Table of Contents
Advertisement
Chapter 3 Program Syntax and Programming
3.1 Messages
Message
Messages are used to exchange information between
the controller and the instrument. Messages that are
sent from the controller to the instrument are called
program messages and messages that are sent back
from the instrument to the controller are called
response messages.
If a program message contains a message unit that
requests a response (a query), the instrument returns
a response message upon receiving the program
message. A single response message is always
returned in response to a single program message.
Program Message
Data that is sent from the controller to the instrument
are called program messages. The program message
format is shown below.
;
<Program message unit>
<Program Message Unit>
A program message consists of one or more program
message units; each unit corresponds to one
command. The instrument executes the received
commands in order.
Each program message unit is separated by a
semicolon (;).
For details regarding the format of the program
message unit, see the next section.
Example
:MEASURE:MODE HHISTOGRAM;FUNCTION PERIOD,A<PMT>
Unit
IM 704510-17E
<PMT>
PMT is a program message terminator. The following
three types are available.
NL (New Line):
^END:
NL^END:
• Program Message Unit Format
The program message unit format is shown below.
<Program header>
<PMT>
<Program header>
The program header indicates the command type. For
details, see page 3-3.
<Program Data>
If certain conditions are required in executing a
command, program data is added. A space (ASCII
code "20H") separates the program data from the
header. If there are multiple sets of program data, they
are separated by commas (,).
For details, see page 3-5.
Example
Unit
Same as LF (Line Feed). ASCII
code "0AH"
END message that is defined in
IEEE488.1 (EOI signal)
(The data byte that is sent
simultaneously with the END
message is the last data of the
program message.)
NL with an END message added
(NL is not included in the program
message.)
Space
<Program data>
:SAMPLE:GATE:MODE EVENT<PMT>
Data
Header
3.1 Messages
3
,
3-1
Advertisement
Table of Contents
