Profibus is a protocol which is actually Process Field Bus, has been developed by PLC producers. It is a communication protocol that has been designed for wide manufacture and process automation. In this protocol, every bus has 32 user, the total number of user is 126. Data transmission distance is 12 km for electrical wires and 23,8 km for optical wires. Besides slaves and field components could be out and in while working.
There is 3 different communication protocols for using area. These are:
- DP,
- PA,
- FMS.
Profibus DP
Profibus DP is most used one because of its low cost. In the other hand it makes communicate fastly between automation device and non central devices. The CPU in central reads input informations from slaves, process and write them to the outputs of slaves. Most of users use this protocol for control devices like sensors, servo motors from one center in automation.
Although it is high speed because of using RS475 and fiber optical as infrasturcture.
DP works with 2 different ways:
- Mono Master (1 user)
- Multi Master (2+ users)
PA
Mostly takes a place in process automation. This protocol ensures supply the power for components via its infrastructure communication wires. In the meantime it works in the same master with Profibus DP.
FMS
Consumers use FMS is mostly for solve the complicated communicate tasks between PLC’s and DCS’s. However, with the development of TCP-IP, this protocol is not taking place as past. Like DP, FMS uses fiber optical infrastructure.