The modern plant has a TCP network as its data communications backbone. Each level of communications should be on its own segregated VLAN (virtual local area network) for both security and traffic management. Typically the network is segregated as follows:
There are a number of ways that communications data can travel:
A fibre network is now an essential backbone for the information data highway. It is not subject to RF noise and can travel great distances at high speed without interference. By installing a fibre ring main together with routable fibre network switches it is possible to create an extremely reliable high speed network with failover functionality.
For short runs copper networks still provide the best cost effective solution. It is proven and reliable and would only be replaced with fibre if running through high interference areas.
As network radios are becoming more reliable and cost effective we are seeing them increasingly used for medium to long network hops, up to 20km, with network speeds of up to 20Mbps.
With the maturing of the tablet, both iPad and Android, our clients are choosing to maximise their efficiency by installing WIFI access points allowing their operators and commissioning engineers to log onto a terminal server from anywhere within the plant and operate the HMI pages directly.