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Message ID: 517     Entry time: Thu Apr 12 10:33:06 2018
Author: Gabriele 
Type: General 
Category: Vacuum 
Subject: Read-out of vacuum gauges 

I failed to interface in a reliable way the datalogger with Linux. So i hooked up the four analog outputs of the vacuum gauge controller to the fast ADC. The voltages are read and saved to disk at a reduced rate (16 Hz, throught the epics channels):

X3:CR0-VACUUM_VAC1_OUTMON
X3:CR0-VACUUM_VAC2_OUTMON
X3:CR0-VACUUM_VAC3_OUTMON
X3:CR0-VACUUM_VAC4_OUTMON

A python script running on the workstation (~/pycrime/automation_scripts/vacuum.py) reads the voltage every second and update four epics channels:

X3:CR0-VACUUM_CG0 = convection gauge of test chamber (high pressure gauge)
X3:CR0-VACUUM_IGM0 = ionization gauge of test chamber (low pressure gauge)
X3:CR0-VACUUM_CG1 = convection gauge of main chamber (high pressure gauge)
X3:CR0-VACUUM_IGM1 = ionization gauge of main chamber (low pressure gauge)

See below for an example during pump down (the test chamber is at a too high pressure for the IGM to work, so it returns a bogus number).

Here's an example of venting and pumping down

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