The Allen-Bradley 1794-OB16D is a 1794 FLEX Digital DC Output Module. It is a Diagnostic (D) module that detects, indicates, and reports open and shorted input or output field devices or wiring. It is fitted inside the terminal bus making a connection with the field devices and the I/O bus. Modules can be inserted or removed under power since the I/O module does not have any direct wiring. It in turn saves time and removes system restarting inefficiency.

The 1794-OB16D module has 16 current sourcing outputs. It has a 24V DC nominal On-State output voltage, a 10 – 31.2V DC On-State output voltage range and 500mA per channel with 8A per module maximum On-State output current. It has a maximum output delay time of 0.1ms from On-to-Off and vice versa. It has a maximum power dissipation of 4.8W at 31.2V DC. Terminal Base units compatible with it are the 1794-TB3, 1794-TB3S and the 1794-TBKD. It has an external power supply of 10 - 31.2V DC voltage with 5% AC ripple and 56 - 78mA current. It is installed using a DIN rail by simply snapping it onto the DIN rail. It has various communication options like ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O.

The 1794-OB16D module has 16 yellow LED status indicators for each channel indicating the corresponding input device and output signal. It also has XT versions of standard modules for operating in extreme environments, reducing panel and maintenance costs. It has a 0 - 55 °C (32 - 131 °F) operating temperature and 5 - 95% noncondensing relative humidity.