Tektronix 2714, Programmer'S Manual

Page: 42 / 308

Instrument-Specific Message Structure
2–2
2714 & 2715 Programmer Manual
John’s response may resemble this one:
Mary
$100
Bye bye
He could also respond this way:
Mary
Withdraw Ć $100
Bye bye
These messages are structured in a similar manner. Each contains a salutation
(
John
and
Mary
). Each message consists of one or more message units. For
instance, Mary’s message to John has four units. One of these is a query and is
identified by a question mark (?). Each message unit begins with a “header”
describing what the message is about (such as
dinner
or
cat
). The header is
separated from its object or argument by a dash (–), which is the argument
delimiter. Message units are separated or delimited by semicolons (;).
Each of John’s messages to Mary consist of a single response indicating how
much money she should withdraw. If John thinks Mary will remember her own
question (
withdraw how much?
), he may simply reply “
$100
” as in the first
example. However, to relate his response to her question he may answer
“
Withdraw - $100
” as in the second example. The latter form is equivalent to
receiving a response from the spectrum analyzer when
HDR ON
is selected (see
Command and Query Definitions). Both messages close with a message
terminator “
Bye bye
”.
The instrument-specific messages for the 2714 or 2715 are constructed in a
similar way. The following definitions clarify the structure.
A message unit is a single command, query, or response.
An input message is one or more message units, along with any message unit
delimiters (separators) and a message terminator, transmitted from the controller
to the 2714 or 2715.
An output message is one or more message units, along with any message unit
delimiters (separators) and a message terminator, transmitted from the 2714 or
2715 to the controller.
Message Unit
Input Message
Output Message