Automation, Control & Plant Intelligence - Articles, Analysis, Reviews, Interviews & Views
Asking what the business benefits of OPC are is like asking what the benefits of plug-and-play technology are to the computer industry. More choices, better access to process data, ease of plug-and-play operation, and efficient utilization of development resources are the main benefits of OPC technology.
OPC brings the value that comes with the use of standards, including reduced training costs, reduced custom development costs, and lower long-term maintenance costs. By design, OPC-compliant products work seamlessly with one another. With this plug-and-play approach, off-the-shelf components can be brought together efficiently to solve immediate requirements. In addition, long-term maintenance and upgrading can be done by removing and replacing individual components in a system without any work needed to "wire up" the new pieces.
To illustrate the savings, imagine the increase in cost if every household appliance had its own type of wall plug. Eliminating customization drastically reduces the cost of an automation system by saving money during acquisition, installation, and maintenance.
With the introduction of OPC-compliant manufacturing automation products, users are provided their due right to select and implement systems comprised of best-in-class components without the pain of custom interfaces. This user benefit is sometimes referred to as "freedom of choice." For example, both Netscape and Internet Explorer can browse the web equally well, but people use the browser they like best. As a result of this freedom of choice, vendors will need to become more competitive and offer superior products and solutions to maintain their customers.
Besides freedom of choice, the user also has vendor independence, or "freedom from a proprietary lock." If the implemented control system is comprised of modules with proprietary interfaces, any customer who desires to upgrade any component function of the integrated whole is entirely dependent on the vendor. With OPC components, only the module of interest must be upgraded and not the entire system.
The requirement to use the original vendor is eliminated. High-priced proprietary solutions (and their expensive after-sale support contracts) will yield to lower cost OPC-enabled alternatives.
Additionally, with Plug-and-Play components, other applications in addition to the original "clients" of the data servers may now request/transmit data without the need of a vendor gateway. The result is more data access to more interested clients with less complication.
Using OPC for connectivity promotes higher quality solutions. OPC interface products are built once and reused many times; hence, they undergo continuous quality control and improvement. The components must constantly prove themselves when products from many vendors interact with them. This approach contrasts the traditional "build once, use once" interfacing approach, and encourages proven, bug-free products.
OPC enables companies to build robust and durable automation solutions quickly, choosing the right components for their specific requirements. It decreases the up-front costs and reduces long-term costs of automation and control systems. The beauty of OPC is that the 'client' system-be it in the control room or an executive's office-has to understand only one interface to get data from any device. In the past, if a user wanted to get data from a vendor's proprietary control system, the user had to buy their proprietary application-programming interface. In contrast, OPC presents the data from any control system in the same way. OPC client application can be connected to any vendor's OPC server in the same way and expect the same behavior and information from the server.
Beyond technological elegance, OPC has practical "bottom-line" implications, both for users and vendors. In the past, if a user wanted to mix and match application software systems and devices from multiple vendors, he first had to find out if the software drivers for a given device or system were available. If not, he had to pursue another solution or invest the time and money necessary to develop a custom driver using that vendor's proprietary interface. OPC eliminates the compatibility problem, allowing users to select precisely the devices and systems they want and can afford for a particular application.