Protocols; Functional Elements; Protocol Overview - Agilent Technologies Infiniium 90000 Series Programmer's Manual

5
Message Communication and System Functions

Protocols

The message exchange protocols of IEEE 488.2 define the overall scheme
used by the computer and the oscilloscope to communicate. This includes
defining when it is appropriate for devices to talk or listen, and what
happens when the protocol is not followed.
•
•
•
•
•
•

Functional Elements

Before proceeding with the description of the protocol, you should
understand a few system components, as described here.
Input Buffer
The input buffer of the oscilloscope is the memory area where commands
and queries are stored prior to being parsed and executed. It allows a
computer to send a string of commands, which could take some time to
execute, to the oscilloscope, then proceed to talk to another oscilloscope
while the first oscilloscope is parsing and executing commands.
Output Queue
The output queue of the oscilloscope is the memory area where all output
data or response messages are stored until read by the computer.
Parser The oscilloscope's parser is the component that interprets the commands
sent to the oscilloscope and decides what actions should be taken.
"Parsing" refers to the action taken by the parser to achieve this goal.
Parsing and execution of commands begins when either the oscilloscope
recognizes a program message terminator, or the input buffer becomes full.
If you want to send a long sequence of commands to be executed, then
talk to another oscilloscope while they are executing, you should send all
of the commands before sending the program message terminator.

Protocol Overview

The oscilloscope and computer communicate using program messages and
response messages. These messages serve as the containers into which sets
of program commands or oscilloscope responses are placed.
A program message is sent by the computer to the oscilloscope, and a
response message is sent from the oscilloscope to the computer in
response to a query message. A query message is defined as being a
program message that contains one or more queries. The oscilloscope will
100
"Functional Elements"
"Protocol Overview"
"Protocol Operation"
"Protocol Exceptions"
"Suffix Multiplier" on page 101
"Suffix Unit" on page 102
Agilent Infiniium 90000 Series Oscilloscopes Programmer's Reference
on page 100
on page 100
on page 101
on page 101