Profibus PA, the process automation profile, has been enhanced by Profibus International as a superset of the existing DP device-orientated profile – itself aimed at data transfer between PCs/PLCs and remote I/O, switches and transducers.
According to Reinhold Achatz, R&D manager for Siemens Automation in Germany, whereas PA was formerly based on FMS, this has now been abandoned. Instead, the high speed (12Mbps) version of Profibus DP has been enhanced to provide asynchronous comms, diagnostics and alarm messaging and transmission of device status along with existing cyclic I/O data transfer.
Achatz: `It means that Profibus DP and Profibus PA are now entirely compatible. The new Profibus PA will handle modern field devices like process transmitters, drives, MMIs and positioners’.