Almost all of the data acquisition, manipulation and calculation is done with Apple Macintosh computers equipped with National Instruments GPIB interfaces. Classic cubic Macs as well as modern PowerPC machines are employed. The following measurement equipment is controlled by Macs via GPIB: General purpose data acquisition units, DVMs, DSOs, precision current and voltage sources, a dynamic signal (FFT-) analyzer, lock-in amplifiers, an arbitrary signal generator, temperature controllers, and a microwave source.

Two 19″ racks typically contain about 10 instruments connected via GPIB and controlled by an Apple Macintosh computer.

The main reason for using Apple Macintosh computers was the availability of the data visualizing and analyzing program IGOR pro by WaveMetrics, which is now also available for PCs.

Some users prefer LabVIEW for their laboratory instrumentation and data acquisition. But due to its memory and processor-speed requirements, we mostly use a selfmade programming language for GPIB-programming called “IEEE”. The “IEEE” language allows the fast and easy control of the lab equipment, even with our smallest Macs in a simple PASCAL-like dialect. A typical “IEEE” program for measuring the current-voltage characteristics of an electronic device looks like this.

What is GPIB?

The General Purpose Interface Bus (GPIB) was developed in 1956 by Hewlett-Packard as the HP-IB (Hewlett-Packard Interface Bus) for interfacing laboratory equipment with computers. It is also called IEC-Bus or IEEE-Bus, because the hardware interface was documented by the IEEE commission as the IEEE 488.1 standard and is now the international standard IEC 625-1. The software protocols are described in the IEEE 488.2 standard. The GPIB is the most common interface for laboratory instrumentation.