Instrument base class

Instrument base class for PLACE

class place.plugins.instrument.Instrument(config, plotter)

Bases: object

Generic interface to an instrument.

Any instrument that works with PLACE should use this as a base class. In face, PLACE will not execute instruments that do not use this as a base class.

config(metadata, total_updates)

Configure the instrument.

Called once at the beginning of an experiment. Instruments can expect to receive specific data relative to the experiment.

Parameters:

• metadata (dict) – PLACE maintains metadata for each experiment in a dictionary object. During the configuration phase, this dictionary is passed to each instrument through this function so that relevant instrument data can be recorded into it. Instruments should record information that is relevant to the entire experiment, but is also specific to the instrument. For example, if an instrument is using one of many filters during this experiment, it would be appropriate to record the name of the filter into the experiment metadata. PLACE will write all the metadata collected from the instruments into a single file for each experiment.
• total_updates (int) – This value will always be used to inform each instrument of the number of updates (or steps) that will be perfomed during this experiment. Instruments should use this value to determine when to perform specific tasks during the experiment. For example, some instruments may want to perform a task at the midpoint of an experiment and can therefore use this value to determine which update will represent the midpoint.

Raises:

NotImplementedError – if not implemented

update(update_number, progress)

Update the instrument for this step of the experiment.

Called one or more times during an experiment. During this method, the instrument should collect data or configure itself to support other instruments during this step. For example, oscilloscopes will usually take a reading, stages will usually move, vibrometers will focus, etc.

At the end of the update phase, the instrument may return the data to be saved into the data file. Returning data is optional.

Parameters:

• update_number (int) – The count of the current update. This will start at 0.
• progress (dict) – A blank dictionary that is sent to your Elm module

Raises:

NotImplementedError – if not implemented

cleanup(abort=False)

Called at the end of an experiment, or if there is an error along the way.

When this is called, the instrument should stop any activities and cleanup resources.

If the abort parameter is set, this indicates that the experiment is being abandoned, perhaps due to a safety concern, such as a problem with one of the instruments. In this case, halting all real world activity should be prioritized, and tasks regarding plotting, software resources or data integrity can be skipped.

Raises:NotImplementedError – if not implemented