The Allen-Bradley 1771-OMD, also cataloged as the 1771-OMD Digital AC Output Module, operates as a dedicated hardware component for 220 VAC output switching and circuit protection within Allen-Bradley 1771 Universal I/O Chassis platforms.
Hardware Specifications
Parameter
Specification
Model
1771-OMD
Brand
Allen-Bradley
Origin
USA
Weight
1.69 lbs (0.77 kg)
Dimensions
Standard 1771 single-slot chassis module
Operating Temp
0 to 60 deg C (32 to 140 deg F)
Power Consumption
17.3 W maximum (3.7 W minimum)
AC Operating Voltage
184 to 250 VAC (47 to 63 Hz)
Output Channels
16 outputs
Max Continuous Current
2 A per output (8 A maximum per module)
Backplane Current
700 mA at 5 VDC
Wiring Arm
1771-WH
High-Density I/O Isolation and Backplane Determinism
The 1771-OMD module uses channel-to-backplane circuit voltage isolation to isolate field-side 220 VAC transients from controller logic, protecting internal backplane components during inductive load switching. This isolation maintains backplane bus communication velocity and supports I/O density scaling across deterministic remote I/O and ControlNet network configurations in PLC-5 control systems.
Frequently Asked Questions
Q: What is the backplane current draw for the 1771-OMD module?
A: The 1771-OMD module draws 700 mA at 5 VDC (+5%) from the 1771 chassis backplane power supply.
Q: What are the maximum continuous output current ratings per channel and per module?
A: Each individual channel supports up to 2 A continuous output current at 220 VAC, while the total aggregate current for all 16 channels on the module must not exceed 8 A.
Field Installation Guidelines
Disconnect all AC field supply voltages and chassis backplane power before inserting or removing the module from the 1771 chassis slot.
Secure the 1771-WH field wiring arm to the chassis, tightening terminal screws to a torque specification of 7 to 9 inch-pounds.
Verify that each field load meets the minimum 10 mA operating current requirement at 220 VAC to ensure proper solid-state switching latching.
Separate high-voltage AC load wiring from low-voltage communication cabling to minimize inductive noise coupling and cross-talk.
