Echelon LNS DDE Server - Manual (Page 13)

Configuration parameters are stored in files on the device, and may be accessed
using the L ON W ORKS file transfer protocol, or by direct memory read/write for
Neuron Chip hosted devices. Configuration properties may be properties of the
device, a LONMARK object, or a network variable.
The data representation and interpretation of a configuration property is defined by
its type. The type may either be a user defined configuration property type (UCPT),
or a standard configuration property type (SCPT). SCPTs are a standard in all
L ON W ORKS devices; using SCPTs is recommended whenever possible. A master list
of standard configuration property types is contained in the LNS Utilities and
LonMark Reference help file included with the LNS DDE Server.
L
ON
M
ARK
Objects
L ON M ARK objects are collections of associated network variables and configuration
properties along with definitions of their associated behavior. L
ON
M
ARK
objects
provide the basis for application layer interoperability.
The network variable and configuration property members of a LONMARK object,
along with the interpretation of each, are defined by functional profiles. The
functional profile may either be a user defined functional profile, or a standard
functional profile. Standard functional profiles are defined and maintained by the
LONMARK Interoperability Association.
Application and Foreign Frame Messages
Application and foreign frame messages are a low-level method of exchanging data
between L
ON W ORKS devices. Each L ON W ORKS message must be given a unique
message code for identification. The message code identifies the message as a
network variable, application, foreign frame, network management, or network
diagnostic message. Network variable and application messages are used for
exchanging application data. Foreign frame messages are used by gateway
applications. Network management and network diagnostic messages are used by
the LNS Server. Application and foreign frame messages are less interoperable than
network variables because all devices that need to share information must be
designed with their message codes in agreement. The message codes are part of the
application program and are not configurable.
Devices send and receive application and foreign frame messages using message tags.
A message tag is an input or output port of a device. A device can send a message
with any message code using any of its message tags. Similarly, a message with any
code might arrive at any of the device's message tags. Establishing connections
between device message tags is another task done by an LNS network tool during
network installation.
The Role of the LNS DDE Server
The LNS DDE Server exchanges network variable, configuration property, and
application and foreign frame message data between L
ON
W
ORKS
devices and
Windows applications. With the LNS DDE Server, any Windows application that
can act as a DDE Client can monitor and control one or more L
ON W ORKS networks.
LNS DDE Server User's Guide 1-5