Profibus DP and Profibus PA are both industrial automation communication protocols.
Profibus DP (Decentralised Peripherals) is a fieldbus protocol used to communicate between PLCs (Programmable Logic Controllers) and field devices such as sensors, actuators, and other peripherals. It is intended for deterministic, high-speed communication across a serial bus network. Profibus DP supports data speeds of up to 12 Mbps and is ideal for applications requiring quick and accurate data interchange, such as process control and factory automation.
Profibus PA (Process Automation) is a Profibus variant specifically suited for process automation applications. It is used in industries such as oil and gas, chemical, and pharmaceutical to communicate with field devices. Profibus PA has lower data rates than Profibus DP, often up to 31.25 kbps. This decreased data rate is required in hazardous areas to maintain adherence with intrinsic safety requirements.
The power supply is one significant distinction between Profibus DP and Profibus PA. Profibus DP requires field devices to have their own power source, but Profibus PA allows power and communication to be transferred over the same two-wire bus, simplifying installation and lowering costs.
Profibus DP and Profibus PA both use a master-slave communication model in which a master device (such as a PLC) controls and coordinates communication with several slave devices (field devices). These protocols specify the data format, communication protocol, and electrical properties required for the reliable flow of data between devices in an industrial automation system.
What is difference between PROFIBUS DP and PA?
The primary distinction between Profibus DP (Decentralised Peripherals) and Profibus PA (Process Automation) is found in the applications they are meant for and the particular needs they satisfy.
Focus on Application
PROFIBUS DP is for industrial automation and discrete manufacturing applications that demand high-speed, deterministic communication. In these situations, it is often used to connect PLCs (Programmable Logic Controllers) with sensors, actuators, and other peripherals.
PROFIBUS PA is designed specifically for the process automation industries of oil and gas, chemical, and pharmaceutical. It is specifically intended to suit the needs of hazardous areas and inherently safe environments that may contain explosive atmospheres.
Data Transfer Rate
PROFIBUS DP allows for high-speed communication at up to 12 Mbps. This enables rapid data sharing, making it suited for applications requiring quick response times and high-performance control.
PROFIBUS PA protocol operates at lower data speeds, typically up to 31.25 kbps. In hazardous areas, the lowered data rate ensures compliance with intrinsic safety requirements. Process automation systems often prioritize slow and consistent control above high-speed communication.
PROFIBUS DP - Each field device connected to the network requires its own power supply. Power and communication are delivered via distinct channels.
PROFIBUS DP - Enables power and communication to be sent over the same two-wire bus, simplifying installation and lowering cabling costs. It makes use of a power delivery method known as “power over the bus.”
Types of Devices
PROFIBUS DP protocol is primarily used to communicate between PLCs and decentralized peripherals such as sensors, actuators, and motor drives.
PROFIBUS PA is designed for connecting field devices found in process industries such as transmitters, analyzers, control valves, and other process control devices.