The Allen-Bradley 1791-NDV is a compact Block I/O module from Rockwell Automation, designed for efficient input and output signal management in distributed control systems. It features a total of six channels, including four input channels and two output channels, providing flexible configuration for various industrial automation applications. As part of the Allen-Bradley 1791 series, the 1791-NDV offers reliable performance, space-efficient installation, and seamless integration within modular control architectures.