Control of the ALICE permits, Post Mortem & BCM FSM configuration

News:

  • Please note that there is a new step: "Verify the BCM trends" in the "Post Mortem" and "Beam permit" procedures. The instructions are in the section: "How to verify the BCM trends"

Post Mortem procedure for DCS shifters

  • The diagram below presents the BCM system logic (upper half) and shifter's action (lower half) after Post Mortem occurs:

BCM_Processes.png

Manual control of the permits

  • Before arming the injection permits, make sure ALICE is SAFE/SUPERSAFE. Discuss with DCS On-call/ Shift Leader any exception.
  • Navigate to the FSM node ALI_DCS\LHC\DCS_BCM\BCM_TELL1\myTell1_BCM ( A) and double click on it to open the panel. Click the button B (…) to open the popup panel with manual control of permits:

beam2.PNG.

  • Use the buttons C to operate the permits. Click the 'Enable' button to activate the permits removal buttons:

manual.PNG

Beam permit

If the beam background in ALICE is above a safe level then the BCM will dump the beam and make the beam permit FALSE (red).

IF

  • BEAM PERMIT IS FALSE (RED)

beam1.PNG

THEN

  • IT IS NECESSARY TO REARM THE BEAM PERMIT MANUALLY

ACTIONS:

  • 1. Inform Shift Leader

  • 2. If you are during the Post Mortem procedure (there is Post Mortem popup panel and ALI_DCS\LHC\DCS_BCM FSM node is in state DUMP) then wait until it finishes.

  • 3. Navigate to the FSM node ALI_DCS\LHC\DCS_BCM\BCM_TELL1\myTell1_BCM ( A) and double click on it to open the panel:
    beam2.PNG
  • 4. Click the button B (…) to open the popup panel with manual control of permits: beam3.PNG
  • 5. Press the button C. The beam (user) permit should move to TRUE (green). If you do not succeed then call DCS On call.
  • 6. Verify the BCM trends (instructions below).

How to verify the BCM trends:

  • 1. Navigate to the FSM node ALI_DCS\LHC\DCS_BCM\BCM_TELL1\myTell1_BCM ( A) and double click on it to open the panel: . Open the "Sensors" (B) tab. Use four buttons (C) to display the BCM trends one by one. nav2.PNG
    • a) For the RS32 trends: check if there is a peak of values on the plots that exceed the level of 20 nA (you should see a peak like D which corresponds to the time of the dump). Note the values of peaks
    • b) For the RS2 trends: check if there is a peak of values on the plots that exceed the level of 1000 nA. Note the values of peaks. plot_view.PNG

  • 2.
    • If there is NO peak above 20nA on the RS32 plots and NO peak above 1000nA on the RS2 plots and ALICE dumped the beam (the beam permit was removed) then call DCS Oncall.
    • If there is a peak above 20nA on RS32 plots OR a peak above 1000nA on RS2 and the beam permit was NOT removed then call DCS Oncall.
  • 3. Note in the shift report the values of the all the peaks.

Reminder of some BCM & Post Mortem procedures for DCS Shifters:

A. There are several situations when status of the ALICE permits may change:

  • LHC injection handshake,
  • CCC (via Shift Leader) asks for giving the permits manually,
  • Post Mortem
  • arming of the Beam Permit after Post Mortem triggered by ALICE
  • manual removing of the injection permits on Shift Leader request

Shifter should verify then on the alarm screen if there is no alarm related to lhc_exchange project. There are 2 obsolete alarms from lhc_exchange: FSM summary (from 2008 and 2009) - do not worry about them.

By default the manual rearming of the injection permits can be performed only if ALICE is SAFE/SUPERSAFE and CCC expects them. For some LHC tests when the injection is not planned the permits might be armed irrespective of the SAFE/SUPERSAFE state (only on Shift Leader explicit request!).

B. In case of communication problems (alarms, problem with giving the permits) the shifter can:

  • 1. Give the permits using emergency button if CCC is expecting them (TWIKI, FOLDER)
  • 2. Try to restore the communication using recovery button (DCS GUIDE, FOLDER)
  • 3. Check what is the true status of permits/transient recorder using manual report (on the panel ali_dcs\lhc\dcs_bcm\bcm_tell1) - upon Oncall request

DCS On call should be immediately informed.

POST MORTEM:

Post Mortem:

  • can occur anytime
  • it implicates the injection permits are removed automatically
  • if ALICE BCM caused the beam dump then also the Beam Permit is removed
  • Post Mortem last ~ 3 minutes

After the Post Mortem the shifter should check:

  • if permits were rearmed if necessary (i.e. ALICE is SAFE and ALICE is during injection handshake)
  • if there is no alarms related with LHC exchange project (up to 6 minutes after the Post Mortem procedure started)
  • the status of the Beam Permit. If it is red, then arm the Beam Permit manually, inform Shift Leader and DCS oncall (by email during the night)
  • peaks on the BCM trends

The injection permits are rearmed automatically after Post Mortem when:

  • ALICE is SAFE and
  • ALICE did not caused the beam dump and
  • LHC injection handshake is in 'injection' phase (the status is ‘LHC injection ready' or 'LHC injection imminent' after the command 'CONFIRM inject' has already been sent from ALICE)

Reminder of some BCM & Post Mortem procedures for DCS ON-CALLs:

In case of problems with communication of BCM (giving the permits, alarms)

1. Restart the communication:

  • Use recovery buttons (if shifter did not use them so far) (DCS GUIDE)
  • Restart of the PVSS manager bcmMonitorSensors with PVSS console on alidcscom042 (DCS GUIDE)
  • Restart the project - follow the instructions: Restart of the LHC_EXCHANGE project
  • Only if BCM experts are not available and it is absolutely critical: restart the VME with Tell1 (panel: ALI_DCS\LHC\DCS_BCM\BCM_INFRA\BCM_VME+ after few minutes restart the project + reupload thresholds table to Tell1
2. Write an email to Mateusz + Giacinto

The "CCPC is not accessible" alarm indicates communication problems. It can be removed manually in PARA on alidcscom042 - after successful recovery and when investigation is finished.

Configuration of BCM FSM

Please note that FSM nodes: BCM_SIDE_A and BCM_SIDE_C are excluded from LHC\DCS_BCM and should remain in state DEAD

bcm_dead.PNG

Emergency control of the permits

Use this procedure only if the normal BCM recovery fails and after DCS On-call approval

IF

  • There is a problem with giving the permits and LHC expects them (i.e. injection handshake is in underway), ALICE is SAFE/SUPERSAFE

THEN:

  • 1. Navigate to the FSM node ALI_DCS\LHC\DCS_BCM\BCM_TELL1\myTell1_BCM ( A).

  • 2. Click the button Emergency Control ( B).

  • 3. Follow the instructions from popup panel ( C).

emergency.PNG

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Topic revision: r2 - 2010-11-03 - MateuszLechman
 
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