The controller tried to read the response before the instrument finished processing the request. Buffer Mismanagement:
While not always required (some APIs auto-append it), many SQL shells require a semicolon to execute. Add ; at the very end of your query and test again. 420 query unterminated
: The instrument might still be processing a command and hasn't placed data in the output queue yet, or a previous read already emptied the buffer. The controller tried to read the response before
In simple terms, you asked the instrument "What's the answer?" before you finished asking the actual question. Common causes include: 420 query unterminated