Once you have determined the names of your detectors and EPICS variables (ideally using the simpler aliases, where possible) you can fetch your data by passing those names to psana's "Detector" interface which gives you simple access to often complex detectors.  The subsections here show various examples of accessing data.

Documentation of this interface can be found here.

One can explore the data (without reading documentation) using ipython tab-completion, as shown here.

NOTE: if you open multiple psana DataSource's at the same time (very few people do this) it is important to pass the optional DataSource.env() second argument when creating a Detector object.

References

• Detector documentation - python interface to access LCLS detector data.