The Allen-Bradley 1791D-0B8P is a DC compact block base module I/O. The 1791D-0B8P is one of 1791D series. This module has 8 outputs and no inputs. However, you can expand the number of inputs and outputs by using an expansion module. There are two expansion schemes you can use. First, the 1791D-0B8P can be expanded into 24 outputs and 0 inputs. On this scheme, the module will consume 3 output bytes and produce 1 input byte. This extra byte is returned to or shows the health of the expansion module. Second, 1791D-0B8P can be expanded into 8 output and 16 inputs. This scheme will make the module consume 3 output bytes and 1 input byte. This expansion also can make the DeviceNet current jump to 200 mA while the voltage will be around 11 to 25 Volts DC.
