In order to use GPIB, USBTMC, or TCPIP, you need to install a visa runtime. This runtime consists of a visa library (typically visa.dll or similar) that will be used to handle the communication with your instruments.
There exist different vendors that have their own runtimes, e.g.
- National instruments NI-488.2 runtime e.g. version 17.6 can be installed with the file NI4882_176.zip that can be obtained here: http://www.ni.com/de-de/support/downloads/drivers/download.ni-488-2.html
- Tektronix/Keithley 488.2 runtime. Please find further information here: https://de.tek.com/keithley-accessories/test-fixtures-manual/models-kpci-488lpa-and-kusb-488b-reference-manual
- Keysight IO Libraries 18.1.22x 32-Bit Keysight VISA https://www.keysight.com/en/pd-1985909/io-libraries-suite?nid=-33330.977662.00&cc=DE&lc=ger&cmpid=zzfindiosuite
If additional hardware is used, e.g. GPIB adapters, it is recommended to stay with one vendor.
Still, it is also possible to install the runtimes of two vendors side-by-side, e.g. as described here.
- To check whether SweepMe! was able to find a runtime, go to the menu 'Ports' -> 'Port manager'. If there are no error message, everything is alright.
- SweepMe! is based on python 3.6.8 (32bit) and the library of the visa runtime must have the same 'bitness'.
- If the visy library (e.g. 'visa.dll') has not been found, but your are sure that the right file is installed, you can change the path that is used to load the runtime (see below)
- Try to use python 3.6 (32 bit) and pyvisa to see whether it is possible to load the correct visa library: Link
Individual runtime path
SweepMe! loads the visa library during the program start. If your visa library is not found, you can add an individual path. As SweepMe! relies on the library pyvisa, you can use the following link link that describes how to create a configuration file '.pyvisarc' where the path to the visa runtime is given.