What Is GPIB?
General purpose interface bus (GPIB) is a standardized communication protocol for exchanging data between electronic devices. Initially developed by Hewlett-Packard (HP) in the 1960s, it was later standardized by the IEEE in 1975 as IEEE488, also known as IEEE488.2, making it an international standard for instrument control.
With its ability to connect up to 15 devices, including PCs, to a single interface despite varying communication speeds, GPIB is essential for linking measurement systems and other devices for coordinated operation. The overall communication speed is determined by the slowest device in the chain.
Usage of GPIB
GPIB is primarily used for automating and controlling measurement devices via PC, facilitating automatic testing and evaluation with high noise immunity and reliable communication. It is preferred for critical measurement applications, such as electrochemical measurements and surface treatment technologies, where precision and reliability are paramount. High-end instruments frequently utilize GPIB over RS-232C due to its superior speed and reliability.
Principle of GPIB
GPIB allows for high-speed, reliable communication between multiple devices connected in a star or daisy chain configuration without the need for separate interfaces or switching hubs, unlike RS-232C. Its unique connector integrates 16 signal lines for efficient data and command exchange. Devices on the GPIB network can serve as talkers, listeners, or both, but not simultaneously, with a PC typically acting as the controller to manage data flow and prevent collisions.
Other Information on GPIB
1. Comparison With LAN and USB
While GPIB remains a robust standard for instrument control, newer communication standards like LAN and USB are gaining traction for their ability to connect more devices and offer remote operation capabilities. LAN’s absence of GPIB’s physical limitations and USB’s user-friendly connectivity support modern measurement setups, although compatibility with older instruments may influence the choice of communication standard. Despite the higher speeds of USB2.0 and LAN, the specific needs of measurement and data processing often dictate the practical speed difference.
2. IEEE488 and IEEE488.2
IEEE488.2 builds upon the IEEE488 standard by specifying commands, data formats, and enhanced communication protocols between instruments and information devices, making it a more comprehensive standard for electronic communication.