Relay uses your (internal or external) sound card as a relay detector, and translates on/off signals into RDS commands that can be sent to most RDS encoders, including those in Stereo Tool and STXtreme.

For now we only support sending PI codes, but just ask us when you need more and we'll add fields where you can enter lists of RDS commands. This is a niche product so we only add features to it when people ask for them - and unless you have very specific requests that won't cost extra.