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Chapter 8
Servers
©
National Instruments Corporation
8-9
How Do You Use DDE Servers with BridgeVIEW?
BridgeVIEW can communicate with any server using Microsoft Dynamic
Data Exchange (DDE) as its interface. A DDE Server is treated as a simple
server in which you type in a device and item string to select a specific
point. For DDE Servers, you select DDE Server from the Server List in
the Tag Configuration Editor, and type in
APPLICATION|TOPIC
for
device in the I/O Group Configuration Dialog Box, and
ITEM
for item. See
How Do You Connect a Tag to a DDE Server?
for more complete information on how to do this. If you are
using Network DDE to use a DDE Server running on another machine, use
the Network DDE name for the
APPLICATION
part of the name. Refer to
your DDE Server documentation for the correct name for
APPLICATION
,
the list of available
TOPICS
and
ITEMS
for each topic.
Note
Unlike the servers written to the BridgeVIEW IA Device Server specification,
off-the-shelf DDE Servers do not register themselves with BridgeVIEW.
Therefore, BridgeVIEW cannot launch the DDE Server automatically when it
runs your HMI application. To use a DDE Server, launch or run the DDE Server
before you run your BridgeVIEW application. BridgeVIEW will post system error
messages if it cannot connect to the DDE Server when it launches the
BridgeVIEW Engine. Thereafter, it attempts to reconnect to the DDE Server
periodically.
How Do You View BridgeVIEW Server Configuration?
The Tag Configuration Editor shows the list of available servers, and any
registered devices and items for the server in the various Edit Tag screens.
You also can use the Server Browser to view information about the device
servers registered with BridgeVIEW as well as the OPC Servers present in
your system and on the network. Launch the Server Browser by selecting
Projects»Server Tools»Server Browser… or by pressing the Server
Browser… button on the Engine Manager display. Use this utility to view
the properties of the devices and items registered by each server. For
VI-based IA Device Servers, you can use this utility to display the server
front panel while your application is running if you launch it from the
Engine Manager. Typically, servers run with their front panel hidden. You
can use the Server Browser to launch the server-specific configuration
utility from within BridgeVIEW, if one is available.
The Server Browser utility shows the server information stored in the active
Common Configuration Database (
.ccdb
) file. You can control which
CCDB is active from the Server Explorer utility.