Model Parameters doesn't work

Hello,

I'm trying to implement this Simulink example : http://fr.mathworks.com/help/comm/examples/qpsk-transmitter-and-receiver-1.html but for a different modulation.

My problem is the model parameters. I have put a SubSystem block, using Masking as the example above, with variables that I needed (for instance, M as M-ary number), but there is no link between these variables and the FSKModulation block. If I put M = 4 (in model parameters), there is no changing in the M of the FSKModulation block (M is still equal to 2). Any ideas ?

Thank you.

Best regards.