1771-OBD/C Allen-Bradley Discrete output module

The Allen-Bradley 1771-OBD is a Sixteen (16) channel, non-isolated output module that is part of the 1771 Product bulletin. This module is especially compatible for use with the PLC5 product family, typically used for energizing DC powered electrical loads such as pilot lamps, relay coils, solenoid actuated devices and other devices. It has an output voltage range of 10-60 VDC with nominal voltage output of 48 VDC.

The 1771-OBD’s output channels are rated 2 A, resistive, not-exceeding 8 A per module and 0.2 A per pilot duty output. Each channel has minimum Surge current rating of 4 A per output for 10 ms, repeatable every 2 s and maximum of 25 A per output for 10 ms, repeatable every 2 s while the module’s minimum load current is 2.5 mA.

The 1771-OBD’s On-state voltage drop is 1.5V dc; maximum Off-state leakage current of 0.5 mA; Output signal delay of 0.1 ms for Off to On transition and 0.2 ms for On to Off transition. It is mounted to any of the 1771-A1B through 1771-A4B I/O chassis except the 1771-A4 I/O chassis. It is compatible for use with the 1771-WH, 1771-WHF and 1771-WHFB Field Wiring Arms with tightening force requirement of 1.0 Nm (9 lb-in) and module keying of between 10 and 12 / 22 and 24. Appropriate signal wires for termination of output devices to each of the module’s channel ranges from 0.34-2.5 mm2 (22…14 AWG) solid or stranded copper wire with insulation rating of 120 °C (248 °F) or greater and maximum insulation thickness of 1.2 mm (3/64 in.).

It has a maximum surge current of 4 Amps per output for 10 milliseconds, which is repeatable every 2 seconds. The 1771-OBD module has a minimal load current of 2.5 mA, and its maximum on-state voltage drop is 1.5 Volts DC while its maximum off-state leakage current is .5 mA. The maximum power dissipation of the 1771-OBD module is 15.6 W, its maximum thermal dissipation is 53.3 BTU/hour, and its maximum backplane current is 400 mA at 5 Volts DC. Connecting or disconnecting a cable without first cutting off the power from the sides of the field can cause an electrical arc. With an operating temperature range of 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit), a storage temperature range of -40 to 85 degrees Celsius (-40 to 185 degrees Fahrenheit), and a relative humidity range of 5 to 95% (without condensation), this module is a durable device that can withstand many different conditions. The 1771-OBD has an operating shock of 30 G (3-pulse at 11 milliseconds) and a nonoperating shock of 50 G (3-pulse at 11 milliseconds). Additionally, the 1771-OBD has an ESD immunity of 4 kV contact discharges and 8 kV air discharges.