SQUID tuning on DCRC v3

Zero driver offset, SQUID bias, lock point, and QET bias.
Set output gain = 1
Choose polarity grounded or open loop
Choose signal source feedback
Turn on test signal and connect it to the feedback line of the channel you are tuning.
Choose external trigger mode in the readout vi, then you should see triangle wave on the scope. Now go to the responsivity window.
Go back to the control vi and switch signal source to preamp
Increase the SQUID bias until you get the maximum modulation depth on the readout vi
Choose a point on the modulation with the largest slope but make sure to avoid squid resonances and there is enough dynamic range
Adjust the lockpoint to bring the lock point you chose in the last step to 0
Switch signal source to feedback and change polarity to non-inverting/inverting to close the loop. Now you should see a triangle wave on the scope.
Disconnect test signal from this channel
Adjust the lockpoint to bring the DC level to 0
Them maximize the output (PGA) gain. If you didn't bring the DC level as close to 0, the signal may have a large DC offset after maximizing the output gain.
Maximize the frontend (VGA) gain without causing the circuit to oscillate. Higher loop gain would increase the noise, this can be filtered in data processing.
Adjust the QET bias to get decent phonon pulses.
You are done with this channel.