This is OK....but, the input matrix should come from the same place as the regular input matrix: i.e. it should be just another row like CARM, DARM, etc. rather than have its own screen.
You're absolutely right. That was a brain-fart oversight. I fixed the model so that the input from the lockin comes from another output row in the RFPD input matrix. I then fixed the C1LSC medm screen accordingly:
This is obviously much simpler and more straight-forward.
A future improvement would be to modify the DCPD input matrix to be able to route those signals to the lockin as well. This is actually currently possible since the DCPD input matrix is just a subset of the full input matrix, but it's not available via medm yet.