Basics of Profibus-DP

Profibus DP is one of the most commonly used network in industrial automation . Profibus stands for process field bus and DP stands for decentralized peripherals. If we have a bunch of sensors and actuators in the field area that we want connect to the PLC’s I/O modules which are located 1500 feet away from in the control room.To do this we need to connect each one of these sensors to PLC with separate wire. Huge number of parallel wires are required for this. It will increase the cost of the system installation. we can avoid this by utilizing Profibus DP network. We need to install a Profibus DP IO module on PLC. In the field side we need to install remote I/O . Sensors and actuators need to be connected to this remote I/O.This remote I/O can be connected to PLC through Profibus DP.

Previously the PLC’s I/O modules were arranged centrally but by introducing a network bus between the main controller and its I/O modules we decentralized the I/O moving them to this enclosure in the field area. Thats why this type of profibus has the added suffix of DP or Decentralized Peripherals.We usually call these Decentralized peripherals "Remote I/O.So using Profibus-DP instead of wiring each individual sensor actuator or other facility to the PLC individually we can install a set of “remote I/Os” next to these facilities in the field are and then transfer the data to the control area using a single RS-485 cable.This can decrease the cost of wiring dramatically and on the to of that .Since the data transmission method here is “digital” industrial environment noise has less of an impact on data,so data communication between the control and field area will be more robust.

Disadvantages of Profibus DP Since the data transferred with a single cable if it malfunctions in any way we will lose all the data from field facilities.

Advantages of Profibus DP Profibus DP is an industrial network which decrease the amount of wiring required by decentralizing


Thanks for this very important summary