1791D-4B4P

The Allen-Bradley 1791D-4B4P is a 4 points DC block module I/O. The 1791D-4B4P has 4 outputs and inputs. The input characteristic of this module depends on the temperature. This module has 30 Volts DC on-state voltage at 40 C and 25 Volts DC on-state voltage at 60 C. The output characteristic of this module is not temperature dependent. The range of output voltage of this module is fixed at 10 to 30 Volts DC. All outputs of this modules current also remain fixed at 4 Amps.  The 1791D-4B4P has several features such as NEMA type 1+ inputs, hardware watchdog function, and selectable input filters. NEMA type 1+ inputs offer you more flexibility by making the module compatible with various sensors. The hardware watchdog function notifies you if the microprocessor is failing. This feature alerts you of the health of the microprocessor. You can also select filters by using selectable input filters. You can select on-to-off and off-to-on delays that are suitable for your application.  There are three ways to exchange data between the master and base module I/O: change-of-state, polled, and cyclic. The 1791D-4B4P produces and consumes 1 byte every 4 inputs and 4 outputs. There will be extra byte if the module is connected with an expansion module. There are two schemes of module expansion that possible: 20 input/4 output and 4 input/20 output. Each of these schemes will produce or consume more bits than the usual scheme.