SCPI Simulation

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Greetings- just getting our feet wet in OpenTap and OpenPath. In developing a test step that executes a very simple command to an SCPI-enabled instrument/device:

  1. Is the machine that is running the test plan required to have any other special drivers or libraries other than ‘just’ VStudio, OpenTap SDK, and PathWave? For example, if our test step just sends a very simple SCPI command to a Keysight specAn, does the machine running the test step need any other drivers?

  2. We like to keep our code base running through a CI/CD pipeline and most of our projects use simulators to act as sinks for our targets (those projects are mostly REST projects and developing a simple server to run locally during testing is easy). Is there a way or is there an SCPI project that sets itself up as an SCPI sink? I found this: GitHub - coburnw/python-vxi11-server: A VXI-11 Instrument Server written in Python, which can act as a VX11 server, but has anyone run across such a thing for simulating SCPI end points?
    Thanks

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Hi @mescgroup,

  1. In order to use the ScpiInstrument class you just need some libvisa32 implementation. I recommend installing the Keysight IO Libraries, but anything will do on both Windows and Linux.

  2. I haven’t thought about setting up a VX11 sink, that is a great idea! From a code perspective you can replace the IO-part of the ScpiInstrument, with a mock interface implementation, but setting up a VXI-11 sink in a docker container sounds more awesome if you ask me! I haven’t heard about anything like this though.

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  1. Thanks, that clears up a lot.
  2. Yah, I wasn’t sure what to do with it, but I was able to run the VXi-11 inside the opentap docker (after installing some dependencies). This shows the client requesting the time from the server (a time device sink) ; both are running inside the container.

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Hi @mescgroup ,

This is a really good concept, I have done simulation of SCPI instruments using some internal tools from my company, but I think what you posted here could be used by anybody.

I am curious, What type of instruments are you interested on simulating?

Carlos Montes

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Oh hi Carlos, this is Robin from the meeting/w TMC actually.
Our SCPI instruments are just Keysight SpecAn/Generator.

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FYI there is a pyvisa-sim github project but it appears that it only works for python-developed scpi apps using py-visa drivers. I don’t think you’d be able to run it stand-alone (say, within a docker container or VM) and be able to hit it from a non-python visa app.

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