align_ZLP node to send warning to slack when slit adjustment >2 eV

[leginonbot]

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Author Name: Laura Yen (Laura Yen)
Original Redmine Issue: 7191, https://emg.nysbc.org/redmine/issues/7191
Original Date: 2019-04-10

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Can we get a feature in leginon for krios2 and krios3 where the align_zlp node will send a slack warning when the slit adjustment is greater than some value, say > 2 eV? Something to warn us that there is potentially some instability in the system (i.e. temperature changes in the room). This would be helpful since recently on 4/9/19 there was a change in our HVAC system that caused a warm up in the control room from 75.5 F to 78.5 F from 3AM to 6AM. This drastic change in temp caused the slit to become unstable, and slipping into many of the images on krios2 and krios3.