GPIB and Ethernet: Selecting the Better Instrument Control Bus

Ethernet, with its higher bandwidth and ubiquitous usage, seems a natural alternative to the market-leading GPIB instrument control bus for automating instruments. However, it’s not always an accurate conclusion. There are many factors to consider when determining which bus provides better performance. Most important are the bus bandwidth and latency, the device-side instrument control hardware and software implementation, and the host-side software. With the recent introduction of several instruments with Ethernet and GPIB ports, National Instruments (NI) decided to compare the actual bus performance of Ethernet and GPIB in typical test use cases. The company is testing different types of instruments with multiple buses from multiple vendors. Even at this early stage, the results indicate that the optimal bus is use-casespecific because neither bus was better at all tasks.