The General-Purpose Interface Bus (GPIB), standardized as IEEE-488, is a parallel communication interface specifically designed for connecting and controlling electronic test and measurement instruments.
Originally developed by Hewlett-Packard (as HP-IB), it became a dominant standard for instrument automation. GPIB utilizes robust, shielded cables with 24-pin "stackable" (piggyback) connectors. This design allows for flexible cabling, enabling multiple instruments to be connected in linear or star configurations via a daisy chain.
Key Specifications
- System Capacity: A single controller can manage up to 14 instruments (15 devices total on one bus).
- Addressing: Each device is assigned a unique address ranging from 0 to 30.
- Data Transfer: 8-bit parallel data transmission ensures reliable communication.
Although modern interfaces like USB and Ethernet (LXI) are widely used today, GPIB remains a critical interface in many industrial and research environments. It is valued for its high noise immunity, secure mechanical connections, and extensive software compatibility (including VISA drivers) for legacy system integration.