The 1791-IOBB module is an Allen-Bradley Block I/O module. The module features 10 sinking inputs with 6 sourcing outputs. The 1791-IOBB module is a small and compact remote I/O device that comes complete with a power supply, and it has a programmable controller interface. The module features signal conditioning circuitry and it is compatible with the PLC-2, PLC-3, and the PLC-5 family programmable controllers, and the SLC 500 modular controllers by Allen-Bradley. The 1791-IOBB module features a removable remote I/O connector and an input/output connector. The removable parts aid in ensuring an easy wiring experience. The unit also features the switch assemblies. It has a built-in DIP switch for setting the I/O rack number, the starting I/O group, the unit transmission rate, the last state, and the DH-485 terminator.

To ensure ease of device monitoring and simplified troubleshooting, the 1791-IOBB module comes with LED status indicators. The LED status indicators provide a visual indication that aids the device troubleshooting. The green indicator shows whether there is communication between the processor, the scanner, and the block. The red power indicator shows if the power has been connected to the module and if the internal hardware is working. The I/O status indicators will show the state of the individual inputs and outputs. The 1791-IOBB module features the DH-485 data port that is provided for use with the SLC controller. When using the 1791-IOBB module, a termination resistor needs to be installed on the last block in the series. The ambient operating temperature range is 0 to 55 degrees Celsius, while the ambient storage temperature range is -40 to 85 degrees Celsius. The relative humidity range is 5% to 95%, non-condensing. The power dissipation is rated at 13.05 Watts maximum and 8.92 Watts under typical conditions.