Kiwamu called, told me the laser was off.

    In what is becoming an all too often occurrence, the laser tripped again around 9 pm last night.

    The Beckhoff status screen is attached.  I checked the chillers: crystal chiller was off, diode
chiller was still running.

    Reset the laser, tried starting it.  It failed.

    Previously the suspect was perhaps one of the flow sensors in the power meter cooling circuit.
I decided to change one of the crystal chiller tripping points.  I changed the exception time from
000 seconds to 001 seconds.  Thinking that if a fast transient caused the exception then perhaps a
1 second delay might "filter" it out.  If there was a real problem with the flow rate then 1 second
might not make much difference before things shut down.  I need to check the chiller manual.

    Tried restarting the laser again but it failed.  I rebooted the Beckhoff PC and was then able
to start the laser.  No sooner as I had left the diode room, I noticed that the crystal chiller
was complaining about a "flow sensor problem".  I re-entered the diode room to check the laser status -
it was still on.  So it appears that the change in exception time did the trick (for now).

    My conclusion from this is that the vortex flow sensor in the crystal chiller is the prime suspect
at this stage and not a flow sensor in one of the laser's cooling circuits, since there is no external
signal feed back to the crystal chiller.  If it were an external sensor, the interlock box would have
kicked in.