The stage has an upgraded SPDIF chip that allows it to be connected in slave mode. This means that you can connect 2 Kempers to each other which is not possible with the head or rack.
The stage was marketed this way but after a lot of trial and error it turned out that Kemper simply had not yet activated this function in the software (without telling the buyers).
Now in 7.0.5 one month after release its ready but it doesn’t work for me. I’ve started a new thread to see if anyone can get it to work.
Why would you want to connect two Kempers using SPDIF? What are your objectives? You can just hook up two Kempers using an analog cable from direct or monitor output to your second Kemper.