Interlock System

PVSS project

Starting FSM

Procedure after a powercut

1. Log on to windows terminal in the online network.
   
2. Open the directory G:\online\ecs\Shortcuts\VELO
   
3. Double click on VEDCSHV_UI_FSM
   
4. The following window appears:
   
5. expand VELOA/C_DCS
   
6. right click on VELOA/C_DCS_TB
   
7. take control by cliking the padlock
   
8. click on the Interlock circles (repeat the next 9 steps for all the three circles)
   
9. you will be prompted with the question "Do you want to change the ELMB state?", answer YES (preoperational)
   
10. You will get the Status_and_Event_reg window.
    
11. click on Check status (in commands frame), you will see all channels are masked (the mask box is ticked)
    
12. click on reset board, and then load mask configuration (both buttons are in the Commands frame)
    
13. check status again and you should see that the 4 interlocks fired.
    
14. click on the Send button in the Control Register Reset frame
    
15. To make sure that everything is ok (ie that the interlocks have gone) check status again
    
16. Close the panel
    
17. Switch on the Board again (click in the state of the corresponsing board and select "Switch_ON", in the VELOA/C_DCS_TB panel). The state becomes ready and the status of the ELMB becomes OPERATIONAL.
    

How to know when an interlock fired?

• An Easyboard goes into error
  

What to do when an interlock fired?

1. Verify that the cooling is operational,
   • if not switch on cooling (Cooling instructions),
   • if yes continue with the next steps
     
2. Open the panel VELOA/C_DCS_TB
   
3. When an interlock fired because of the Temperature Boards the Interlock circle in the panel VELOA/C_DCS_TB will be RED
   
4. click on the Interlock circles (repeat the next 6 steps for all the three circles)
   
5. you will be prompted with the question "Do you want to change the ELMB state?", answer YES (preoperational)
   
6. You will get the Status_and_Event_reg window.
   • You will see some red fields in the panel (red fields do not matter when channels are masked);
   • In the status register frame you will see which interlock(s) fired;
   • In the control register reset you will see the corresponding interlocks and errors ticked, and the reset byte field filled with the right bit pattern.
     
7. click on Check status (in commands frame)
   
8. Click on Send in the Control Register Reset frame
   
9. Check status again
   
10. If you are lucky you will get everything OK (green), if not call an expert.
    

Trouble shooting

• Hardware interlock signals coming from the temperature boards, Vacuum (forced until further notice, 28/05/2008), Cooling and BCM system (forced until further notice, 01/08/08) and to the LV and HV (taken out until further notice, 01/08/2008) systems, are treated into the interlock unit. See picture below:
  
  • This unit is located in D3E05 slot 6.
  • The input signal Leds (not the spare channels) on the from panel can have 3 states:
    • green - OK
    • orange - signal forced
    • no green nor orange LED on - interlock signal fired.
  • The output signal leds (not the spare channels) can be green (ok) or off (interlock fired)
• Hardware interlocks between the PLCs (cooling-vacuum, vacuum-motion) are treated directly. An interlock status panel can be seen on the corresponding PLC.
• The vacuum PLC receives status information from the LHC vacuum
• The motion system is interlocked to the LHCb beam dump signal
• More detailed information on all of the above topics can be found in https://edms.cern.ch/document/925824/1
  

-- AnnVL - 01 Aug 2008