3. Instruments

Instruments are at the root of every physical measurement. In order for Exopy to be able to work with an instrument, it needs :

  • a driver, which is the layer responsible for transferring the instruction from the program to the instrument and can be written using the VISA protocol or a custom DLL.

  • enough information to open the communication with the instrument (we will call those information the profile of the instrument).

Assuming that somebody wrote the driver for the instrument all you will have to do will be to provide the information needed by the profile. The next sections will explain you how to provide those informations and how Exopy manages them.

3.1. Creating an instrument profile

All informations related to the instruments can be accessed through the ‘Tools/Instruments/Open browser’ menu. This is where you need to go to add profiles.

This will open a dialog holding different tabs :

  • The first one is used to manage the instrument profile and will be discussed in details in this section.

  • The second one displays the current use of the profiles and allow you to track what part of the application is currently using the instruments.

  • The third one simply allows you to check the known drivers.

The first tab holds the list of the known profiles, which is of course empty to begin with. Afterwards selecting a profile will display a summary of the information stored in the profile, which can be edited or deleted using the so named buttons below the summary. To add a profile you should use the ‘Add’ button, which opens another dialog.

A profile contains different pieces of information :

  • an id which allows you to identify the instrument when you need to select it.

  • the model of the instrument this profile corresponds to.

  • the connection information (named connections) which are used to open the connection. This typically contain the ‘address’ of the instrument. Note that you can have multiple valid connections for a single instrument if it supports different protocols (for example a lot of modern VISA-based instrument can be addressed either through USB or TCPIP).

  • the settings which allow you to pass additional parameters to the driver. Specifying settings is fully optional and depends on the architecture of the driver.

First you should fill in the id, and select the model of the instrument. To do so use the ‘Select’ button to open yet another dialog. This dialog presents the the known instruments models as tree where the model are grouped by manufacturer (and serie if the model is part of a serie). To find the model you are looking for more quickly, you can also filter based on the type of instrument (you can for example display only the DC sources). When selecting a model the right panel will display more information such as the drivers that can be used and the allowed connections and settings (note that not all connections and settings apply to all drivers).

Once you have selected the model, you will be able to add connections and settings. You can add at most one connection for each supported connection type (a connection type is considered supported if at least one driver supports it). On the contrary, multiple settings of the same type can co-exist (they must have different names).

When adding a connection or settings, you are first prompted to choose one, and given a brief description of each one. Once added you can select it and provide the expected information.

Note

For VISA connections, you should only have to provide the address as most other fields should be already pre-completed based on the infos provided by the drivers.

You are now done and can add the profile. But before doing so you may want to validate that the information you provided are correct. To do so click on the ‘Validate’ button. A dialog will show. On this dialog, you should select the connection you want to test and if pertinent the driver and settings to use for the test. Once this is done click on ‘Test connection’ (and wait). The result of the operation will be displayed in the field below.

3.2. Use of profiles

The second tab of the dialog allows to know what part of the application is currently using instruments. Note that currently only one part of the application can use instruments at any given time.

Typically when starting a measurement the instruments used in the measurement should go from unused to used by the ‘exopy.measurement’ plugin.