Echelon LNS DDE Server - Manual (Page 59)

Bound Update Persistent
Once the DDE Server shuts down, all temporary network variables and connections
created when using bound updates are removed automatically when the point is
deleted. To keep the temporary network variables and connections active, select this
setting. Selecting this setting improves shut-down and start-up performance if you
are using temporary network variables. The default setting is Off. See Use Bound
Updates, earlier in this chapter, for more information.
Message Options—Application Messages
Service
The setting selects the default messaging service to be used when sending
application messages from the LNS DDE Server to a device. The available settings
are Acknowledged, Repeated, Unacknowledged, or Request. The default setting is
Unacknowledged.
You can override the default messaging service with the -s switch.
Authenticate Messages
When enabled, this setting specifies that the LNS DDE Server will use authenticated
transactions for outgoing application messages that use the Acknowledged service.
The default setting is Off.
You can override the authenticated option for an individual application message with
the -a switch.
Include Sequence Number
This setting specifies the default for whether the client will receive application
message items from the LNS DDE Server even if the data has not changed from the
last time this message was received from the network. If it is False, data is reported
to the client only if it has changed. If it is True, a byte containing an incrementing
counter will be appended to each incoming message. When the counter is turned on,
the data received by the client contains the additional byte. The default setting is
False. It may be overridden with the –n switch when the DDE transaction is started
for the item.
Creating Custom Topics
As described in the next chapter, the LNS DDE Server has a number of predefined
topics that you use to identify the type of data that you are reading or writing. In
addition to these predefined topics, you may create your own custom topics to
simplify access to frequently used data. Custom topics are not required; however,
they do provide a shorthand notation for the predefined topics.
LNS DDE Server User's Guide 3-27