Data tab

The Data tab is the first one. It says where the data goes (the database folder and the sample), where the QCoDeS log is written, and it is the explorer of everything that was measured: experiments, runs, tags and notes.

Database and Experiment Info 

Database folder: The folder where the databases are kept. Choose it with Browse….
Sample name: The name of the sample you are measuring. Databases are named after it: <sample>_<NN>.db, with NN two digits, for example Hall_bar_00.db. Spaces and other unsafe characters become _. You never type a database name.
Database file: The database the next measurement is written to. It lists the existing databases of the folder; the empty entry means a new database, which is created when the first measurement starts. Selecting an existing database lets you continue in it.
Database size: The size of the selected database. A database that grows above 750 MB is closed: the next measurement starts the next one of the series (Hall_bar_01.db). This keeps every file small enough to copy, back up and open quickly.
Upgrade database: Starts the next database of the series now, whatever the size of the current one, for instance when you change something in the setup and want a clean file. It is not available while a measurement runs.

The Instruments tab opens as soon as a database folder and a sample name (or an existing database) are given.

Logs 

Logs folder: The folder for the log files. The QCoDeS log (every command sent to an instrument, warnings, errors) is written there, and so are the log files of the Monitor.
Start logging: Starts the QCoDeS logger with its file in that folder. Do it at the beginning of a session: the log is the first place to look when an instrument behaves strangely.
View Logs: Opens the log viewer: pick a file, filter by instrument, by minimum level (errors included) and by text, and select a record to read all of it, traceback included.

The Experiment Explorer 

Below the database information, the explorer lists what is in the selected database. Choose an experiment (the Experiment Name of the Measurement tab groups related measurements) and the table shows its runs:

Column	Meaning
ID	the number of the run in the database
Name	the measurement name, with a coloured dot if the run is tagged, and the first line of its notes
Started	the date and time the run started
Status	completed, or not completed (a run that was interrupted)
Points	the number of points written

The experiment explorer with the runs of an experiment, two of them tagged — The experiment explorer. The first run is tagged green, the third red and has a note.

Tags and notes

Right-click a run to open its menu:

The row of six coloured dots is the tag: click a colour to tag the run, and click the same colour again to remove the tag. Use colours as you like, for instance green for good runs and red for bad ones.
Add notes… / Edit notes… opens a text box for free notes on the run; Delete note removes them.
Compare with another run and Load snapshot, below.

Tags and notes are saved in the database, with the run, as QCoDeS metadata. They can also be changed from the live plot of the Measurement tab once a run has ended, and the table here follows.

Comparing two runs

Select a run and click Compare with another run, then pick a second run (from any database; it is only read). mesoscoPy shows what differs between the snapshots of the two runs: the values of the instruments, the definitions of the experiment parameters and the setup of the Measurement tab. It is the quickest way to find out what changed between a good run and a bad one.

Loading a snapshot

Every run stores a snapshot: the state of all the instruments and the setup at the moment it started. Load Snapshot brings a run’s setup back: it connects the instruments of the run, restores their settings and the experiment parameters, and fills the Measurement tab as it was. Nothing is run, and you review every change in a window before anything is written to an instrument. It is unavailable while a measurement runs, since it sets instruments.