Machine builders have achieved new levels of design flexibility through the use of standard Ethernet network platform to easily connect devices across the enterprise and an entire machine, which include variable servo drives and frequency drives for integrated motion control.
The need for different networks to connect devices across an enterprise or set of machines has been long gone as several manufacturers have expanded the use of Ethernet to include most of the applications handled typically by traditional fieldbuses. These changes, which have started with information systems, found a way into I/O control and safety and now have extended to incorporate integrated motion control.
To particularly address the motion control needs, ODVA has added CIP Sync and CIP Motion technologies to the CIP network specification.
CIP Sync is a time synchronization extension to CIP, which is fully compliant with and based on the IEEE-1588 Standard for Precision Clock Synchronization Protocol for Networked Measurement and Control Systems. CIP Sync offers the improved control coordination needed for distributed motion control, demanding events sequencing and other extremely distributed applications where absolute time-synchronization of machines is very important. With the use of this technology, synchronization can be lowered to 100 nanoseconds using unmodified Ethernet hardware.
CIP Motion provides real-time, closed-loop, deterministic motion control over unmodified, standard EtherNet/IP or Ethernet. By adding CIP Sync, multiple axes can now be coordinated for precise and coordinated motion control applications. The use of time-stamped data in CIP Motion, along with its simple timing model, removes the need for any hard synchronization constraints between the controller and the drive.
Based on ODVA’s motion control advancements, new servo drive and VFD solutions can be utilized on machines with single network architecture. For instance, the enhanced Allen-Bradley PowerFlex 755 AC drive and the Allen-Bradley Kinetix 6500 servo drive from Rockwell Automation (www.rockwellautomation.com) provide integrated motion capabilities on EtherNet/IP. These products deliver high-performance, open- and closed-loop drive control that use standard IP and Ethernet technology, allowing manufacturers to unite the two drive technologies on a standard and unmodified network.