel across an operating voltage range of 10 to 28.8 VDC.

Q: What PointBus backplane power current is consumed by the 1738-OB8EM12 module? A: The internal logic circuits draw a maximum of 75 mA at 5 VDC from the PointBus power rail.

Q: What visual diagnostics are provided directly on the 1738-OB8EM12 physical enclosure? A: The front panel includes yellow/red output status LEDs for channel state and fault detection, alongside green/red status LEDs for module and network link condition.

Field Installation Guidelines

• Mount the sealed module housing directly to equipment framework using appropriate mechanical fasteners, ensuring flat surface contact to preserve IP 65/66/67 ingress sealing.
• Connect actuator lines via M12 micro cable assemblies. Hand-tighten coupling rings to standard torque limits to ensure water and dust exclusion.
• Separate 24 VDC output load cabling from heavy AC electrical lines to reduce inductive coupling and transient noise.
• Confirm total field supply voltage remains within the 10 to 28.8 VDC operating range prior to energizing output load circuits.