Pixracer V1.0 No s.bus out ?

I am in the Pixhawk + FBL system debugging, the successful application of the s.bus out connected to the FBL system, but in the use of Pixracer V1.0, you have a problem!

Will Pixracer V1.0 do not have the rssi in interface is set to s.bus out output function? In the design of Pixracer, rssi interface function and Pixhawk is a different function?