OPC: Easier software; IEC 61131-3 programming for unified architecture, training
Newburyport, MA and Gorinchem, The Netherlands – Translating information by using OPC automation software tools has become easier with a new Easy Connect Suite from Softing TechInfo, and PLCopen has reactivated a committee to work on application specific information models for IEC 61131-3 programming languages within OPC Unified Architecture (UA). Also, OPC Foundation is offering a Sept. 4 seminar on OPC.
Easier programming for OPC software
Softing’s OPC Easy Connect Suite will enhance OPC-based applications as the intelligent set of OPC middleware products simplifies commissioning and operation of OPC clients and servers, while improving data throughput of OPC interfaces.
Standard OPC DA (Data Access) is based on Microsoft’s DCOM technology and is restricted to the Windows operating system. DCOM communication is blocked by firewalls that prevent clients from accessing data over a wide-area network and the Worldwide Web. However, there are a growing number of applications that need to go beyond the standard OPC DA architecture. Certain applications require OPC communications between OPC Clients and/or OPC Servers. Other scenarios include OPC communications between different operating systems or through firewalls.
An example that demonstrates how to effectively complement the OPC standard with Softing’s OPC middleware products is Bixby International Corporation, a custom thermoplastic sheet extruder and laminator faced with the task to set up an OPC application consisting of a SCADA system running Windows XP SP2 and a gauging application running on Windows 2000. The seemingly easy task turned into a struggle with security settings of the underlying DCOM system.
The OPC Tunnel, part of Softing’s OPC Easy Connect Suite, is an effective solution that bypasses DCOM and enables high-performance and robust communications between OPC components on networked computers. OPC Tunnel components are installed on the OPC client computer and the OPC server computer. Communications between the client-side and server-side OPC Tunnel components is realized over a TCP/IP connection (encrypted, if desired). The data between client and server applications is thus tunneled via TCP/IP, bypassing DCOM, and eliminating DCOM set-up work.
Softing’s OPC Easy Connect Suite enhances OPC-based applications. The intelligent set of OPC middleware products simplifies commissioning and operation of OPC clients and servers, improves data throughput of OPC interfaces, and ensures reliable OPC communication links.
Technical committee for IEC 61131-3 and OPC UA
PLCopen re-activates Technical Committee TC4 Communications with a new working item IEC 61131-3 Information model in OPC UA. OPC Foundation is developing new specifications called Unified Architecture (OPC UA). Sector- or application-specific information models are part of the specifications. Such models are under development for Electronic Device Description (EDD) or Field Device Tool (FDT). It is important that the PLC, as the main component of automation systems, remains or becomes visible in the vertical information integration, which will be influenced by OPC UA. Its servers, which represent their underlying manufacturer-specific PLCs in a similar IEC 61131-3 based manner, will provide an advantage for client applications as visualizations or MES systems. PLC vendors may reduce costs for the development of OPC UA servers if an IEC 61131-3-based information model is already available in OPC UA.
The goal of TC4 is to define an IEC 61131-3-based information model as an additional part of the OPC UA specification. The necessary information model exists in the standard IEC 61131-3 (software model), but must be re-specified according to guidelines and technical requirements of OPC UA, without changing content. A co-operation with OPC Foundation will be established, resulting in a joint working group and shared documents. The first meeting is October 14 in Frankfurt, Germany, where working group objectives and plans will be decided.
Learn more about OPC at seminar
OPC Foundation is offering a Sept. 4 no-cost seminar coveringyberlogic, GE Fanuc, Iconics, Indusoft, ILS Technology, Kepware, Matrikon, Rockwell Automation, Siemens, Softing, Software Toolbox and Wonderware.