The worldwide exhaustion of traditional IPv4 addresses has led to the rapid development and enhancement of Internet technology and network-ready appliances. In particular, IP version 6 (IPv6) has been developed by the Internet Engineering Task Force (IETF) as the next generation Internet protocol to replace IPv4 and provide additional IP addresses for the increasing number of mobile devices and network-ready appliances. With a large number of appliances already functionally IPv6 network-ready, the transition to IPv6 is inevitable with foreseen implications for industrial control and automation arena in the near future as new industry developments and technology are introduced. As more and more network-enabled field instruments and control devices are required for various mission-critical applications, IPv6 compliance has become a critical issue.
IEEE 1588 PTP Enables Time Synchronization
For some industrial applications—such as motion control, remote monitoring and alarms, testing and measurement, and transportation management and control—synchronizing distributed network devices to a master clock is important. Using the IEEE 1588 protocol makes it possible to synchronize—to less than a microsecond—local clocks in sensors and other terminal devices using the same Ethernet network.
For example, electric power providers must synchronize network switches across large-scale distributed power grids to provide smooth power transmission and maintain power supply integrity across various systems exposed to harsh conditions such as extreme temperatures, dust, and high humidity. Reliability, durability, and longevity are particularly important for power management, and timing accuracy is critical to the operation and maintenance of power grids.
IEEE 1588 can only be implemented in software so if timestamping is executed in the application layer, interruptions and other unpredictable software processes can result in latency which may impede synchronization. To address this problem, semiconductor vendors have implemented the hardware timestamp function on integrated communications processors for customers to improve accuracy and reduce costs.
Trend at a Glance
IEEE 1588 PTP
No IPv4 addresses available in the future
Better support for security,
quality of service and mobility
Synchronization of clocks with different precision, resolution, and stability
Backbone of the future information society
Industrial network switches that synchronize sensors and actuators over a single wired distributed control network for automated assembly process control
Testing and measurement devices that must maintain accurate time synchronization with the device being tested in many different operating environments