The Vnet/IP control network protocol for process automation developed by Yokogawa Electric Corporation has been accepted by the International Electrotechnical Commission (IEC) for publication as a Publicly Available Specification (PAS).

The Vnet/IP plant control network protocol is based on 1 Gbps high-speed Ethernet and features both the openness of Ethernet and the real-time capability required in plant control. Concurrent with Yokogawa’s development of the Vnet/IP control network protocol for the flagship CENTUM CS 3000 R3 system, the company has been actively engaged from the development stage in standardization activities with a view to this receiving approval as an international standard control network.

This approval of Vnet/IP as a PAS (No. IEC/PAS 62405/Ed.1) is an important step in this direction. PAS is a mechanism for popularizing new technologies in fields where technological advances occur quite rapidly, allowing for the public disclosure of specifications before the IEC officially certifies the technologies as international standards.

Masatoshi Nakahara, General Manager of the Process Automation Product Marketing Department, says, “The fact that Vnet/IP has been accepted by the IEC for publication as a PAS means Yokogawa has gained recognition for its excellent technological capabilities and product quality. We expect that this achievement will further increase Yokogawa’s visibility and presence in the global plant control systems market. Yokogawa will continue with its standardization efforts, including the disclosure of specifications and the application of Vnet/IP in combination with products from other manufacturers, with the aim of having Vnet/IP standardized internationally in 2007* and bringing this into wider use as a standard network protocol. ”

About Vnet/IP
Vnet/IP is a core building block of Yokogawa’s VigilantPlant™ solutions that promise to bring operational excellence to visionary plants, creating an environment where plant personnel can See Clearly, Know in Advance, and Act with Agility. Using advanced Yokogawa technology, Vnet/IP achieves both TCP/IP general-purpose communications and UDP/IP-based control communications on a single network. TCP/IP is used for general-purpose communications with PCs, subsystems, and human interface stations (HISs). UDP/IP is used for control communications between HISs and field control stations. Even with large-scale plants, Vnet/IP achieves rapid response, with data update intervals of one second or less. In addition, the network can be made dual-redundant to instantly switch to another network path if a network path fails, making this a highly reliable control system. Networks can also be configured with general-purpose network equipment such as layer 2 or layer 3 switches.

*IEC activities for international standardization
Activities for the international standardization of Vnet/IP are being carried out in TC65, the IEC’s industrial process measurement and control working group. For more information,
http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=E&wwwprog=seawg.p&firstTC=65&lastTC=&Submit=Submit