Fluke 9640A Series, Instruction Manual

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SCPI and IEEE Bus Descriptions
What is SCPI?
4B
4B-3
What is SCPI?
SCPI (Standard Commands for Programmable Instruments) is a standardized set of
commands used to remotely control programmable test and measurement instruments.
The instrument firmware contains the SCPI. It defines the syntax and semantics that the
controller must use to communicate with the instrument.
This chapter is an overview of SCPI and shows how SCPI is used in the Instrument.
SCPI is based on IEEE-488.2 to which it owes much of its structure and syntax. SCPI
can, however, be used with any of the standard interfaces, such as GPIB
(IEC625/IEEE 488), VXI and RS-232.
Reason for SCPI
For each instrument function, SCPI defines a specific command set. The advantage of
SCPI is that programming an instrument is only function dependent and no longer
instrument dependent. Several different types of instruments, for example an
oscilloscope, a Instrument and a multimeter, can carry out the same function, such as
frequency measurement. If these instruments are SCPI compatible, you can use the same
commands to measure the frequency on all three instruments, although there may be
differences in accuracy, resolution, speed, etc.
Compatibility
SCPI provides two types of compatibility, vertical and horizontal.
Vertical compatibility means that all instruments of the same type have identical controls.
For example, oscilloscopes will have the same controls for timebase, triggers and voltage
settings. See Figure 4B-1.
AC
AC
:INPut:COUPling AC
ead100f.eps
Figure 4B-1. Vertical Compatibility
Horizontal compatibility means that instruments of different types that perform the same
functions have the same commands. For example, a DMM, an oscilloscope, and a source
can all measure frequency with the same commands. See Figure 4B-2.