[Meseta] (AKA [UAirLtd]) came to the rescue and built [beerninja] a remote-controlled ... up a no-name USB switch, [Meseta] discovered that the switching is done with simple relays and switches.

The choice of relay was important ... The multiplexer is controlled over USB using the SCPI protocol, which happily includes an instrument class for signal switchers. We think the fit and ...