I would like to know if other process control technologies exist!

Some background understanding of OPC is required to answer your question. The OPC specifications currently only effect software to software communications. The results of this Open Process Control communication between software are lower costs and greater flexibility for customers.

• The costs are lowered due to the lower cost required for commercially developed software because more potential customers can use the product with only the one OPC interface implementation to develop.
• The flexibility is increased due to the potentially larger number of vendors to choose from for any particular application and the potential ability to use products from different vendors when this was not possible in the past.

In the past, only DDE or OLE allowed software to software communication to take place across vendors products without proprietary method being used. Microsoft is no longer supporting the advancement of DDE and COM is replacing OLE as a better and faster method for both of these older technologies. OPC is a COM based specification that has large advantages in speed and flexibility over DDE. When proprietary methods are used one vendor has to pay the other vendor to be able to use their communication method. These costs naturally get passed on to the customer in one form or the other. These methods are still limited to those software firms who own the proprietary method or a product that has purchased the use of this method.

Our TOP Server, for example, can communicate with other software using a number of different methods; OPC, DDE, AdvancedDDE, FastDDE, SuiteLink and PDB(iFix). These software communications methods should not be confused with the over 60 different drivers available in the TOP Server that provide device communications, for example; GE Ethernet and Modbus Serial.

Proprietary methods have the greatest potential for software to software communication speed and data transfer options depending on product implementation. Since communications depends both upon the server and the client, a high quality OPC Server and OPC Client may perform as well as any proprietary method. A client that implements its’ proprietary method better then its’ OPC method may get better results from its’ proprietary method. Having an OPC implementation in this case, may still allow the customer to choose to use products that better meet their needs in areas other than software product communications. In many cases, even lower quality OPC implementation will allow a product to gain the advantages of software it doesn’t have a proprietary version of to use.

In summary, there are only three basic methods of software to software communications in Process Control. DDE is the old open system method that is technologically inferior, but still available with many products. Proprietary methods are a second option, but can limit the potential options for customers currently and in the future. OPC is the open systems method that can provide the most flexibility with the potential for high speed performance. For more information see our site: https://www.softwaretoolbox.com/resources.html