Tools for setting up the LCLS live models.
https://slaclab.github.io/lcls-live/
This is to facilitate caching of EPICS values and offline usage. Basic usage:
from LCLS.epics import epics_proxy
epics = epics_proxy('data/epics_cache.json')
val = epics.caget('some_pv_name')
vals = epics.caget_many(['pv', 'name', 'list'])lcls-live is packaged with a command line tool for generating tao commands from live or archived EPICS process variables. This command may be executed using epics:
$ get-lcls-live --tao --beampath cu_hxr --source epics > cmd.tao
And with archiver:
$ get-lcls-live --tao --beampath cu_hxr --source archiver --isotime '2021-04-21T08:10:25.000000-07:00' > cmd.tao
At present the tool accomodates --tao or --bmad options for generating commands, --beampath cu_hxr or --beampath cu_sxr, --source archiver or --source epics.
Access to production process variables requires setting of the $CA_NAME_SERVER_PORT, $LCLS_PROD_HOST, and $SLAC_MACHINE. The utility script configure-epics-remote is installed with lcls-live. The script will perform forward local connections to the $CA_NAME_SERVER_PORT to the $LCLS_PROD_HOST via a double hop ssh and will required entry of your SLAC password. The process will run in the background and will require manual kill, identifying the pid with ps aux |grep ssh.
$ configure-epics-remote
The remote archiver requires an ssh tunnel, which can be configured using the configure-archiver-remote script installed with lcls-live. This should be executed in a separate shell from the Tao command and the process allowed to continue for the duration of archiver use. The script requires setting the $SLAC_ARCHIVER_HOST and $SLAC_USERNAME environment variables.
$ configure-archiver-remote
A utility notebook for generating datamaps is provided in developer/build_datamaps.ipynb. This constructs relevant datamaps using the pytao Tao interface and requires setting the $LCLS_LATTICE and $ACC_ROOT_DIR