The Command Tree; Command Types - HP 54501A Programming Reference Manual

The Command
Tree
The
command tree
(figure 4-1)
shows all commands
in the
HP 54501A
and the relationship
of the commands to each other. The
IEEE
488.2
common commands are not listed
as
part of the
command tree since they
do not affect the position of
the parser within the tree.
After
a
<
NL
>
(linefeed
-
ASCII
decimal
10)
has been
sent
to the instrument, the parser
will be
set
to the "root"
of the command tree.
Command Types
The
commands for
this instrument can be placed into three types.
The
three types are:
Common commands. Common commands are independent of the
tree,
and do not affect the position of the parser within the tree. These differ
from root level commands in that root level
commands place the parser
back at the root.
Example: »RST.
Root Level commands. The root level commands
reside at the
root of the
command tree. These commands are always parsable if they occur
at
the
beginning
of
a program message,
or are preceded by
a colon.
Example: :AUTOSCALE
Subsystem commands. Subsystem commands are grouped together
under
a
common node
of the tree, such
as
the
TIMEBASE
commands.
Programming and Documentation Conventions
4-4
HP 54501A
Programming