PXI stands for "PCI eXtensions for Instrumentation." It is a modular hardware platform used primarily for automated testing and measurement applications. PXI combines the PCI bus standard with a rugged, compact design, making it suitable for various industries, including telecommunications, aerospace, and automotive. The PXI system consists of a chassis, controller, and various interchangeable modules that can perform different functions, such as data acquisition, signal generation, and analysis. This flexibility allows engineers to customize their testing setups to meet specific requirements, improving efficiency and accuracy in their measurements.