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The OMC GUIs

The OMC team uses several GUIs to help running data acquisition and analysis codes, each for a defined use:

  • The Beta-Beat GUI to perform analysis of measurement files and compute corrections.
  • The Kmod GUI to perform K-modulation, analyse data and export results.
  • The Multiturn GUI to perform beam excitation and data acquisition.
  • The Chroma GUI to determine chromaticity from RF scan analysis and compute corrections.

Of these, only the Beta-Beat GUI is currently developed by the team.

Running the GUIs

The GUIs can be started from your development environment or via deployed .jnlp from the archives:

The K-modulations GUI is now a Python app published with acc-py, and can be run with:

/acc/local/share/python/acc-py/apps/acc-py-cli/pro/bin/acc-py app run pykmodlhc

The Chroma GUI is a Python app published with acc-py, and can be run with:

/acc/local/share/python/acc-py/apps/acc-py-cli/pro/bin/acc-py app run chroma-gui

Warning

Please note these sites are currently available only to devices connected to the CERN network (see: workaround).

Open the .jnlp executable inside a browser, or call it with jws from the command line:

Compatibility Issues

Since javaws (java web start) causes trouble due to internal security mechanisms, a replacement named jws was developed and has to be used to run the jlnp file. For further information see the jws Confluence page.

Requirements

The following are required to run the GUIs:

  • A version of Java>=8.
  • The jws replacement for javaws (in case of errors, see below).

Info

Being inside of the TN is required for the KnobPanel. To do so, either ssh -X to the cs-ccr-dev machines or use the sshuttle method.

Kick Groups

To make use of the Kick-Groups, your machine needs to have /nfs and /user mounted, like the cs-ccr-dev and cs-ccr-optics machines.

Troubleshooting

You may encounter the following errors:

Running in the CCC in 2025

On the CCC terminals, there are some issues related to finding the correct java path, which affects NXCals extraction. To avoid this, close all windows and CCMs and then run:

/user/slops/data/LHC_DATA/OP_DATA/Betabeat/launch_ccm.sh

This script performs the following commands, which could also be done manually in a terminal:

  • Create a kerberos ticket: kinit lhcop
  • Adapt the path/set JAVA_HOME to use the correct java: export PATH=/bin:$PATH and/or export JAVA_HOME=/usr/java/jdk (either should be fine)
  • run ccm or /mcr/bin/ccm

Then select LHCOP and launch the Beta-Beat GUI from the new CCM window.

Problems with execution due to disabled Java

If you encounter a complaint about Java being too old, try using /mcr/bin/jws.

Failure

javaws https://bewww.cern.ch/ap/deployments/applications/cern/lhc/lhc-app-beta-beating-omc3/PRO/BetaBeatingOMC3-Control-3t.jnlp
Disabling Java as it is too old and likely to be insecure. To reenable use jcontrol utility

Success

/mcr/bin/jws https://bewww.cern.ch/ap/deployments/applications/cern/lhc/lhc-app-beta-beating-omc3/PRO/BetaBeatingOMC3-Control-3t.jnlp

Unspecific Error

Failure

Any random error

If so, check that you can import numpy from the OMC production Python environment. If this leads to the previously raised error, then the permissions are broken. Either fix the permissions on afs or ask someone to do so for you.