Parsing oscilloscope data, follow up
In general it looks good to me; only small nits:

You want to move from asserts to throwing proper, informative exceptions - for instance, showing both expected and actual values.

At the end of if name != ":CURVE":, you can just issue a continue instead of an else block - helps with the indentation.

Instead of making chunk a list and then doing a join at the end, you can make it a string and do string appending.