Instrument temperature cron management

These tasks should ONLY be done by engineering, DO NOT attempt these tasks otherwise

Spex has two cronjobs running on the computer 'messier' that queries the database server for 
temperature sensor data . messier is located in the remote observing room at IfA-Hilo. The normal 
way to edit cronjobs is through the crontab tool, which is called on the commandline, 
combined with some of its optional arguments. 

The following instructions will show you how to disable the cronjobs by clearing crontab,
and bring the cronjobs back online later.

Note: Verify that Spex's temperatures have reached normal operating temps before restarting
the cronjobs, otherwise the cronjobs may be triggered erroneously

Current limits for Spex:
Ch 1 (coldhead): 55 Kelvin
bd_sdat (LN2):   75 Kelvin

Deleting cronjobs
1. Open an xterm in any IRTF Linux machine and SSH into messier as the user spex. Password is
   the project password.
	
   ssh spex@messier

   -Alternatively if you are at IfA you can head into the remote observing room and log 
    in to messier

2. Clear the crontab
	
   crontab -r
	
   -The crontab is now empty with no active cronjobs. You can enter crontab -l to verify. 

3. Enter exit to close the SSH connection or logout of the messier computer

Restarting cronjobs
1. Open an xterm in any IRTF Linux machine and SSH into messier as the user spex. Password is
   the project password.
   
   ssh spex@messier

   - Alternatively if you are at IfA you can head into the remote observing room and log
   in to messier

2. Change directories into the instruments temp monitor directory
	
   cd bin/tempmonitor

3. Give the crontab a text file with the default cronjob listings

   crontab cronjob.txt

   cronjob.txt is a text file that contains the default configuration for the instrument
   cronjobs. Giving crontab the name of a file will read it into the crontab and save it.
   The instrument chronjobs should now be back online. Enter crontab -l if you'd like to 
   verify.

4. Enter exit to close the SSH connection or logout out of the messier computer