Minutes of the 6^th Timing Working Group Meeting (TimWG)
Held on Wednesday the 25^th June 1999

 Present:

Excused:

            Philippe BAUDRENGHIEN

Agenda

• Approval of previous minutes
• Timing Policy for Electricity Control. Arthur SWIFT
• Timing Requirements for the Experimental Areas. Guy BARIBAUD
• Next speakers & next meeting

Approval of previous minutes

There was no comments on the previous minutes.

Timing Policy for Electricity Control

Soren POULSEN presented the actual architecture of the electrical service control system. It is composed of a network control center (NCC) on the top level and a set a equipment specific control devices at the bottom. The actual system is based on the SL/CO front-end, but the intention of ST/EL is to go in the future to a fully integrated industrial solution. Their major requirement is to have a correct time synchronization at the devices level for the different type of equipment. Soren POULSEN explained their intention to implement a top to bottom synchronization / re-synchronization mechanism based on the top level on a GPS time reference system and a distribution of time event through the different communication bus to the equipment. Their basic requirements are the following:

• 1 ms time stamp event with a re-synchronisation each minute for a specific device,
• 10 ms accuracy between different type of devices.

Michel JONKER asked to Arthur SWIFT if a mechanism for trace back correlation of machine error to the electrical source will be possible. He replied that actually nothing is foreseen but that this kind of facility can be useful and need a good time synchronization.

Arthur SWIFT asked if the SPS Super Cycle Reset will still be available in the future. Michel JONKER replied  that the Super Cycle Event event will not be generated anymore but that elementary cycle identification events will be generated. It appeared that the connection of the electrical service to the machine timing must be clarified and discussed more in details.

Timing Requirements for the Experimental Areas

Guy BARIBAUD presented the different timing signals needed in the SPS north and west experimental area:

• 1 khz clock with 10 us precision,
• Timing events with a resolution a 1 ms and a precision of 10 us.

He explained that SPS experimental area don't have specific timing requirements in the frame of the LHC project.

He outlined also the importance to receive continuously the different timing events even if the beam is not available for equipment setup and calibration. Michel JONKER explained that in the frame of the SPS2001, it is actually not foreseen to generate events if the related beam is not produced. Guy BARIBAUD said that this approach is not acceptable. Julian LEWIS suggested to use the telegram mechanism actually used in the PS in order to generate virtual local timing. It has been decided that this question has to be followed-up by the SPS2001 project.

AOB

Gary BEETHAM updated the summary (see slide attached) of the slow timing requirements. He asked the members of the working group to control
and complete if necessary, the document.

Next meeting

Next Meeting will be held on Friday 09 July 1999 at 09:30 AM in 864 1C01.

Agenda

1. Approval of previous minute
2. Timing transmission over the WorldFIP bus. Quentin King (SL/PO) & Raymond Brun (SL/LRF)
3. Next speakers & next meeting
4. AOB