Digging for gold

Many companies could be more profitable if they made their production more efficient. For manufacturing and processing industries today, money is tight and worldwide markets are tougher than ever, so keeping production up and running can be more important than spending cash on updating plant control and data systems, which may often be regarded as a waste of resources. Yet they may already have the data they need to make improvements, but simply don't know it is there or how to get at it.

What sense does it make if a company's share-price can be tracked by the second on the internet if the production lines themselves don't have access to the data they need? Timely and accurate data about production can bring tremendous benefits to a company, but ironically this may be where conservative attitudes dominate. As the saying goes: if it's not broken, don't fix it.

Historically there have been technical problems in accessing real-time production data due to the fact that many production systems areas are built from equipment of mixed origin, with each machine using control systems which are either proprietary or based upon products from a single automation vendor. In the past it has been risky and expensive to connect all these disparate control systems into single a coherent whole, and such production areas have remained as automation "islands", with adjacent machines hardwired by interlocking signals.

Ideally, what is needed is a seamless and readily accessible flow of data between existing plant and computer systems supporting the company's business, so real-time information can be used to track production, inform customers and influence business decisions. Some sort of non-intrusive "evolution" is needed to drag these older production environments out of the dark ages.

There are now well-proven techniques for providing a link between the open, standard, IT environments of company-wide computer networks and even the oldest proprietary control systems on the shop floor. They are successful because they use truly open architectures and provide future-proof expandability and compatibility. Based on Ethernet, they can be implemented step-by-step with minimum disruption. First it is necessary to connect existing equipment onto a standard network. Ethernet and TCP/IP are the natural choice for getting information from the production environment. Production control equipment often has existing programming ports that are unconnected most of the time, and these can be used for connection to standard Ethernet. This can often be achieved without a PLC missing a beat and with no need for any reprogramming. Using specialist industrial Ethernet device servers this can be achieved in one step, since these devices stand with one foot in the PLC world of production systems and the other in the IT world of Ethernet and TCP/IP.

Data-gathering software applications can now communicate with production devices over Ethernet and devices on the production line can be programmed or have faults located from a central control room, or from a remote location. Ethernet takes away the restrictive nature of dedicated, proprietary networks and allows virtually any device with a communications port to access external hardware platforms with standard protocols. Once PLCs, drives, instruments and other devices have been connected in this way, real-time production data is available for use by existing industrial software. The company is now in a position to turn raw data into company-wide information that can be used to gain business advantage.

Using OPC (OLE for Process Control) and Net-DDE the multitude of proprietary industrial protocols can be turned into standard formats and despatched across the company Ethernet network. There is no limit to the number of different applications that can profit from this. With specialist device servers to provide physical communications connectivity and OPC acting as software 'glue' to other applications, companies have the opportunity to integrate their existing production assets with up-to-date network technology. This approach is a realistic and cost-effective way of bringing about an information revolution in a production environment, without needing to stop or change existing production lines.

MAC Solutions
n116@industrialnetworking.co.uk