The Keysight Y1731A is a PXI I/O adapter module equipped with twelve SMB connectors that provides access to control signals from vector network analyzers (VNAs) such as the PXI M980xA and M983xA models and the Streamline P50xxA/B and P93xxB series. This module is essential for synchronized measurements with external devices such as pulse generators, modulators or RF switches and supports hardware triggering as well as communication between the VNA and digital or analog I/O modules such as the M9341A/B. It significantly extends the functionality of the VNAs and is particularly useful for applications that require precise timing and control signals.