A little piece of script, deModMonitor.py, which helps you monitoring demodulated signals, is available at 

/opt/rtcds/userapps/release/isc/h1/scripts/demodMonitor.

An example of how this code can be used is TCS_deModMonitor.py and run_TCS_deModMonitor.sh. The main purpose is to monitor how omc dcpd's response w.r.t. intensity noise (, or frequency noise or src length noise) changes when we heat up the compensation plates. A sinusoidal excitation is generated using Chris Wipf's awg module and injected to PSL-ISS_TRANSFER1_INJ. The code then reads out OMC DCPD's demodulated signal every certain amount of time and records the data to a txt file. In case that the code needs to be terminated during a measurement, it will catch ctrl+c and turn off the excitation.

The code is designed s.t. it should be able to used in a general demodulating-monitoring process.