The 1791-8AC is a Block I/O module manufactured by Allen Bradley/Rockwell Automation as part of the 1791 Block I/O product line. This is a discrete I/O module with an inbuilt remote I/O device, as well as a power supply interface and a programmable controller. The unit is an 8-output and 8-input block module with 11.0 amperes nominal input current and 120 volts AC nominal input voltage. It has an ON-state voltage rating of 79 – 132 volts AC at a frequency of 47 - 63 hertz with an ON-state current rating of 5.0 milliamps at 79 volts and a frequency of 60 hertz. The module features a maximum OFF-state current of 2.5 milliamps, a voltage of 35 volts AC at a frequency of 60 hertz at a maximum input impedance of 15 kilo-ohms at 60 hertz. The 1791-8AC module features an input signal delay of 26 milliseconds ON to OFF and 1 millisecond OFF to ON, allowable for half cycle dropout. Allen Bradley 1791-8AC Block, I/O module, has 8 outputs with a voltage rating of 20 – 132 volts AC, and 300 - 600 milliamps of output current at 30 – 60 degrees Celsius when vertically mounted, and 150 – 300 milliamps at 30 – 60 degrees Celsius when horizontally mounted. It has a surge current of 10 amperes for 50 milliseconds recurring after every 2 seconds with 50 milliamps minimum ON-state output current per output. The 1791-8AC module has a maximum drop voltage of 1.5 volts at 300 milliamps and a current leakage at 3 milliamps in the OFF-state.

The 1791-8AC implements Distributed Input/Output solutions. This module is part of the legacy Input/Output block family and may be utilized with RIO equipped processors (i.e., SLC500) with 1747-SN and older controller platforms like as PLC5, PLC3, and PLC2. This module acts as a Rio adapter and comes with eight (8) input channels, as well as eight (8) output channels. Both channels have one hundred and twenty (120) Vac and eleven (11) mA current. The integrated RIO interface of the module enables network connectivity that is smooth. It uses the solid copper wire of 2.0 mm^2 and rated up to 3/64 inches max insulation. The module has the dimension of 6.95H X 2.7W X 3.85D inches and weighs approx. 1.18 pounds. This device has two different temperature ranges that are suitable for operation, as well as storage. The ambient temperature needed to be suitable for the device's operation ranges from zero (0) to sixty (60) degrees Celsius, or thirty-two (32) to one hundred and forty (140) degrees Fahrenheit. The temperature range suitable for this product to be stored in ranges from negative forty (-40) to positive eighty-five (85) degrees Celsius. Converted, this storage temperature range is from negative forty (-40) to positive one hundred and eighty-five (+185) degrees Fahrenheit. Additionally, the relative humidity is recommended to stay within a range of 5 to 95% non-condensing. The thermal dissipation is 43.99 BTU/hr and power dissipation of the 12.9 watts.