Advosol
Advosol offers the most complete .NET support for all major OPC standards:
.Net OPC Solutions
Before the first OPC specification was published each application needed a set of drivers to be able to communicate with devices from different vendors. The OPC specification simplified the situation dramatically. Server and client applications had to implement only the OPC interface and with this standardized interface the clients can access servers from different vendors.
Classic OPC defines interfaces for DA (Data Access), HDA (Historical Data) and AE (Alarms and Events) based on the Microsoft DCOM technology.
With the appearance of .NET and web services based communication the situation became more complicated. Instead of a single OPC interface there are now:
♦ .NET wrappers for classic OPC (with vendor specific application interfaces).
♦ The XML DA specification with .NET 2 based web service communication
♦ The OPC UA multi-platform specification with UA specific communication
♦ The OPC .NET (Xi) specification with WCF (Windows Communication Foundation) based communication
The vast majority of installed applications are still classic OPC DA but increasingly applications are implemented on the newer OPC specifications. Clients more and more often need to access different types of OPC servers. This can be achieved either with converter servers or multi-specification client development components.
Advosol offers multi-specification client development components and a range of converter servers.
OPC .NET Product Overview
Advosol Inc. offers the most complete .NET support with .Net Wrappers for the OPC client development, Server Toolkits with .Net customization module and OPC-XML gateways.
We have decades of experience developing and selling software components and know what it takes to for the user to achieve maximum cost savings:
♦ Robust, full featured, efficiently coded and well tested software
♦ Comprehensive documentation, guides and samples
♦ Tools for development, testing and deployment
♦ Support for the component usage and it's interaction with other components
All our products are OPC compliance tested and include tools, wizards, samples, documentation and free support.
With multiple OPC specification in use it's unavoidable that client and server happen to be implemented on different specifications and need to communicate thru a converter server.
The converter may be a separately installed server or may be built into the client application as part of an OPC interface module. Built-in converters have the advantage that there is only one type of external communication.
OPC .NET ( Xi )
OPC .NET ExpressInterface
The OPC .NET (Xi) ExpressInterface specification is designed to deliver secure and reliable real-time and historical data communication based on .NET3.5/4 WCF (Windows Communication Foundation).
Advosol offers Xi components and Xi enhancement options for The Advosol OPC server and client products.
Xi delivers fast and secure communication through firewalls and for simple implementation and use. Xi is based on MMS (Multimedia Messaging Service) and .NET3.5/4 WCF (Windows Communication Foundation).
The main design goals were:
Secure communication through firewalls and fast local communication
Reliable communication with error recovery
Simple structure to make servers and clients easy to implement
Functionality similar to OPC DA, AE and HDA combined into a single interface 
Advosol was a charter member of the Xi Specification Consortium and was actively involved in the design process and the implementation of the sample Xi server and Xi client code.
Advosol is the first vendor to offer developer components for Xi Server and client applications. We also enhanced our OPC DA .NET Client Component and OPC DA .NET Server Toolkit with Xi options that offer developers the option to gradually replace DCOM OPC applications with Xi.
OPC XML Webservices
OPC Web Services
Web Services are currently the only high-level application-to-application communication technology embraced by virtually all platform providers including Microsoft, IBM, Sun, and Linux.
XML (eXtensible Markup Language) is one of the key enabling technologies for achieving global interconnectivity and it has industry-wide support as a standardized way of handling data among systems using a variety of operating systems. On a higher layer the SOAP specification defines remote procedure call messages in a platform independent fashion, using XML. Web services such as XML DA or UA base on SOAP and are defined in WSDL documents.
OPC UA
UA Client Components:
The Advosol OPC UA client components are designed for the support of multiple OPC specifications and simple migration from DCOM based Classic OPC.
UA Server Toolkit:
The Advosol UA Server Toolkit is designed for simple migration from DCOM based Classic OPC to OPC UA.
UA Converter Servers:
High performance converter servers for access from Classic OPC clients to OPC UA servers respectively UA clients to Classic OPC servers.
Software Sources Ltd. is serving as Advosol Reseller.