Echelon LNS DDE Server - Manual (Page 66)

Custom Topic Format
The custom topic format specifies a custom topic name and a topic type.
Use this format with custom topics that you define. To use a custom topic
format, specify a topic with the following two components:
Topic_name.Topic_type
Each component is separated from the other by a single period (.).
Following is a description of the two components (both components must be
specified):
Topic_name
The custom topic name that you have defined. When you
create a custom topic name, you will specify the network
name and subsystem path that the server is to use for the
custom topic. The custom topic name must not contain any
periods (.), and is not case sensitive.
Topic_type Specifies the type of information required. The topic type
must be one of the following: Netvar, NV, DevNV, LMNV,
LMCP, NVCP, DevCP, DevNVCP, LMNVCP, LM, MsgTag (MT),
Dev, or System. These types are described later in this
chapter under Topic types. The Topic_type is not case
sensitive.
To create a custom topic, see Creating Custom Topics in Chapter 3.
Examples
Below are a few examples of correctly formatted topic names:
TheTopic.Netvar
AnotherTopic.MsgTag
BldgA54_LvlB_SecK.LMNVCP
Topic Types
There are many types of information in a L ON W ORKS network. When you
are addressing a DDE message, you need to specify both the type and the
name of the item that you are accessing. The topic type tells the LNS DDE
Server where to look for the item in the LNS Server.
The topic types are grouped into the following six categories: Network
Variables, Configuration Properties, LONMARK Objects, Devices,
Application and Foreign Frame Messages, and System. In addition to this,
Network Variables and Configuration Properties are further subdivided
into several different types depending on the context. The following table
describes the topic types.
4-4 Topics and Items