The 1791-24A8 is a Discrete AC Block I/O Module with 24 output points and 8 input points. It is manufactured by Allen Bradley/Rockwell Automation as part of the 1791 Block I/O product line. This module comes with three groups of 8, while the input is in 1 group of 8. It features an input impedance of 15 kilo-ohms at 60 hertz and a nominal input current of 11 milliamps. The module operates on an input voltage of 120 volts AC. This module remains on standby mode when it is powered ON with an input voltage of 79 – 132 volts at a 47 - 63 Hertz frequency range. It comes with an output voltage range of 20 – 132 volts AC. This module is designed and intended for safe and easy to use, and it has a variety of inbuilt safety, including isolation and internal protection mechanism. Allen Bradley 1791-24A8 AC Block, I/O Module, comes with three isolations, including isolation between I/O group to group, I/O group to logic, and power supply to RIO. The isolations can tolerate a voltage of up to 1250 volts AC and 500 volts AC. The internal protection mechanism offers protection against damages that may be caused by excessive current. Therefore, there is no need to install external protection for the module, for instance, fuse. The module also features an internal protection mechanism that can protect it up to 13.5 times against the nominal input current of 150 milliamps. It also features a programmable controller interface that makes the module easy to operate and navigate.

The Allen Bradley 1791-24A8 discrete AC block I/O module has a maximum off-state voltage rating of 35 volts. The minimum on-state current of this device is 5 milliamperes at 79 volts at 60 hertz, while the maximum on-state current is 12.3 milliamperes at 132 volts at 60 hertz. Additionally, the 1791-24A8 has a minimum off-state current rating 2.3 milliamperes at a frequency of 60 hertz. The maximum input impedance of this module is rated at 15 kilo ohms at a frequency of 60 hertz. The input signal delay from off to on is 1.0 millisecond. Additionally, the input signal delay from on to off is 26 milliseconds maximum and allows for a 1/2 cycle drop-out. The Allen Bradley 1791-24A8 discrete AC block I/O module has different output current rating s depending on its mounting orientation. When mounted vertically, this product has an output current rating of 300 milliamperes at 60 degrees Celsius and 600 milliamperes at 30 degrees Celsius. When mounted horizontally, however, the output current rating is 150 milliamperes at 60 degrees Celsius and 300 milliamperes at 30 degrees Celsius. The minimum on-state current of this product's outputs is 50 milliamperes per output. Additionally, the maximum on-state voltage drop is 1.5 volts peak at 300 milliamperes. Furthermore, the maximum off-state leakage current is 3 milliamperes. The output signal delay for off to on is1 millisecond at 60 hertz and 1 millisecond at 50 hertz, while from on to off, the output signal delay is 8.3 milliseconds at 60 hertz and 10.0 milliseconds at 50 hertz.