Tom Burke has had enough with GPIB, calling it as finicky as the ISA bus. Do you agree, or should GPIB continue its long life?
Our illustrious test and measurement editor, hiding behind the name MeasurementBlues, dared to write an article on GPIB and how it is still supported and still hasn't died. Well, I'm here to advocate for GPIB's death, once and for all.
Some of you are likely new to the T&M world and don't know much about GPIB, so I'll give a quick overview. GPIB had its beginnings a long, long time ago (in the late 1960s) as the Hewlett-Packard Interface Bus (HP-IB). In 1975, the IEEE standardized the bus to IEEE-488.1, General Purpose Interface Bus (GPIB).
As a young man (left), Joe Keithley made measurements one at a time and write them on paper. Years later (right), Keithley recorded measurements through buses such as GPIB. To see the full October 1992 cover of Test & Measurement World, click here.
GPIB connects multiple pieces of test equipment to a computer, allowing remote control and data acquisition. It was, at one time, a great boon to the test world. We no longer required someone to go around, perform individual measurements, and then write them down (hopefully neatly), and then have someone else put them all into some usable format.
GPIB connector pinout.
(Source: National Instruments)
Individual instruments are connected by a series of cables. In theory, you could have up to 15 devices (31 if you use an extender) in either a linear or forked arrangement. This was made possible by the connectors.
Each connector has eight bidirectional I/O lines and a few handshaking signals (see diagram). The cables are approximately ½ inch or so in diameter.
It seems pretty good, doesnít it? Even I admit it. And when there was nothing better, it was pretty sweet. But then reality set in, and all the way things work that ain't the way they're supposed to showed up. Let's take these pitfalls in small steps.
To Page 2: GPIB is a pain