Manufacturer: Rockwell Automation
Brand: Alan Bradley
Detachable terminal: 1756-TBCH; 1756-TBS6H series
Housing type Grade: None (open)
Output signal delay: ON to OFF maximum 5 ms
Output signal delay: OFF to ON maximum 1 ms
The Allen-Bradley 1756-OB8EI is a discrete output module in the ControlLogix product family. The module has eight (8) electronically fused and independently isolated output channels capable of providing 24VDC nominal voltage output in the output voltage range of 10-30VDC. The module is generally used to energize electrical loads such as relay coils, indicator lights, buzzers, horns, alarms, valves and other drive devices.
The 1756-OB8EI is installed directly into the available slots in the 1756 ControlLogix chassis. It occupies a single slot and allows multiple instances of the same module, either locally or on a distributed I/O rack. It consumes 250 mA of backplane current at 5.1VDC and 2 mA of backplane current at 24VDC for a total backplane power of 1.30 W. The module has a power consumption of 60 W when operating at 4.7 degrees Celsius.
The 1756-OB8EI has an output current rating of 2 A@ 60 °C (140 °F) per point, while the total current per module is 10 A@ 60 °C (140 °F) and 16 A@ 55 °C (131 °F), linearly derated. It has A surge current rating of 4 A, 10 ms at a time, repeated every 2 seconds. The 1756-OB8EI has a maximum OFF to ON delay time of 1 ms and a maximum ON to OFF delay time of 5 ms.
The 1756-OB8EI is used with a detachable terminal (RTB) where the signal cable is terminated. Compatible terminals are 1756-TBCH and 1756-TBS6H.
The module operates at 10-30V DC and the voltage class is 12-24V DC in/out. It has A short stroke greater than 4.5 A, a maximum of 500 μs (output turned on, then short-circuited), a maximum of 4.5 A greater than 1.5 ms (output turned on and short-circuited), and a diagnostic time stamp of +/ -1 ms. It has a current consumption of 250 mA at 5.1V and 2 mA at 24V. The backplane of the module has a total power of 1.30 W and a maximum heat dissipation of 16.03 BTU/ hour. The module has A maximum turn-off leakage current of 1 mA per point and a maximum voltage drop of 1.2V DC (2 A). At 60 degrees Celsius, the maximum current per point is 2A, and the maximum current per module is 10A at 60 degrees Celsius and 16A at 55 degrees Celsius (linear derating).
It has A surge current of 4 A per point for 10 ms, which can be repeated every 2 seconds, and a minimum load current of 3 mA. It also has a continuous isolation voltage of 250V, and the module undergoes a routine test at 1350V for 2 seconds. 1756-OB8EI allows you to choose to remain in the last state and turn the state on or off in fault mode or program mode. Note that the default setting for both is "Off." It also has a maximum output delay time of 1 m from off to on and a maximum output delay time of 5 ms from on to off. Its operating temperature range is 0-60 degrees Celsius, and its non-operating temperature range is -40-85 degrees Celsius. It has a maximum ambient air temperature of 60 degrees Celsius and a non-condensing relative humidity level of 5-95%.
