Standard Commands for Programmable Instruments: Difference between revisions

Revision as of 13:09, 18 July 2009

Revision as of 14:20, 10 September 2009

Line 1:

The '''Standard Commands for Programmable Instruments (SCPI)''' (often pronounced "skippy") defines a standard set of commands to control programmable test and measurement devices in [[instrumentation]] systems.

The SCPI Standard specifies the [[syntax]]<ref>Standard

The SCPI Standard specifies a [[command structure]] and [[syntax]] for programmable instruments control. The physical communications link, such as [[IEEE-488| GPIB (IEEE-488) ]], [[RS232]], [[USB]], [[VXIbus]] etc, is NOT defined by SCPI. SCPI also includes standard command sets for several classes of instruments, e.g. [[power supply|power supplies]], loads, and measurement devices such as [[voltmeter]]s and [[oscilloscopes]]. A predecessor of SCPI, but with more limited scope, was [[IEEE-488|IEEE 488.2]] in 1987.

Commands for Programmable Instruments (SCPI). Volume 1: Syntax and Style. Version 1999.0. May, 1999.</ref> the [[command structure]]<ref>Standard Commands for Programmable Instruments (SCPI). Volume 2: Command Reference. Version 1999.0. May, 1999.</ref>, and data formats<ref>Standard

Commands for Programmable Instruments (SCPI). Volume 3: Data Interchange Format. Version 1999.0. May, 1999.</ref> for programmable instrument control. The physical communications link, such as [[IEEE-488| GPIB (IEEE-488) ]], [[RS232]], [[USB]], [[VXIbus]] etc, is notdefined by SCPI. SCPI also includes standard command sets for several classes of instruments<ref>Standard

The SCPI Standard specifies a [[command structure]] and [[syntax]]Commands for programmableProgrammable instrumentsInstruments control(SCPI). TheVolume physical4: communicationsInstrument link,Classes. suchVersion as [[IEEE-488| GPIB (IEEE-488)1999.0. ]]May, [[RS232]], [[USB]], [[VXIbus]] etc, is NOT defined by SCPI1999. SCPI also includes standard command sets for several classes of instruments</ref>, e.g. [[power supply|power supplies]], loads, and measurement devices such as [[voltmeter]]s and [[oscilloscopes]]. A predecessor of SCPI, but with more limited scope, was [[IEEE-488|IEEE 488.2]] in 1987.

SCPI commands are [[ASCII]] textual strings, which are sent to the instrument over the physical layer, such as GPIB. Responses to query commands are typically ASCII strings, too. However, for bulk data, such as acquired signal data, binary formats can be used.

Two examples: With the command ''SYSTem:COMMunicate:SERial:BAUD 2400'' the [[Baud| baudrate]] of an RS232 interface can be set to 2400 bit/s. With the command ''SYSTem:COMMunicate:SERial:BAUD?'' the current baudrate of an RS232 interface can be queried. Commands can be abbreviated to their upper case parts, for instance ''SYST:COMM:SER:BAUD?''.

Some instrument manufacturers, notably [[Agilent]], [[Berkeley Nucleonics]] and [[Tektronix]], have implemented SCPI on many new general purpose instruments. Many smaller companies follow their lead. Typically their SCSI implementations roughly follow the spirit of the standard, but don't implement all finer details of the syntax, and don't follow the standard instrument classes commands in detail.

In 2002-2003, the SCPI Consortium voted to become part of the IVI Foundation (Interchangeable Virtual

* Instruments)<ref>[http://www.ivifoundation.org/scpi/default.aspx IVI foundation SCPI page]</ref>.

Instruments). See also [[Virtual Instrument Software Architecture | VISA]]

== See also ==

Instruments). See also* [[Virtual Instrument Software Architecture | VISA]]

==References==

<references />

{{nofootnotes|date=March 2008}}

* [http://www.jpacsoft.com/scpi_explained.htm SCPI explanation from JPA consulting]

* [http://epccs.org/indexes/Software/PyWinGPIB/ Python GPIB to try some SCPI with]

* [http://www.ivifoundation.org/scpi/default.aspx IVI foundation SCPI page]

[[Category:Electronic engineering]]