Using Modular Instruments with VISA I/O Programming Library Software and a Translation DLL
By Andy Purcell, Agilent Technologies, Inc.
Many test systems use modular instruments, which offer numerous advantages, among which we can highlight their ability to shorten test time and minimize test system dimensions. This can be seen especially in the latest modular instruments that use PCI-Express (PCIe) cabling. These instruments are known as PXIe and AXIe instruments. PXIe [1] is the extended PCIe standard for instruments. AXIe[2] is a standard based on AdvancedTCA with extensions for instruments. Latency times for registration operations on PXIe and AXIe devices can be as low as 1,5 microseconds. With a 4-way (x4) connection between the PC and a PXIe chassis, transfer speeds can reach 2 GBytes/s. Thus, both in terms of latency and throughput, wired PCIe outperforms LAN, USB, and all other buses used in the test and measurement industry today.
