Thank you for your reply. I believe I wasn't clear enough. I want to extract the signal quality factor (Q=(P1-P0)/(sigma1+sigma0) )from the eye diagrams. I could also extract the BER.

I think I simply need to get rid of the inheritance of the PRBS order from the root element. But I haven't figured out how to do that yet. I can change from which parameter it inherits, but not simply delete the inheritance from anything. My goal ist to run a time domain simulation and to simulate several PRBS cycles. I hope that this would improve the statistics of the signal and that the calculation of the signal quality factor or BER results in the same value for each simulation. Right now it changes by an order of magnitude for the same optical link .