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Programming
Response generation
Response generation
As defined by IEEE 488.2, query responses may be buffered for the following
conditions:
• When the query is parsed by the instrument.
• When the controller addresses the instrument to talk so that it may read the
response.
The responses to a query are buffered when the query is parsed.
Command headers immediately followed by a question mark (?) are queries.
Query commands are used to find out information regarding the instrument's
current state. After receiving a query, the instrument interrogates the
requested function and places the answer in its output queue. The answer
remains in the output queue until it is read or another command is issued.
When read, the answer is transmitted across the bus to the designated listener
(typically a controller).
The output queue must be read before the next program message is sent. For
example, when you send the query :SYSTEM:CONFIG? you must follow that
query with an input statement. In HP BASIC, this is usually done with an
ENTER statement immediately followed by a variable name. This statement
reads the result of the query and places the result in a specified variable.
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