I would like to know how to handle ASN.1 encoding/decoding in LabView?

[J_Bangasser]

I would like to know how to handle ASN.1 encoding/decoding in LabView?

[GerdW · Accepted solution]

Hi J,

from the example given here it looks like a simple bytestream format...

You have to read the byte stream, get the first and second byte to decode the datatype and length and then read&typecast the according number of bytes. Then again reading 2 bytes and so on...

Encoding will work the same but in reverse order

[Munna232]

Hi all,

I want to read TLV (ASN.1) format files with Labview and extarct the data from it.

Please help me if anyone knows any information about this.

Thanks & Regards,

Guru

[GerdW]

Hi Guru,

did you even read the linked article? It's quiet easy to decode the data once you know the code table...

[daveTW]

It seems like a homework, huh

[Munna232]

Hello GerdW,

Thank you so much for your reply.

I read that article (i.e. ASN.1 Str) but I don't know how to read my file for decoding.

I don't know the code table present in my file.

Please provide me sample VI.

Thanks & Regards,

Guru

[GerdW]

Hi Guru,

- use ReadBinaryFile to read the ASN file as a bytestream.

- Try to find more documentation about ASN specification. I don't use such files nor do I have any intention to do your work (and so I don't have any VIs). You will need such a document to fully understand the file format...

It's your task, so do your work. It's a perfect example to learn to use file read functions and type conversions...

[Munna232]

Dear GerdW,

Thank you so much for your support and advice 🙂

I don't have any document for this file format.

Just I know that its TLV (ASN.1 with PER/BER str inside)format .

I guess ASN.1 standard format. I don't know how can I get the TLV (Tag length value) for every signal present in that file.

BR,

Guru

[GerdW]

Hi guru,

as said before:

- Use FileRead function to read the tag (byte) and the length (byte).

- Then read the value bytes (given by length) and parse it (information given by tag).

- Then continue with reading next tag and length...

Simplified example:

[Munna232]

Dear GerdW,

Thank you so much for sharing sample VI.

I checked your VI with my sample file But, I'm not getting proper data.

I want to read CAN Frame (i.e. Timestamp ID and Payload) data from this file.

Thanks & Regards,

Guru