Editing GPIB (section)

== History ==
In the 1960s, [[Hewlett-Packard]] (HP) manufactured various automated test and measurement instruments, such as digital [[multimeter]]s and [[logic analyzer]]s. They developed the ''HP Interface Bus (HP-IB)'' to enable easier interconnection between instruments and controllers (computers and other instruments).<ref>{{cite journal |first=Gerald E. |last=Nelson |first2=David W. |last2=Ricci |title=A Practical Interface System for Electronic Instruments |journal=Hewlett-Packard Journal |volume=24 |issue=2 |pages=2–7 |date=October 1972 |url=http://hparchive.com/Journals/HPJ-1972-10.pdf |quote=Controllers: 3260A Marked Card Reader; [[HP 9800 series#Second generation|9820A]] Calculator (with 11144A Interface Kit) }}<br/>{{cite journal |first=Donald C. |last=Loughry |title=A Common Digital Interface for Programmable Instruments: The Evolution of a System |journal=Hewlett-Packard Journal |volume=24 |issue=2 |pages=8–11 |date=October 1972 |url=http://hparchive.com/Journals/HPJ-1972-10.pdf}}</ref> This part of HP was later (c. 1999) spun off as [[Agilent Technologies]], and in 2014 Agilent's test and measurement division was spun off as [[Keysight Technologies]].{{cn|date=January 2024}}

The bus was relatively easy to implement using the technology at the time, using a simple parallel [[Bus (computing)|bus]] and several individual control lines. For example, the HP 59501 Power Supply Programmer and HP 59306A Relay Actuator were both relatively simple HP-IB peripherals implemented in [[Transistor–transistor logic|TTL]], without the need for a microprocessor.

HP licensed the HP-IB patents for a nominal fee to other manufacturers. It became known as the General Purpose Interface Bus (GPIB), and became a [[de facto standard]] for automated and industrial instrument control. As GPIB became popular, it was formalized by various [[standards organization]]s.

In 1975, the [[Institute of Electrical and Electronics Engineers|IEEE]] standardized the bus as ''Standard Digital Interface for Programmable Instrumentation'', IEEE 488; it was revised in 1978 (producing IEEE 488-1978).<ref>{{Citation |title=IEEE Standard Digital Interface for Programmable Instrumentation |publisher=[[Institute of Electrical and Electronics Engineers]] |year=1978 |id=ANSI/IEEE Std 488-1978 |isbn=978-1-5044-0366-5 |doi=10.1109/IEEESTD.1978.7425098}}<br>{{Citation |title=IEEE Standard Digital Interface for Programmable Instrumentation |publisher=[[Institute of Electrical and Electronics Engineers]] |year=1987 |id=ANSI/IEEE Std 488.1-1987 |isbn=0-471-62222-2 <!-- This is the ISBN on the document --> }}, p. iii</ref> The standard was revised in 1987, and redesignated as IEEE 488.1 (IEEE 488.1-1987). These standards formalized the mechanical, electrical, and basic protocol parameters of GPIB, but said nothing about the format of commands or data.

In 1987, IEEE introduced ''Standard Codes, Formats, Protocols, and Common Commands'', IEEE 488.2. It was revised in 1992.<ref>{{Citation |title=IEEE Standard Codes, Formats, Protocols, and Common Commands for Use With IEEE Std 488.1-1987, IEEE Standard Digital Interface for Programmable Instrumentation |publisher=[[Institute of Electrical and Electronics Engineers]] |year=1992 |id=IEEE Std 488.2-1992 |isbn=978-1-55937-238-1 }}</ref> IEEE 488.2 provided for basic syntax and format conventions, as well as device-independent commands, data structures, error protocols, and the like. IEEE 488.2 built on IEEE 488.1 without superseding it; equipment can conform to IEEE 488.1 without following IEEE 488.2.

While IEEE 488.1 defined the hardware and IEEE 488.2 defined the protocol, there was still no standard for instrument-specific commands. Commands to control the same class of instrument, ''e.g.'', multimeters, varied between manufacturers and even models.

The United States Air Force,<ref>Project Mate in 1985</ref> and later Hewlett-Packard, recognized this as a problem. In 1989, HP developed their Test Measurement Language (TML)<ref>{{cite web | title = GPIB 101, A Tutorial of the GPIB Bus | publisher = ICS Electronics | url = http://www.icselect.com/ab_note.html#anchor338658 | page=5, paragraph = SCPI Commands }}</ref> or Test and Measurement Systems Language (TMSL)<ref>{{cite web | title = Hewlett Packard Test & Measurement Catalog 1991 | publisher = hparchive.com | url = http://hparchive.com/Catalogs/HP-Catalog-1991.pdf | page=8, paragraph = SCPI }}</ref> which was the forerunner to [[Standard Commands for Programmable Instrumentation]] (SCPI), introduced as an industry standard in 1990.<ref>{{cite web | title = History of GPIB | publisher = National Instruments | url = http://zone.ni.com/devzone/cda/tut/p/id/3419 | quote = In 1990, the IEEE 488.2 specification included the Standard Commands for Programmable Instrumentation (SCPI) document. | access-date = 2010-02-06 }}</ref> SCPI added standard generic commands, and a series of instrument classes with corresponding class-specific commands. SCPI mandated the IEEE 488.2 syntax, but allowed other (non-IEEE 488.1) physical transports.

The [[International Electrotechnical Commission|IEC]] developed their own standards in parallel with the IEEE, with IEC 60625-1 and IEC 60625-2 (IEC 625), later replaced by [[IEC 60884|IEC 60488-2]].

[[National Instruments]] introduced a backward-compatible extension to IEEE 488.1, originally known as HS-488. It increased the maximum data rate to 8 [[megabyte|Mbyte]]/s, although the rate decreases as more devices are connected to the bus. This was incorporated into the standard in 2003 (IEEE 488.1-2003),<ref>{{Cite web | title = Upgraded Standard Boosts Speed of IEEE 488 Instrument Buses Eightfold | date = 2003-10-06 | publisher = IEEE | url = http://standards.ieee.org/announcements/pr_4881upgrade.html | archive-url = https://web.archive.org/web/20031207052849/http://standards.ieee.org/announcements/pr_4881upgrade.html | url-status = dead | archive-date = December 7, 2003 | access-date = 2010-02-06 }}</ref> over HP's objections.<ref>{{Cite press release|title=HP and Other Test and Measurement Companies Urge IEEE to Oppose Revisions of Established IEEE 488 Standard |publisher=Hewlett-Packard Company |date=December 1997 |url=http://grouper.ieee.org/groups/imstc8/488/1/hppress12-97.html |access-date=2010-02-16 |url-status=dead |archive-url=https://web.archive.org/web/20110610164221/http://grouper.ieee.org/groups/imstc8/488/1/hppress12-97.html |archive-date=2011-06-10}}</ref><ref>{{cite web|title=P488.1 Project Home |publisher=IEEE |url=http://grouper.ieee.org/groups/imstc8/488/1/ |access-date=2010-02-16 |url-status=dead |archive-url=https://web.archive.org/web/20100428090906/http://grouper.ieee.org/groups/imstc8/488/1/ |archive-date=2010-04-28}}</ref>

In 2004, the IEEE and IEC combined their respective standards into a "Dual Logo" IEEE/IEC standard IEC 60488-1, ''Standard for Higher Performance Protocol for the Standard Digital Interface for Programmable Instrumentation - Part 1: General'',<ref>{{cite book | title = IEC/IEEE Standard for Higher Performance Protocol for the Standard Digital Interface for Programmable Instrumentation - Part 1: General (Adoption of IEEE Std 488.1-2003) | publisher = IEEE | doi = 10.1109/IEEESTD.2004.95749 | isbn = 978-0-7381-4536-5 }}</ref> replaces IEEE 488.1/IEC 60625-1, and IEC 60488-2,''Part 2: Codes, Formats, Protocols and Common Commands'',<ref>{{cite book | title = Standard Digital Interface for Programmable Instrumentation- Part 2: Codes, Formats, Protocols and Common Commands (Adoption of (IEEE Std 488.2-1992) | publisher = IEEE | doi = 10.1109/IEEESTD.2004.95390 | hdl = 11059/14380 | isbn = 978-0-7381-4100-8 }}</ref> replaces IEEE 488.2/IEC 60625-2.<ref>{{cite web | title = Replaced or Withdrawn Publications | url = http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?header=IEC&search=replaced&wwwprog=sea22.p | publisher = IEC | access-date = 2010-02-06 | url-status = dead | archive-url = https://archive.today/20120417191411/http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?header=IEC&search=replaced&wwwprog=sea22.p | archive-date = 2012-04-17 }}</ref>