I ran some simple tests today to test out the PCALX_STAT Guardian node.
I started to test things at 17:00 UTC but ran into a collision with Jim's measurements.
During the first attempt I was able to determine that the shutter closing will cause the PCALX_STAT guardian to go to a FAULT [37] State after 60 Seconds.
It then cycles between waiting [4], and Nominal_PCAL[10] and Fault mutiple times per second until the fault is resolved. I have remedied this issue.
After Jim finished his work, I was able to continue testing the guardian using a few other buttons.
 

Potential PCAL Failure modes:

Things I've tested:
If the channel: H1:CAL-PCALX_OSC_SUM_ON gets turned off then the PCAL_STAT Gaurdian alarms because it is checking for this . This channel is also being monitored via SDF.
H1:CAL-INJ_END_SW  channel being switched from X to Y does not trigger a fault but this is being Monitored via SDF.
H1:CAL-INJ_MASTER_SW channel is also monitored via SDF.

OFS Loop Open check worked well by checking to see if this H1:CAL-PCALX_OPTICALFOLLOWERSERVOENABLE channel is set correctly and checking the H1:CAL-PCALX_OFS_PD_OUT16 voltage against a known threshold. Guardian worked well.
TXPD  H1:CAL-PCALX_TX_PD_WATTS_OUTMON  and or RXPD H1:CAL-PCALX_RX_PD_WATTS_OUTMON could have some fault in their signals.  the Guardian worked well for this as well.

H1:CAL-PCALX_SWEPT_SINE_ON could be turned off. This channel is currently not being monitored. potential solution is to just monitor it via SDF.  I will be waiting for an oppertunity to change this during the next Lockloss.

Edit: It may be easier to have the guadian check this channel.


Things I have not tested.
If the Laser Diode Current increases or decreases.  I do have a threshold for this outside of which the Guardian will go to Fault.
I the Laser Diode Temperature increases or decreases. I do have a threshold for this as well.
If the H1:CAL-PCALX_OFS_PD_OUT16 falls out of threshold. I do have a check for this in the Guadian but I have yet to test this.