Program Message Terminator - HP 54501A Programming Reference Manual

Program Message
Terminator
Character Program Data. Character program data
is
used to convey
parameter information
as
alpha or alphanumeric strings.
For example,
the timebase command
MODE
can be
set
to auto, trigger, or single.
The
character program data
in this case may be
AUTO, TRIGGER,
or
SINGLE. :TIMEBASE:MODE SINGLE
sets
the timebase mode to
single.
Numeric Program Data. Some command headers require program data
to be
a number.
For
example,
:TIMEBASE:RANGE
requires the desired
full
scale
range to be
expressed numerically.
The instrument recognizes
integers,
real
numbers, and scientific notation. For more information
see
the chapter "Message Communication
and System
Functions."
The program codes within
a
data
message
are executed
after
the
program
message
terminator
is
received.
The terminator
may be either an
NL
(New Line)
character, an
EOI
(End-Or-Identify)
asserted, or a
combination of the
two.
All
three ways are equivalent with the
exact
encodings for the program terminators listed in the chapter "Message
Communication
and System Functions." Asserting the
EOI
sets
the
EOI
control line low on the
last
byte of the data
message.
The
NL
character
is
an
ASCII
linefeed (decimal 10).
Note
The
NL
(New Line)
terminator
has the
same function
as
an
EOS (End Of
String) and
EOT (End
Of
Text) terminator.
HP 54501
A
Programming
Introduction to Programming an Oscilloscope
1-9