Using CitectSCADA > Exchanging Data with Other Applications > Network DDE

Network DDE

Network DDE is a version of the DDE protocol for use across a network. For information about DDE, see Using DDE (Dynamic Data Exchange). For details about setting up CitectSCADA to use DDE, see Exchanging CitectSCADA data via DDE.

Just like the establishment of a DDE conversation between applications running on the same computer, a network DDE conversation uses the same DDE protocol to share data between applications running on separate computers connected to a common network.

Network DDE is a Windows Service used to initiate and maintain the network connections, security, and shared file space needed for using DDE over a network, and needs to be running on both computers at the same time. For startup details, see Starting network DDE services.

A network DDE trusted share needs to be manually created for the Network DDE server application on the Network DDE server application machine. This instructs the Network DDE Service (on the DDE server application machine), as to which application and topic to connect with. It is this share name which the Network DDE Client application can subsequently communicate with. For details, see Setting up network DDE shares.

The Network DDE Client starts the Network DDE conversation by connecting to the Network DDE Share on the Network DDE server computer. For details, see Using network DDE.