What's Profibus (part 2)
In the previous article:What's Profibus (part 1), Profibus DP (Decentralized Peripherals) is introduced. In this part, we introduce Profibus PA (Process Automation).
Profibus PA (Process Automation) is used to monitor measuring equipment via a process control system in process automation applications.
Profibus PA (Process Automation) is designed for use in explosion/hazardous areas (Ex-zone 0 and 1). The Physical Layer (i.e. the cable) conforms to IEC 61158-2, which allows power to be delivered over the bus to field instruments, while limiting current flows so that explosive conditions are not created, even if a malfunction occurs. The number of devices attached to a PA (Process Automation) segment is limited by this feature. PA (Process Automation) has a data transmission rate of 31.25 kbit/s. But PA (Process Automation) uses the same protocol as DP (Decentralized Peripherals), and can be linked to a DP (Decentralized Peripherals) network using a coupler device. The much faster DP (Decentralized Peripherals) acts as a backbone network for transmitting process signals to the controller.
This means that DP(Decentralized Peripherals) and PA (Process Automation) can work tightly together, especially in hybrid applications where process and factory automation networks operate side by side.
By the end of 2009, 30 million Profibus nodes were installed. 5 million of these are in the process industries.
