Bench configuration file

The bench configuration file describes the instruments that are available on an experiment bench. It is a YAML file containing a dictionary. It is parsed during the initialization of an ExperimentFactory.

Typical bench.yaml content

instrument1:
  loader: loader1-name
  parameter1: value1
  parameter2: value2

example_instrument:
  loader: brand-model-loader
  ip: 192.168.0.1
  port: 12345

Purpose

It should contain all the information that is required to instantiate the drivers of an experiment bench. Thus, you should specify there all the connection parameters (IP address, port, baudrate, etc.). You can also add here all the information which is not useful for the experiments. This might include configuration parameters specific to an instrument, credentials, etc.

Bench instrument entries

Each of its mapping entries which contains the loader key represents a bench instrument. The loader values specifies the name of the loader that handles the instrument. Prior to being used by an ExperimentFactory, a suitable loader must have been registered. The other values of the entry are passed to initiate_connection(), in order to initialize the loader.

A bench might have multiple instruments handled by the same loader(eg. there might be multiple motors, which are similarly driven in software but act on different elements). In order to allow the user to differentiate them, you can add arbitrary attributes to the entry, which will be ignored by the loader. For example, you might specify the element that is moved by a motor, the wavelength of a light, etc.

Arbitrary attributes for filtering

You can also add top-level entries which are not mappings, or miss the loader key. They are simply ignored by phileas. It is a good idea to use them to document the experiment setup.

Bench-only instruments

In some situations, it might be useful to have instruments that will never be required in the experiment configuration file. They are called bench-only instruments.

Let’s say that a remote computer provides access to different instruments. You can access it through an SSH connection. You could then use the following configuration:

Bench-only instruments example

# Bench-only instrument
control-computer:
  loader: ssh-loader
  user: user-name
  password: password-value

instrument:
  loader: remote-instrument
  control: control-computer  # Internal reference
  parameter: value

control-computer is only used to establish the connection to instrument, which can reference it with control: control-computer. The remote-instrument loader internally uses get_bench_instrument() to get the control-computer instance.

Template generation

A bench template file can be generated automatically by phileas. See python -m phileas generate bench -h for the available options.