ArduPlane3.4.0 ppm frames

Hello, installed qczek lrs ppm output system on apm ArduCopter 3.2.1 and channels has no reaction, but with ArduPlane 3.4.0 works fine. What is the difference between ArduCopter and ArduPlane ppm decoders, what is the required ArduCopter ppm sync time, low pulse, frame lenght, or what the problem is ?