Allen Bradley 1771-OBD

Product Features

Allen Bradley 1771-OBD provides 16 non-isolated output channels that support sinking current configuration (the output device draws current from the module).

The green “module active” indicator lights up when the module is powered on and the processor is in RUN mode, and turns off when the processor resets the output. The red “fuse blown” indicator lights up when the built-in fuse in the module blows.

Allen Bradley 1771-OBD has 16 red “output status” indicator lights, displaying the transistor state of the processor's instructions (independent of the actual voltage at the output terminals).

Allen Bradley 1771-OBD is equipped with a 10A/250V rectifier fuse (Littelfuse 322010) that provides protection for the module in case of output overload (exceeding 10A) or short circuit (does not protect individual output transistors).

Allen Bradley 1771-OBD is resistant to static discharge and complies with the IEC 61000-4-2 standard, supporting 4kV indirect contact discharge. It is electromagnetic compatibility (EMC) compliant with CISPR 11 Group 1, Class A (requires a suitable enclosure), and is suitable for industrial environments with electromagnetic interference.

Allen Bradley 1771-OBD can be wired using field wiring terminals (e.g., 1771-WH) and supports module hot-swapping (requires power-off operation).

Product Working Principle

Allen Bradley 1771-OBD must be installed in the 1771 series I/O chassis (except for the leftmost slot, which is reserved for the processor or adapter) and correctly inserted using the key configuration (between 10-12 and 22-24).

Field devices are connected via the 1771-WH (or the fused 1771-WHF/1771-WHFB) wiring arm. Note the DC power polarity (reverse connection or AC connection will damage the module), and all DC connection terminals (A-D) must be shorted to prevent overload.

Allen Bradley 1771-OBD receives processor instructions via the chassis backplane to control the on/off status of 16 output channels. LED indicator lights provide real-time feedback on instruction status. The fuse will blow when the total output current exceeds 10A, power must be disconnected before replacement.  

Product Parameter

The following detail is for Allen Bradley 1771-OBD DC Output Module.

Number of outputs: 16 non-isolated outputs

User supply voltage: 10-60V DC (nominal 48V DC)

Current rating:

Resistive load: 2A per output, total module current ≤8A

Pilot duty load: 0.2A per output

Maximum surge current: 4A per output for 10ms, repeatable every 2s, 25A per output for 10ms, repeatable every 2s

Minimum load current: 2.5mA

On-state voltage drop (at rated current): ≤1.5V DC

Off-state leakage current: ≤0.5mA

Signal delay: Off to on ≤0.1ms, On to off ≤0.2ms

Backplane power supply: 5V DC, maximum 400mA (must be included in chassis total power consumption calculation)

Isolation voltage: 60V DC (continuous), 1000V AC (1-minute test, I/O to system)

Conductor wire size: 0.34-2.5mm² (22-14 AWG) solid or stranded copper wire, insulation max 1.2mm

Field wiring arm screw torque: 1.0 Nm (9 lb-in)

Keying: Backplane connector keying between 10 and 12, and between 22 and 24

Operating temperature: 0-60°C (32-140°F)

Storage temperature: -40-85°C (-40-185°F)

Relative humidity: 5-95% non-condensing

Vibration: 2g at 10-500Hz (IEC 60068-2-6)

Shock (operating / non-operating): 30g / 50g (IEC 60068-2-27)