General Machine Timing System at GSI and FAIR

The FAIR facility involves a long chain of accelerators which need to be tightly synchronized. This is achieved by the General Machine Timing (GMT) system, a distributed event generation system based on the notion of time. Time synchronization is achieved by using White Rabbit (WR), a fully deterministic Ethernet-based field bus for clock transfer and synchronization. The key components of the GMT are a so-called Data Master (DM) that schedules actions by broadcasting messages, a WR network and Timing Receiver (TR) nodes executing machine relevant actions on time.

The primary tasks of the timing system are the following.

• Time-Synchronization of ~2000 - 3000 nodes with sub-ns accuracy over fiber lengths of up to 2 km.
• Distribution of TAI counters with ns accuracy.
• Generation of timing events for synchronization of equipment.

About...

The aim of this timing web is to provide an overview on the timing system and its relationship to other systems. Moreover, it is the central point for documentation. Please note, that the timing system is still under development.

Topics

• Introduction
  • Accelerator Control System, Clocks and Time, Network Basics
• Getting Started
  • Essentials, Timing Receiver: ECA, Timing Receiver: Usage
• Documentation
  • Documents, HOW-TOs, Current Release, Releases, Getting an IP for Timing Receivers
• Acronyms

Announcements

Please checkout this mattermost channel.

Scheduled downtime of the GMT production system as agreed with operations are marked with bold letters. Non-bold letters are activities by others are only listed for information.

• DD-DD MM YYYY: maintenance window INN
• 2-6 Dec and 10-11 Dec 2024: "§88-Prüfung"
• 9 Dec and 12-13 Dec 2024: device testblock

Figure: Schedule for the next weeks based on shutdown planning. For an overview, click here or here.

News

• 16 Dec 2024
  • we have moved from https://www-acc.gsi.de/wiki to https://wiki.gsi.de
• 06 Dec 2024
  • minor maintenance
• 22 Nov 2024
  • maintenance window closed
• 21 Nov 2024
  • White Rabbit timing maintenance window
  • @UNILAC, roll-back ICU emergency system -> legacy system
• 08 Nov 2024
  • beam in UNILAC
  • beam through entire UNILAC up to the end of transfer channel
  • wetrun at UNILAC ends
• 04 Nov 2024
  • wetrun at UNILAC starts
• 01 Nov 2024
  • dryrun at UNILAC ends
• 21 Oct 2024
  • dryrun at UNILAC starts
• 22/23-Jul-2024
  • maintenance window closed
• 19-Jul-2024
  • dryrun at UNILAC ends
• 01-Jul-2024
  • dryrun at UNILAC starts ('Injector Controls Update')
• 28-Jun-2024
  • physics run ends
  • machine experiment with new White Rabbit -> MIL Gateways at UNILAC with beam
• 25-Mar-2024
  • physics run, first block ends
• 07-Feb-2024
  • physics run starts (first block til end of March)
• 02-Feb-2024
  • commissioning with beam
  • beam is back in SIS18!
• 22-Jan-2024
  • commissioning without beam starts
• 20-Dec-2023
  • engineering run 2023 ends
• 06-Nov-2023
  • start engineering run 2023
• 03-Nov-2023
  • beam extracted from SIS18
• 30-Oct-2023
  • commissioning starts
• 13-Oct-2023
  • dryrun ends
• 02-Oct-2023
  • dryrun starts
• 08-Sep-2023
  • dryrun ends
• 04-Sep-2023
  • graylog finally turned off (click)
  • turning off graylog triggered a bug in saftlib, scu frontends inoperational after reboot
  • -> hotfix for saftlib bug on 5 September
  • dryrun starts
• 01-Sep-2023
  • database issues, configuration of ip-backend frozen
  • -> fixed 4 September
• 28-Aug-2023
  • device testblock starts
  • some White Rabbit Switches (area EX2) seem to be down; DHCP issue, fixed
  • some SuperMicros (B2B System) are not available; DHCP issue, fixed
• 24-Aug-2023
  • White Rabbit network down due to an unexpected major power-cut at GSI (and in a larger area around GSI)
  • network comes back during the afternoon
• 15-Aug-2023
  • maintenance window closed
  • main GSPDO reinstalled; White Rabbit and BuTiS switched to main GPSDO
• 20-Jun-2023
  • maintenance window closed
• 19-Jun-2023
  • maintenance window open
    • White Rabbit Switches: replacement of broken fans
    • White Rabbit Switches: firmware and config upgrade
    • DM Swap tested
    • main GPSDO removed (sent to upgrade); White Rabbit and BuTiS switched to backup GSPDO
• 09-Jun-2023
  • dry-run ends
• 05-Jun-2023
  • device testblock ends
  • dry-run starts
• 30-May-2023
  • device testblock starts
• 22-23-May-2023
  • replaced some broken fans of White Rabbit Switches at TH2 (CRYRING)
  • replaced some broken fans of White Rabbit Switches at BG1.016
• 09-May-2023
  • restart data master
• 28-Mar-2023
  • maintenance window closed
  • replacement GPSDO systems
• 18-Jan-2023
  • White Rabbit @ UNILAC is back
• 12-Dec-2022
  • power-cut in the UNILAC area, see (here)
  • White Rabbit @ UNILAC is down
  • a part of the 'USER' network is down
• 05-06-Dec-2022
  • maintenance window closed
• 5-7-Oct-2022
  • urgent maintenance on White Rabbit switches
• 30-31-Aug-2022
  • maintenance window closed
• 04 July 2022
  • begin of shutdown activities
• 30 June 2022
  • end of beam-time 2022!
• 09 May 2022
  • user beam-time (next part)
• 02 May 2022
  • machine experiments
• 25 April 2022
  • beam commissioning starts
• 19 April 2022
  • operator training ends
  • maintenance break
• 16 April 2022
  • first part of beam time ends
  • operator training til Monday
• 05 March 2022
  • restart Data Master
• 01 February 2022
  • user beam-time starts!
• 28 January 2022
  • beam commissioning starts
  • beam extracted from SIS18
• 24 January 2022
  • maintenance window open and closed
• 21 January 2022
  • dry-run ends
• 17 January 2022
  • dry-run starts
• 22 December 2021
  • more tests with 'booster mode'
  • -> good transfer timing from UNILAC to SIS18 can be achieved with an efficiency exceeding 98% (click)
• 16 December 2021
  • maintenance window closed
• 15 December 2021
  • maintenance window open
• 03 December 2021
  • dry-run ends
  • we had two weeks of smooth GMT operation
• 23 November 2021
  • booster mode
    • for the first time, the so-called booster mode has been demonstrated (dry-beam)
    • dry-beam is injected, accelerated and extracted from SIS18 with a repetition rate of 2.7 Hz
    • the key challenge is tight synchronization of SIS18 and the 50 Hz machine UNILAC at this high rate
• 22 November 2021
  • dry-run starts
  • new handshake mechanism Data Master <-> UNILAC Pulszentrale successfully established
• 05 November 2021
  • maintenance window closed
• 03 November 2021
  • Fallout 6.2.0 released! click
• 01 November 2021
  • maintenance window starts (full week)
• Older News

GSI Timing Team

-- DietrichBeck - 22 November 2024