The 7PX comes with a T-FHSS-SR receiver.Just plug on your equipment and it will work. The receiver works in normal T-FHSS mode and in the latest T-FHSS-SR
As mentioned the T stands for telemetry, no need to do anything with it but you can plug on several sensors on the SBUS connector. In SR mode the telemetry is limited.
SR is a super fast servo modus. In the transmitter the SR mode is set to "normal" with which you can use normal servo's, when you activate the SR mode (can be set for each channel sepparate) you need to have a SR mode servo/ESC connected to the SBUS oor a 800Hz-760uS servo on the channel connector.