MDF Reader Byte Vector Output

Hello KNIMErs,

I want to create a workflow, where I can read .mf4 files with the MDF Reader.
At the moment, I am able to read .mf4 files, but have problems with the output.

Some Signals like in the screenshot are displayed as Byte Vectors.
image

In The ASAM-Wiki ( ASAM MDF - Wiki), I found the following sentence: “For complex data types currently there are no conversion rules defined. “Byte Array” type is the most general complex data type because it allows storing any kind of data “blob” as signal value.”

Does this mean, that with the MDF-Reader Node and the asammdf library, I am not able to decode these Signal or does anybody know a workaround?

Sincerely Flo1124

Hi @Flo1124 and welcome to the forum.

Let me see if I can contact one of the developers involved with the MDF Reader and see if they can help.

Hi @ScottF,

thanks for your help.
Maybe another question, that could help me with the MDF Reader:
Is it possible, that I can use another library than asammdf?

Sincerely
Flo1124

You can use a Python Script Node and use a python script to read the mdf files there.

Hi @Flo1124,

Just to point this out: The ASAM Wiki you refer to is a website associated with the ASAM MDF standard itself, not the asammdf library that we use in our node. I.e., this is a limitation on the standard’s side, so using a different tool will probably present the same challenge of having to convert the data yourself.

That being said, the MDF Reader node does currently not offer all features of the asammdf library and is also based on a quite dated version of the library (v5.19.14, while the most recent one is v7.3.0), so using asammdf directly via a Python Script node (potentially installing a more recent version beforehand) might give you some more options at the moment.

I hope this was somewhat helpful. Otherwise, I would probably need some more information about your use case, e.g. what type of data is encoded in these channels that are currently returned as bytes. Is it text?

Marcel

3 Likes

Thanks for your reply,
I have no clue about Python coding, but I will try my best with the Python Script Node.

Greetings Flo

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