Details
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Type:
Story
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Status: Done
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Resolution: Done
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Fix Version/s: None
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Component/s: None
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Labels:
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Story Points:3
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Epic Link:
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Sprint:TSSW Sprint - Jan 17 - Jan 31
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Team:Telescope and Site
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Urgent?:No
Description
The ATCamera needs a monitor (with warnings) for the sensor temperature and vacuum pressure.
The vacuum limit is a bit tricky because the system "burps". So basically the system should remain under 1e-6 at all times, but calculated as a moving average (median?) over a time interval. I think that time interval can be ~10-15 minutes.
The CCD temperature limit should be -94C +/1 over a period of a few minutes.
Coldplate can issue an alert when the temperature is greater than -110.
The cryohead is harder, lets say it should have an alert when the temperature is greater than -140.
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So all the data we're interested in can be seen in the following dashboard.
https://chronograf-summit-efd.lsst.codes/sources/1/dashboards/14?refresh=Paused&lower=now%28%29%20-%202d
The vacuum limit (lsst.sal.ATCamera.vacuum.vacuum) is a bit tricky because the system "burps". So basically the system should remain under 1e-6 at all times, but calculated as a moving median over a time interval. I think that time interval can be ~10-15 minutes
The temperatures are easier.
The CCD temperature(lsst.sal.ATCamera.vacuum.tempCCD) limit should be -94C +/1 over a period of a few minutes.
Coldplate (lsst.sal.ATCamera.vacuum.tempColdPlate) can issue an alert when the temperature is greater than -110.
The cryohead is harder (lsst.sal.ATCamera.vacuum.tempCryoHead), lets say it should have an alert when the temperature is greater than -140?
More information: the mean cryo_head temperature is about -143 C and the mean cold plate temperature is about -112 C. Patrick suggests the following severity thresholds (which replace the ones suggested above, where there is a conflict). These will probably need to be tweaked as we learn more about the system:
- max_warning_cold_plate_temp: -108
- max_critical_cold_plate_temp: mean + 8 = -104
- max_warning_cryo_head_temp: -140
- max_critical_cryo_head_temp: mean + 15 = -128
The CCD thresholds are based on a setpoint of -94 C. This is hard-coded in the controller and will not change, but our ranges may still need to be tweaked:
- min_warning_ccd_temp: -95
- min_critical_ccd_temp: -97
- max_warning_ccd_temp: -93
- max_critical_ccd_temp: -91
Pull request: https://github.com/lsst-ts/ts_watcher/pull/43
Reviewed in GH. Comments can be found there.
Merged to develop. I will hold off release for DM-33384
Patrick Ingraham: please spell out which telemetry (and event?) topics and fields to use for the suggested inputs.
If there are multiple sensors for a given item, how do you suggest combining them: average? median? most pessimistic? second-most pessimistic (as a crude form of outlier rejection)?