How are IEEE-488 (GPIB) systems used in automated test equipment?

GPIB connects test instruments in automated systems. Each device has 5-bit address (up to 30 devices). Controller manages communication via eight data lines, five control lines (ATN, IFC, REN, SRQ, EOI). Commands include: talk, listen, serial/parallel poll, clear, trigger. Modern implementations use USB/LAN-GPIB adapters. Programming through SCPI commands (Standard Commands for Programmable Instruments) enables instrument interchangeability. Timing considerations: handshaking limits speed to ~1 MB/s. Being replaced by LXI (LAN eXtensions for Instrumentation) for new systems but GPIB remains in legacy equipment.