App 2-4
Appendix 2. Communication Commands
IM CW120-E
1.2
Commands
Commands
There are two types of command (program
header) that can be sent from the personal
computer to the CW120. They differ in the
format of their program headers.
Common Command Header
Commands defined in IEEE 488.2-1987 are
called common commands. The header format
of a common command is shown below. An
asterisk (*) always precedes a common
command.
*<Mnemonic>?
*<Mnemonic>
Compound Header
Commands other than common commands,
that are dedicated to the CW120, are classified
and arranged in a hierarchy according to their
functions. The format of a compound header is
shown below. A colon (:) is used to specify a
lower-level header.
:<mnemonic>: <mnemonic>: ... :<mnemonic>?
:<mnemonic>: <mnemonic>: ... :<mnemonic>
Simple Header
A simple header is a functionally independent
command with no hierarchical structure. The
format of a simple header is shown below.
:<mnemonic>?
:<mnemonic>
When Concatenating Commands
●
Command Group
A group of commands which share the same
compound header is called a command group.
A command group may contain sub-groups.
Example: Command group relating to electric
energy measurement
INTEgrate?
INTEgrate:STARt:TIME
INTEgrate:STOP:TIME
INTEgrate:STORe?
●
When Concatenating Commands of the
Same Group
The CW120 stores information on which
hierarchical level the command currently being
executed belongs to, and performs analysis on
the assumption that the next command will also
belong to the same level. Therefore, you may
omit the header of the next command if the two
commands belong to the same group.
Example: INTEgrate:STORe:FILE FILE0;STARt:
TIME 1999,1,1,0,0<PMT>
●
When Concatenating Commands of
Different Groups
Include a colon (:) before the header, if the
following command does not belong to the
same group as the preceding command.
Example: SYSTem:CURRent:AUTO ON;
:INTEgrate:START:EXECute<PMT>
●
When Concatenating Common
Commands
Common commands defined in IEEE 488.2-
1987 are independent of hierarchy. A colon (:)
is not necessary before a common command.
Example: INTEgrate:STORe:FILE FILE0;*CLS;
STARt:TIME 1999,1,1,0,0<PMT>
●
When Separating Commands with
<PMT>
If a terminator is used to separate two
commands, each command is a separate
message. Specify the command header for
each command even when the commands from
the same command group are being
concatenated.