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EMC Slow Controls FAQ
P-A Fischer
Last Update July 21 1999


  • How do I know that the alarm I see is real and not a monitoring artifact ?

  • Before we go into details, let me just say that any Real alarm will have consequence on data taking (loss of efficiency in a group of channels, increase of noise, etc). It is therefore always wise to check the fastmonitoring if there is new data coming in to confirm the diagnostic delivered by the slow monitoring.
    Here's a list of know monitoring artifacts.:
    • A single channel value dropping close to zero. This applies to all types of channels, but especially to the low voltage monitoring (currents and voltage).Be careful though, it could still be a real alarm. Check with the expert.
    • A single channel oscillation. This is definitely an artifact. Watch it closely. If it's a temperature and it goes out of range periodically, it should be masked out or fixed quickly.
    • A group of  8 channels oscillation. This is usually fixed by switching of the gmb board power for a few seconds and switching it on again.
    • A current value of more than 10 Amps. This is definitely a monitoring problem. The GMB full scale for current readings is around 10 amps. If this happens: mask the alarm and contact the monitoring expert by e-mail.
    And here's a list of known real alram symptoms
    • All readings for one power supply drop to zero(V(-5V),I(+5,-5,10), except the temperature reading. A power supply has tripped or is dead. GO to the EH and try to switch it on again. If this doesn't work try replacing the power supply.
  • My monitoring display is blinking white, what does that mean ?

  • Communication was lost between the workstation and the Epics I/O controller. This can be caused by  network problems or loss of one  monitoring hardware device (GMB).  Wait for at least 30 seconds before doing anything. That's about the time it takes for the update of the sensors value to be completed. If after a minute or two the display is still white, Try cycling the GMB power in the EH (recipe).
  • My monitoring display is full of white boxes with the "Not Connected" mention, what does that mean ?

  • No connection Image
    This is a network problem or the IOC has been rebooted.. In this case only one thing to do. First make sure we do not experience  afs problems. This could cause the monitoring not to restart because the boot file is located under afs space. Then go in the electronics house and reset the IOC if it hasn't been done yet. You can see that it restarted when the green LEDs on the CAN module start blinking again. This might take a while. See Instructions here
  • I start the monitoring display by typing ~paf/mon.sh but it dies right away with an error message, what do I do ?

  • If netscape is running, kill it. Restart netscape with the -install option. restart the monitoring.