Manual
12
Model 835-M Programmer’s
Manual
V1.1 2011
4.
SCPI
Commands
This chapter provides
an introduction to
SCPI
programming that
includes descriptions
of
the
command
types,
hierarchical command structure,
data
parameters,
and notational conventions. Information on
status system
and trigger
system
programming
is also
provided.
Introduction
Standard Commands
for
Programmable Instruments
(SCPI) is
the new instrument command language for
controlling
instruments
that
goes
beyond
IEEE
488.2 to
address
a wide variety
of
instrument
functions
in a
standard
manner.
SCPI
promotes consistency,
from the
remo
te
programming standpoint, between
instruments
of the
same class
and between instruments
with
the
same
functional capability.
For
a
given
measurement
function
such as
frequency or voltage,
SCPI
defines the
specific command
set that
is
available for that function.
Thus,
two
oscilloscopes
made by different
manufacturers could
be
used
to
make
frequency
measurements in the
same
way. It
is also possible
for a
SCPI
counter to make a
frequency
measurement
using the
same commands as
an
oscilloscope. SCPI commands
are
easy
to learn,
self-explanatory and
account
for both
novice
and expert
programmer’s usage. Once
familiar with the
organization and
structure
of
SCPI, considerable efficiency gains can
be
achieved
during control
program development, independent of the
control
program language selected.
A key to
consistent
programming
is
the
reduction
of multiple ways to control
similar
instrument
functions.
The
philosophy
of
SCPI is
for the
same
instrument
functions
to be controlled by
the
same SCPI
commands.
To
simplify
learning,
SCPI uses
industry-standard
name
s
and terms
that
are
manufacturer
and
customer
supported.
The advantage of
SCPI
for the
ATE system
programmer
is reducing
the time learning how
to
program new
SCPI
instruments
after programming their first
SCPI
instrument.
Programmer
s
who
use
programming
language
s
such as BASIC, C, FORTRAN,
etc., to send instrument
commands
to
instruments
will benefit from
SCPI.
Also, programmers
who
implement instrument
device drivers
for
ATE
program
generators
and/or
s
o
ftware
instrument front
panels
will benefit by
SCPI’s
advantages.
SCPI
defines instrument
commands,
parameters, data, and
status.
It
is
not an
application
package,
programming language or software
int
ended
for instrument front panel
control.
SCPI is designed
to be layered on top of the hardware-independent portion of
IEEE
488.2.