The Keysight N1294A-031 GPIO-BNC trigger adapter makes it easy to send and receive trigger signals between B2900A Series products and other instruments with BNC triggering connections (such as nano-volt meters and network analyzers).
The adapter also permits you to add additional connections to the digital I/O output. Simply open up the adapter, solder a wire to the adapter’s internal printed circuit board, and route it out through the hole on the adapter.