Continued troubleshooting the Demodulator readback signals for the green WFS at the end stations. Traced issues to faulty Beckhoff analog input terminals - EL3104.
EY - EL3104 Terminals 6 and 9 were replaced
EX - EL3104 Terminals 6, 7, 8 , and 9 were replaced. I don't expect all four units to be bad, but was easier to replace all four at once.
Units removed will be tested to see if we can reproduce/diagnose the problem.
One thing to note is that the RF Mon channels at EY were not as stable as EX. The LO mon signals at EY (15dB) had a 3dB difference than EX (18dB). Not sure if this is an issue or just the state of each end station at the time of testing.