Soft Real Time (SRT), a currently available version, has cycle times of 5 to 10 msec and meets the demands of factory automation. It is also compatible with TCP/IP Ethernet protocol. Run-time software can be downloaded from www.profibus.com.

Currently under development for motion-control applications is Isochronous Real Time (IRT). It will be able to control up to 150 axes with a cycle time of 1 msec and jitter of less than 1 msec. IRT will use next-generation switching technology and a four-port real-time ASIC switch for implementing IRT in products. An ASIC switch allows interrupt-free redundant solutions for complex applications at low cost. The objective includes porting the Profibus motion-control profile largely unchanged to Profinet as an important contribution to protecting existing Profibus investments.

The first certified Profinet products include a gateway from Hilscher and an industrial Ethernet/Profibus link and a Profinet communications processor from Siemens. Profinet Technology and Application Guides are available at www.us.profibus.com/guide, or request a hard copy from the Profibus Trade Organization.