DDE Client

Licensing starts at $485.00
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Product Overview

The DDE Client driver works in conjunction with KEPServerEX to provide data exchange between OPC clients and legacy DDE server applications. If you have an OPC client application that needs to access an existing DDE server, this driver is the solution. Data integrity is ensured with our extensive error handling.



  • The DDE Client driver is capable of communicating with any server that supports the standard CF TEXT DDE data format.
  • Clients may reside on remote machines and communicate with this driver via OPC or NetDDE. However, the current version of this driver cannot access data from DDE servers running on remote machines.
  • The driver will automatically reconnect when DDE servers are brought back on-line.
  • A ReinitializeDDE tag is provided to aid in the resolution of DDE communication failures.
  • This driver uses "hot links", where a DDE server passes data to the driver only when the data value has changed. This provides a significant performance advantage over the alternative request/response loop approach since each DDE transaction is relatively time consuming.
  • Addressing uses familiar Application Name Topic Name, and ItemName method for DDE server data.
  • All major data types are supported.


  • Dynamic Data Exchange (DDE)

Supported Devices

  • Any DDE server that supports standard Microsoft DDE

Available Languages

  • English

Application Support

  • DDE Format CF_Text and AdvancedDDE
  • NIO Interface for iFIX
  • OPC .NET Service (OPC .NET) Version 1.00
  • OPC Alarms and Events (OPC AE) Version 1.10
  • OPC Data Access (OPC DA) Versions 1.0a, 2.0, 2.05a, and 3.0
  • OPC Unified Architecture (OPC UA) Clients
  • SuiteLink and FastDDE for Wonderware

Release Notes



  • Added string array support to the server interface for the XLTable format type.



  • Fixed an issue that could cause handle leaks to occur while writing.
  • Enhanced the write error return message to include a more specific reason for the error.

Featured Suites

What Is a Driver?

KEPServerEX is more than an OPC server—it's a connectivity platform for industrial automation and IoT. Simply download KEPServerEX, and then select from Kepware's library of more than 150 device drivers, client drivers, and advanced plug-ins to fit the communication requirements unique to your industrial control system.

A driver is a software component that enables KEPServerEX to meet the connectivity requirements of a specific device, system, or other data source. The driver handles all proprietary communications to the data source for KEPServerEX; the client interfaces handle all supported OPC, proprietary, and open standards connectivity to applications that monitor or control the devices.

Drivers may be licensed individually or in suites. Additional drivers can be licensed on demand as connectivity needs evolve.