Profibus is one of the advanced communications used in the process plants usually in cement and pulp and paper plants. The Profibus cabling provides high speed communications for field devices to provide data online 24 X 7 to control systems like PLCs or DCS.
Profibus comes in two stages or basically are of two types:
1. Profibus DP (Decentralised Periphery)
2. Profibus PA (Process/Plant Automation)
The Profibus PA is the main communication protocol which communicates from the field device and instruments to the central station or cluster. The Profibus PA works on the principle of Manchester Bus Powered Philosophy. More about it can be known here. The speed of transmission in Profibus PA is 31.25 kilo bits per second.
PA can supply power over the bus (2-wire communication) for devices such as transmitters and positioners which can be extended into non-habitable environments also. All PA transmitters are connected to PA segments or clusters which then pole the data from each transmitter and send it to Profibus masters or Linking Devices.
The Profibus DP on the other hand, is high speed transmissions used in between the controllers or DCS and the clusters. These transmit data at faster speed of upto 12Mbits per second. DP is used to collect data from various PA clusters at the same time.
The Profibus DP can provide cabling redundancy by cross cabling between two profibus master cards. The Profibus DP redundancy is achieved using the Profibus connectors or terminators which loops or terminates the Profibus DP at each cluster from the Profibus master to the last cluster.
Profibus comes in two stages or basically are of two types:
1. Profibus DP (Decentralised Periphery)
2. Profibus PA (Process/Plant Automation)
The Profibus PA is the main communication protocol which communicates from the field device and instruments to the central station or cluster. The Profibus PA works on the principle of Manchester Bus Powered Philosophy. More about it can be known here. The speed of transmission in Profibus PA is 31.25 kilo bits per second.
PA can supply power over the bus (2-wire communication) for devices such as transmitters and positioners which can be extended into non-habitable environments also. All PA transmitters are connected to PA segments or clusters which then pole the data from each transmitter and send it to Profibus masters or Linking Devices.
The Profibus DP on the other hand, is high speed transmissions used in between the controllers or DCS and the clusters. These transmit data at faster speed of upto 12Mbits per second. DP is used to collect data from various PA clusters at the same time.
The Profibus DP can provide cabling redundancy by cross cabling between two profibus master cards. The Profibus DP redundancy is achieved using the Profibus connectors or terminators which loops or terminates the Profibus DP at each cluster from the Profibus master to the last cluster.
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