This video, published by the PROFIBUS Group, explains a dramatic evolution in industrial automation: the transition from 4-20 mA to digital fieldbuses. It compares the two and highlights key benefits and new business models arising from the implementation of fieldbuses
The 4–20 mA convention was born in the 1950s as electronics became cheaper, and reliability began to meet the automation industry’s requirements. 4-20 mA provided a low-cost, easy to use solution and was not subject to major signal line losses. In the 1980s and 1990s, several organisations and device manufacturers started engineering the first fieldbuses such as PROFIBUS. Fieldbuses enable 2-way digital communication.