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The Messinstrumente program can address one or more instruments that are connected to the PC via a USB interface. The instruments must belong to the USB class 'Test and Measurement' as well as to the subclass USB488. Windows does not offer driver support for USBTMC devices, but you can use the existing WinUSB driver. The program uses the libusb-1.0 library to access the instruments, which in turn communicates with the installed WinUSB driver.
The program should make it possible to control several instruments simultaneously, to read in, evaluate and display data and to save them automatically. In order to be able to address instruments from different manufacturers, there are configuration files. The program can create and edit these files as soon as an instrument is opened.
I use the program with instruments from Rohde & Schwarz, Rigol, Picotest and with self-programmed PIC18F microcontrollers. I don't own any other USBTMC devices, and can only guess and hope that it will work with other instruments as well.
The program can be copied into any directory, no installation is necessary or planned. To be able to save settings, write permissions are required in this directory. It is not written into the registry or stored anywhere else unsolicited data. An internet connection is not necessary, the program does not access the network.
The WinUSB driver must be installed for each instrument used. Normally a suitable '.inf' file is sufficient for the installation. Because of the different Windows versions and the obligation of the driver signature, it is easiest to use the open source program Zadig. There are separate versions for Windows XP, and a version for newer Windows versions. 32- and 64-bit systems are supported. The website with the download links and description is: https://zadig.akeo.ie/
If the driver is correctly installed, the instrument will appear in the Device Manager. Here is an example of Windows 7:
The program opens with an empty MDI frame window. MDI stands for 'Multiple Document Interface', and is an old method to manage multiple documents or content in one frame window. You can open another MDI frame window in the 'File' menu at any time. With the exception of the selection window for the instruments, all other windows can also be opened separately. If the CTRL key is pressed during opening, or the corresponding menu item or button is pressed. There is also an option in the 'Window' menu to always open the windows separately.
The user interface of the program is displayed in German or English. Via the menu 'File'->'Preferences...' the language can be changed in the settings. The changes become effective only after a restart of the program.
When closing the program, all open windows will be notified individually so that they close. If the program cannot be closed, you can force it to be closed by pressing the CTRL key while the menu item 'File'->'Exit' is pressed.
With the menu 'Instrument'->'Select...' the window with the available instruments opens. Only USBTMC instruments with installed WinUSB drivers are displayed, and only instruments that have not yet been opened. If, for example, an instrument is opened with a double-click, it disappears from the displayed list. After closing or disconnecting the instrument, it reappears in the list.
The window with the instrument can be opened as an MDI window or separately. Either the CTRL key is pressed while opening, or the menu item 'Connect in separate window' or the corresponding button in the toolbar is pressed. The separate window remains connected to the MDI frame window and this must remain open. If the MDI frame window is closed, all connected windows will also be closed.
If a configuration file exists for the instrument, it is displayed in the first module 'Instrument' under 'Configuration:'. If a configuration is available, the 'Screenshot' module can be used, for example, or SCPI commands can be sent.
The 'Configuration' module can be used to create a new configuration for the instrument.
The file name is predefined and consists of the manufacturer and model name, which are determined by the SCPI command '*IDN?'. The 'Create' button saves the configuration file in the 'Instrument' program directory. With the button 'Copy from...' an existing configuration file can be used as a template. After creating and changing the configuration, the instrument must be reconnected, only then will all changes take effect.
In the group 'Instrument' there is the entry 'Configuration'. Another configuration file can be selected there. This means that only one configuration file needs to be changed for a model group. For example, the Rigol oscilloscopes of the DS1000Z series use their own configuration for each model, but all refer to the file 'rigol_technologies_ds1000z.ini'.
If a setting exists in both configurations, the one directly used by the instrument will always be used. Thus, settings for one model can be changed, but the other settings can be used by the second configuration.
For the different functions of the instruments, their control, etc., there are windows and modules, or modules with functions. As window there is the 'Instrument' itself, and e.g. the 'SCPI command' or the 'Information'. A window is always connected to the selected instrument, but can also be used partially in a disconnected state, e.g. to edit settings.
Modules only exist in the 'Instrument' window. Which modules are present is set in the respective configuration file of the opened instrument, with the exception of the 'Instrument' and 'Configuration' modules. At the moment there is only the additional module 'Screen copy' to retrieve and save screen copies of the instrument individually or automatically.
With this module, screen copies can be retrieved from the instrument. Either individually or automatically at any time interval. The selection of Single or Automatic can be made via the function list on the left.
The functions themselves, or controls that are displayed, can be changed in the configuration. With the module 'Screen copy' it is the module itself, 'ModuleScreencopy'->'ModuleEnabled', and the options 'Stop/Run' and 'LocalMode'. The operation of the module should be self-explanatory. Tooltips are displayed for further help with some controls when the mouse pointer is pointing at them and a short wait is performed.
With this module the curve data can be retrieved from the instrument. Either individually or automatically at any time interval. The selection of Single or Automatic, can be done by using the function list on the left side. The screen data and the memory data can be read in. The data can be saved as CSV or binary file.
With this module recorded curve data can be retrieved from the instrument. Either individually or automatically in any increments. The selection of Single or Automatic, can be done by using the function list on the left side. The screen data and the memory data can be read in. The data can be saved as CSV or binary file.
The format CSV and BIN has been extended with the number of the recording. In CSV format there is the entry 'Record Frame' in the header line.
In BIN format, the data is stored as it is received with ':WAV:DATA?;:WAV:PRE?;:FUNC:WREP:FCUR?'. However, the position of the individual samples is aligned with the baseline. The stored sample is calculated with 'Sample - (Yreference + Yorigin)'. The preamble values are stored unchanged. With Yreference and Yorigin you could calculate back to the original position. If no recordings are saved, the number of the recording is not saved either.
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