14-3
IM 253421-01E
Communication Commands 2 (System of Commands Complying to the IEEE 488.2-1987 Standard)
14
14.2 Program Format
14.2.2 Messages
Blocks of message data are transferred between the
controller and this instrument during communications.
Messages sent from the controller to this instrument
are called program messages, and messages sent
back from this instrument to the controller are called
response messages.
If a program message contains a query command, i.e.
a command which requests a response, this
instrument returns a response message. A single
response message is always returned in reply to a
program message.
Program Messages
As explained above, the data (message) sent from the
controller to this instrument is called a program
message. The format of a program message is shown
below.
<PMT>
;
Program message unit
<Program message unit>
A program message consists of one or more program
message units; each unit corresponds to one
command. This instrument executes commbìts one
by one according to the order in which they are
received.
Program message units are delimited by a “;”.
For a description of the format of the program
message unit, see the explanation given further below.
Example
Unit
Unit
:CONFIGURE:MODE RMS;FILTER ON<PMT>
<PMT>
PMT is a terminator used to terminate each program
message. The following three types of terminator are
available.
NL (New Line): Same as LF (Line Feed). ASCII code
“0AH” is used.
^END: END message defined in IEEE488.1. (EOI
signal)
(The data byte sent with an END message will be the
final item of the program message unit.)
NL^END: NL with an END message attached
(NL is not included in the program message unit.)
14.2.1 Symbols Used in Syntax
Descriptions
Symbols which are used in the syntax descriptions in
section 14.3 are shown below. These symbols are
referred to as BNF notation (Backus-Naur Form). For
detailed information, see pages 14-7 and 14-8.
Symbol
Description
Example
Example
< >
Defined value
DISPLAY<x> <x>=1, 2
DISPLAY2
{}
One of the options in
MODE {RMS|VMEan|DC}
MODE RMS
{} is selected.
|
Exclusive OR
MODE {RMS|VMEan|DC}
MODE RMS
[ ]
Abbreviated
SCALing[:STATe] {<Boolean>}
...
may be repeated