HP 54501A Programming Reference Manual page 51

<
program
message >.
The
<
program message >
is
a
complete
message
to be
sent
to the instrument.
The
instrument
will begin executing
commands once it
has
a
complete
< program message
>,
or when the
input buffer
becomes full.
The
parser
is also
repositioned to the root
of
the
command tree
after executing
a
complete
< program message
>.
Refer
to the
Tree Traversal
Rules in the Programming and
Documentation Conventions chapter for more details.
Figure
3-3.
<program
message
>
<
program message
unit
>.
The
<
program
message unit
>
is
the
container for individual commands within
a
<
program message
>.
<commond messoge
unil>
<query messoge
unit>
Figure
3-4.
<program
message
unit >
HP 54501A
Programming
Message Communication and System Functions
3-9