Startup Sequence

Calling xxxpython is an alias for calling hutch-python --cfg cfg.yml. The cfg.yml file defines what the loader will do. The specifics of this file are documented on the yaml files page.

Each step of the startup can freely access any objects defined by previous steps. In order, the startup sequence is as follows:

• Common Startup

  • Set up log files, debug state, and sim state

  • Read cfg.yml

  • Display the xxxpython banner

  • Create and set up a RunEngine as RE

  • Create the plans object with default plans and alias to p

  • Create the daq object

  • Create the scan_pvs object

• Database Load

  • Load the db from cfg.yaml using happi

  • Create the xxx_beampath object using lightpath

  • Create cameras using the camviewer configuration file

• Beamline Load

  • Import all objects from the modules under load in cfg.yaml. By convention, this is just xxx.beamline, but it can also be extended to a list of modules.

• Experiment Load

  • Automatically select the hutch’s current experiment if one was not provided in the cfg.yml.

  • Create user objects from the experiment questionnaire using happi and psdm_qs_cli.

  • Import User class from experiment file and instantiate User().

  • Attach all questionnaire objects to the User() object

  • If there was no experiment file, make a SimpleNamespace() object instead

  • Set this object to be x and user.

• Groups Load

  • If any EpicsMotor objects were defined previously, group them into a motors object. Alias this to m.

  • If any Slits objects were defined previously, group them into a slits object. Alias this to s.

  • Group all loaded objects by metadata, to be found in a tab-accessible way e.g. xxx.dg1.name

  • Group everything into an all_objects object. Alias this to a.

• Finish

  • Create all _debug objects as documented on the debug page.

  • Enable input, output, and error logger

  • Enter the ipython terminal