Allen-Bradley 1756-OB8I Isolated DC Output Module

The Allen-Bradley 1756-OB8I is an eight-point isolated DC output module designed for ControlLogix I/O backplanes, delivering eight independently isolated 10–30 V DC outputs capable of up to 2 A per point. Each output is isolated from the backplane and from other channels, enabling loads to be driven without backplane ground loops; the module supports a total load of up to 16 A across all points. Operating voltage range is 10–30 V DC, with 12/24 V DC sources supported. Response times: Off-to-On in up to 1 ms; On-to-Off in up to 2 ms. Electrical characteristics include 0.5 mA maximum leakage current in the off state per point, and a maximum on-state voltage drop of 0.5 V at 2 A. Surge capability allows up to 4 A per point for 10 ms, repeatable every 1 s, at up to 60 °C. Total backplane current is limited to 16 A; total backplane power 0.89 W, with a module power dissipation up to 4.6 W at 60 °C. The module uses removable terminal blocks for wiring, and is suitable for driving DC loads such as relays, solenoids, and indicators in Rockwell Automation 1756 systems.