The method you use for PTT is dependent upon which type of sound card interface you use, as well
as which software you use.
The two methods I have used are PTT over CAT and VOX.
If you are using a SignaLink, then you should use VOX. In that case, make sure that both RRC's have
RTP tx mode set to continuous.
If you are using another type of interface, most likely you can toggle PTT using CAT commands in your software.
73,
Mitch DJ0QN / K7DX