Fast DDE/DDE Suite Link

KEPServerEX makes the best use of these technologies by using only the components necessary for Wonderware users. If you are not a Wonderware user there's no need to be concerned, KEPServerEX still uses its own OPC technology to provide the best performance available for OPC client applications.

Important Note: This page will only be displayed in the server's Options menu if a Wonderware FactorySuite product is installed on your PC. Specifically, the Wonderware FS2000 Common Components or InTouch Runtime Component 8.0 or higher must be installed on your PC for proper FastDDE/SuiteLink operation.

The "Enable FastDDE/SuiteLink" option allows you to turn support of these Client/Server protocols On or Off. By default this setting will be enabled when a Wonderware product is installed on your PC. If FastDDE/SuiteLink operation is turned off, the server will not respond to any request for FastDDE or SuiteLink data. If you intend to use KEPServerEX only as an OPC server you may want to disable FastDDE/SuiteLink operation. This can increase the security of your data and improve the overall performance of the server.

The "Update active clients" option configures how often new data will be sent to attached FastDDE/SuiteLink client applications. The range is 20 to 32000 milliseconds, with a default of 100 milliseconds. The "Update active clients" timer is used to allow FastDDE/SuiteLink data to be batched up for transfer to client applications. When using a Client/Server protocol like FastDDE or SuiteLink, performance gains only come when large blocks of server data can be sent in a single response. To improve the ability of the server to gather a large block of data, the update timer can be set to allow a pool of new data to accumulate before being sent to a client application. An important thing to remember is that this update rate applies to how often data is sent to the client application not how often the data is read from your device. You can still use the tag setting "DDE scan rate" to adjust how fast or slow the server acquires data from an attached device.

Using KEPServerEX data in Wonderware
This section describes the changes that have been made to KEPServerEX to support FastDDE/SuiteLink operation and how those changes can be used to get data into your FactorySuite application. This section doesn't get into the specifics of connecting with FactorySuite. That can be found in the our connectivity guide supplied with your purchased product or available from our web site.

KEPServerEX is first and foremost an OPC server, as such common FastDDE/SuiteLink nomenclature such as DDE Service name, Topic name, and Item name are applied differently from their OPC equivalents.

Like any DDE server KEPServerEX must register itself as a DDE service provider. To do so a DDE Service name must be registered with the system. Normally this name can be anything your application may require. For proper FastDDE/SuiteLink operation this name must match the name of the KEPServerEX executable file which is "Servermain". With this in mind you must use this name when you configure an Access Name in your FactorySuite application. If you intend to use SuiteLink as your Client/Server protocol you must also configure a PC node name. This applies even if KEPServerEX and your FactorySuite application exist on the same PC.

As shown here the Access Name dialog "Node Name" must match the name of your PC if you intent to use SuiteLink. The "Application Name" must match the predefined DDE Service name of "Servermain" for both FastDDE and SuiteLink operation. The "Topic Name" is one area where KEPServerEX has been enhanced to make using the server within the FactorySuite environment easier.

Normally as an OPC server KEPServerEX provides a complex hierarchical structure to manage how individual items are referenced in the server. For an OPC client this normally doesn't present a problem due to the support of tag browsing. DDE client applications historically have relied on a much more simplified Application|Topic!Item method of referencing data within a server. If you look at a typical KEPServerEX application you may see a configuration that appears similar to the following:

If you review the section on how to use KEPServerEX data in a DDE application you would find that the tag "ToolDepth" could be access as follows: Application Name = Servermain Topic Name = _ddedata Item Name = Channel1.Device1.Machine1.Cell2.ToolDepth As shown here the actual topic name is the default topic of "_ddedata". The item name is "Channel1.Device1.Machine1.Cell2.ToolDepth" which encompasses the whole path to the item. As can easily be seen this would make using KEPServerEX data very time consuming when establishing your FactorySuite tag database. To make this easier KEPServerEX supports an Alias Map function to provide DDE topic names. The Alias Map feature has been a part of KEPServerEX since its inception, however with the addition of FastDDE/SuiteLink support the Alias Map will now automatically be generated as you create your KEPServerEX application. Using the KEPServerEX project shown above the Alias Map generated would appear as follows:

Now that the server has generated an Alias Map for the project, DDE data can be accessed using the following information:

Application Name = Servermain
Topic Name = Channel1_Device1_Machine1_Cell2
Item Name = ToolDepth
The most apparent gain here is in the Topic Name and the Item Name. Using the automatically generated Alias Map you can now define a FactorySuite Access Name that contains all of the information needed to access a data item in KEPServerEX.

As shown in the Access Name dialog above, the Alias Map generated Topic Name can now be used. When defining a new tag in your FactorySuite tag database the entry of KEPServerEX tag would appear just as it should for any FastDDE/SuiteLink driver.

Note: FastDDE, SuiteLink, FactorySuite, InTouch and Wonderware are all registered Trademarks of Wonderware Corporation.