IS200STAIH2A
IS200STAIH2A
IS200STAIH2A
power supply, but also to meet the essential safety and explosion-proof requirements.
Due to the advantages of fieldbus, many influential fieldbuses have appeared in the past decade, such as Foundation fieldbus FF, Profibus, CAN, LONworks, HART and so on, and have been widely used. Only the first two fieldbuses are briefly described below.
3 Introduction to main fieldbuses
3.1 Foundation Fieldbus FF
Foundation Fieldbus is a kind of fieldbus formed by several fieldbuses in the world after fierce competition and launched by Fieldbus Foundation. Unlike the private network bus protocol, the FF bus is not affiliated to any one enterprise or country. Its bus architecture is a communication model established by referring to the physical layer, data link layer and application layer in the OSI model of ISO, and adding
the user layer. FF has the support of almost all the famous instrument manufacturers in the world, and complies with the IEC protocol plan, the basic principles of the IEC Fieldbus international standard and draft, together with its technical advantages, so it is very promising to become a major international standard in the future.
The FF bus provides two physical layer standards, Hl and H2. Hl is a low-speed bus for process control, with a transmission rate of 31.25Kbps and a transmission distance of 200m,
