Sample Servers

The project wizard creates sample code according the options selected.
The samples are provided in C# and Visual Basic with the Visual Studio project and are functional servers.

To debug the server the plug-in has to be compiled in 'Debug' mode. The Start Application is the generic server DANSrv.exe. The start application directory may need to changed in the project configuration because Visual Studio stores an absolute path in the project.

Application	Description
Wizard generated Code	In the new project Wizard Dialog sample code can be requested. This sample code shows how: - data is exchanged with the generic server part - items are defined - a device data buffer can be implemented with dynamic address space handling enabled - how items can be added to the servers address space with virtual address space browsing enabled - how the browse functions can be implemented
Simple	This is a simple server with a few items, statically defined within the code. A simulation thread increments the item values and updates the server cache. Write calls write the item value into the simulation buffer, forcing the incrementing to continue from the written value.
Properties	This sample works as the 'Simple' sample and additionally defines an handles custom item properties.
Dynamic	This sample is very similar to the 'Properties' sample but implements a dynamic item address space. At startup no items are defined in the generic server. All items are added dynamically when they are first accessed by a client. The browse mode is set to virtual and the client browse calls are handled in this sample. The return the items that could be added to the server cache. For the client this handling is invisible. It appears identical to the 'Properties' sample. The DANSrv Professional Edition is required because the Standard Edition does not support virtual browsing.
ConfigBuilder	This sample loads the item configuration from the file CfgSample.xml and creates the defined items at startup. The XML file can be modified with the ConfigBuilder application. The new configuration used when the server is restarted. No compilation is required. The sample does embed the XML file to show this possibility. To use the embedded file the sample has to be modified to use the LoadEmbedded() method in place of LoadFromExeDir(). The method call is in the code as comment.
20kItems	This sample defines 20000 items at startup and updates the first 1000 items every 100ms. It should give an impression of the performance and can be used as the base for a custom benchmark application. On a 2GHz Pentium the startup takes about 2 seconds and the CPU load is around 6%.
SerialDevice	This sample uses a serial COM port for device communication. A simple .Net stream class for serial IO is included. For tests a Device simulator console application is provided. Connect the COM1 ports of two computer with a null modem cable and start the DeviceSimulator on one computer and the OPC server on the other. At startup the DeviceSimulator sends a line with item names and the server creates these items in it's address space. The DeviceSimulator then periodically increments the item values and sends lines with the values of all items. The server customization reads these lines and updates the server cache. Items written by a client are sent to the DeviceSimulator, which displays them.
TCPDevice	This sample uses a TCP socket on port 6500 for device communication. For tests a Device simulator console application is provided. The IP address is initialized as localhost, allowing both applications to run on the same computer. At startup the DeviceSimulator sends a line with item names and the server creates these items in it's address space. The DeviceSimulator then periodically increments the item values and sends lines with the values of all items. The server customization reads these lines and updates the server cache. Items written by a client are sent to the DeviceSimulator, which displays them.
StockQuotes	This sample application shows how a server can be implemented to handle a huge number of items. The server uses the dynamic address space mode and creates items when they are first accessed. The current stock quotes are read from the Internet, showing a sample how an OPC server can access the Internet. The client accesses the server with a stock symbol as the item name. The server then tries to read the current quote for this symbol and if successful adds the item to it's address space. The item value is then periodically updated.

XDASrv Reference Manual
Sample Servers
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