Access items using the DDE/SuiteLink communications protocol

For DDE/SuiteLink communications, the protocol addresses an element of data in a conversation that uses a four-part naming convention. The naming convention includes the node name, application name, topic name, and item name. The fully qualified DDE/SuiteLink naming convention includes all four parts, although the optional node-name is only required for remote access.

The following briefly describes each portion of this naming convention.

node name

Computer name or host name identifying a specific node on the network. This node name is required for remote access and is optional for local access.

application name

The name of the Windows program (this Communication Driver) that accesses the data element. For data coming from or going to the GE devices via the DDE/SuiteLink plugin of this Communication Driver, the base instance name is GESRTP, and cloned instance names are GESRTP_<cloned name>.

topic name

Meaningful names configured in the Communication Driver to identify specific devices. These names are used as the topic names in all conversations with that device.

For example, FASTPOLL.

Topic names map to a device group defined in the Communication Driver.

Note: You can define multiple device group (topic) names for the same device (PLC) to poll different points or items at different rates.

item name

A specific data element within the specified topic. For example, when using this Communication Driver, an item can be a relay, timer, counter, register, and so on, in the PLC.

For more information on item names, see Item naming.