I am aware of that. However, the same thing should be done in the demodulator to demodulate the signal and you can see this in amplitude demodulator technical background in the help section. But if you are asking about PAM coding component and PAM modulation which gives multi-level output signal, you can use a visualizer at the output of the modulator to see the signal levels of the modulated signal and then use these levels to determine the threshold for the demodulator. For example, if the output signal from the modulator has two values of 1 and -1, the threshold at the receiver can be 0.
Regards