given frequency, right-click the time response plot and make sure Show filtered steady
state output only is selected.
Locate the source blocks in the model.
srcblks = frest.findSources(mdl,io);
Repeat the frequency response estimation with the source blocks disabled.
opts = frestimateOptions('BlocksToHoldConstant',srcblks);
[sysest,simout] = frestimate(mdl,io,in,opts);
frest.simView(simout,in,sysest,sys)
5 Frequency Response Estimation