Allen Bradley 1771-HS3A ControlLogix discrete output module.

The Allen-Bradley 1756-OB8 is a ControlLogix discrete output module. It features Eight (8) 24VDC output channels in Two (2) groups of Four (4) channels each. Each channel delivers an output voltage range of 10-30VDC with nominal signal voltage of 24VDC. It is compatible for use with any ControlLogix chassis and uses the 1756-TBNH and 1756-TBSH Removable Terminal Block (RTB).

The 1756-OB8 module has a voltage category of 12/24 volts DC source and an operating range of 10 to 30 volts DC. Its current draw is 165 mA at 5.1V and 2 mA at 24V. It has a backplane power of 0.89 W, with a maximum dissipation of 2.5 W at 60 Degrees Celsius (140 degrees Fahrenheit), and a thermal dissipation of 8.53 BTU/hr. The maximum off-state leakage current of this module is 1 mA per point and during an on-state, it has a maximum voltage drop of 1.2V DC at 2 A. It also has a maximum current of 2 A per point at 60 Degrees Celsius and a maximum current of 8 A at 60 Degrees Celsius per module. Its surge current per point is 4 A for 10 ms each that is repeatable every 1 s at 60 Degrees Celsius and its minimum load current is 2 mA per point. The module's isolation voltage is continuous at 250V. This module also allows you to modify states in Fault Mode per point and states in Program Mode per point. The choices for both are Hold Last State, On, or Off, with 'Off' set as default. Temperature ranges for the 1756-OB8 module are 0 to 60 Degrees Celsius when in operation and -40 to 85 Degrees Celsius when not in operation. It also has a maximum surrounding air temperature of 60 Degrees Celsius and a non-condensing relative humidity of 5% to 95%.