TJ/Jason pointed out in alog 50741 and we re-discoved in alog 60850 is that the set point given to the chillers (H1:TCS-ITMX_CO2_CHILLER_OUT_GAIN_INMON) is 20deg but the chillers are receiving set point request of 22degC (H1:TCS-ITMX_CHILLER_SETPT1). This was the case during observing too. 

I'm struggligng to see how these two setpoint values are linked but from the h1tcscs simulink CHILLER_OUT_GAIN filter goes to DAC0 as CH4 (ITMX) and CH12 (ITMY).  These are both reporting overflows (and have for the last two years). CH0 and CH1 (AOM and PZT) also overflowing. Jeff points this out in alog 60550 that they are saturing early at +/-27000 counts out of 32000. Tagging CDS for help.