Manufacturer: Rockwell Automation
Brand: Alan Bradley
Part Number/Catalog number: 1756-OB8I
Series: ControlLogix
Module type: heterogeneous DC output module
Output: 8 isolated
Voltage: 12-24 volts DC
Operating voltage range: 10-30 volts DC
The Allen-Bradley 1756-OB8I is a ControlLogix DC isolated output module. It has eight independently isolated outputs and provides lead values. The module has not been fused, and to help protect the output, a fused IFM is recommended.
Before installing the 1756-OB8I module in a compatible chassis, a 36-pin detachable terminal housing (RTB) is required. For this module, you can only use the 1756-TBCH or 1756-TBS6H RTB. Remember to ground and install the chassis before installing the module using RTB.
Communication formats available for the 1756-OB8I module include Listen only rack optimization, listen only output data, timed output data, output data, and rack optimization. The module also has a feature that allows you to change the state of each point in fault or program mode, with the available options being "On", "Off" and "Keep Last", with "Off" set as the default.
The 1756-OB8I module is a 12/24 volt DC power supply module with an operating voltage range between 10 and 30 volts DC. The total power of the backplane is 0.89W, and the current consumption is 165 mA at 5.1 V and 2 mA at 24 V. Its surge current is 4 A per point for 10 ms and can be repeated once per second at 140 degrees Fahrenheit. It has A minimum load current of 2 mA, a maximum current of 140 degrees Fahrenheit per point, and a maximum current of 16 A, 140 degrees Fahrenheit per module. The module has A maximum on-state voltage drop of 0.5 V DC (2 A) and a maximum off state leakage current of 0.5 mA per point.
At 140 degrees Fahrenheit, it has a maximum power consumption of 4.6W and a heat dissipation of 15.70 BTU/hr. The module has been routinely tested for 2 seconds at 1350 volts AC and has a continuous isolation voltage of 250 volts.
