The IEEE488 standard, also known as GPIB, is a bus interface that connects instruments with a computer to form an ATE system. GPIB was initially developed by Hewlett Packard and was recognized as an IEEE standard in 1978. The IEEE488.1-1978 standard defines the convention for electrical and mechanical bus characteristics, as well as the state diagram for each bus function. In 1987, another standard derived from IEEE488.1-1978, known as IEEE488.2-1987, was introduced to define data formats, common commands, and control protocols for instruments. In general, IEEE488.1 defines the hardware specification, and IEEE488.2 defines the software specification. The IEEE488 standard has been widely accepted by instrument vendors for decades. Today, GPIB is the most popular interface between computer and instruments.