Echelon OpenLNS Commissioning Tool - Manual (Page 44)

28 Getting Started
When designing multiple drawing files, organize the individual drawing files as subsystems within the
top-level drawing file, and limit the top-level drawing to contain only those subsystems. This
minimizes the number of drawing files that must be opened as you descend the subsystem hierarchy.
Avoid deep subsystem hierarchies with long subsystem names that results in long subsystem paths.
Subsystem paths may be stored in devices to help the network recovery process if you lose the network
database, but devices have limited memory available to store the network path. Furthermore,
visualization tools such as Wonderware’s InTouch
® have limits to item name lengths that can be
exceeded with long subsystem paths.
Network Changes
To improve network performance when making numerous network changes at one time, set OpenLNS
CT to OffNet. This will allow you to make the changes quickly, as the changes will be saved in the
OpenLNS network database instead of being sent to the physical devices. When you finish making the
changes, set OpenLNS CT to OnNet and the changes are propagated to the physical devices.
Connections
If you will be making changes to a subsystem, limit the number of connections monitored by
OpenLNS CT to less than five per subsystem. Having more than five monitored connections in a
subsystem will increase the time required to perform certain network management operations.
Alternatively, you can turn off all monitoring while making changes by right-clicking a clear space in
the subsystem page and clicking Enable Monitoring if it is currently set. You can turn monitoring on
again after making the changes.
If you are using an OpenLNS application that does not support monitor sets (groups of data points that
OpenLNS CT uses to monitor and control network variables) and you are making many bound
connections to the OpenLNS application, make the bound connections persistent. This will improve
network performance. Conversely, non-persistent bound connections, which can be created in an
OpenLNS CT network with OpenLNS applications other than OpenLNS CT, can significantly increase
the time required to open and close an OpenLNS CT drawing. OpenLNS tools that support monitor
sets, such as OpenLNS CT, enable monitoring of monitor points to be setup quickly once an OpenLNS
CT network is opened. This is because points in monitor sets are always persistent. OpenLNS CT
automatically creates monitor sets for connection monitoring when monitoring is enabled on an
OpenLNS CT network. To enable monitoring, right-click a clear space in the subsystem page and
clicking Enable Monitoring if it is not currently set. For more information on monitor sets, see the
OpenLNS Programmer’s Guide.
Sharing the OpenLNS Interface with the LNS DDE Server
If the LNS DDE Server and OpenLNS CT are running concurrently and sharing the same OpenLNS
network interface, limit the polling rate of the LNS DDE server to 10 polls per second on a
L
ON W ORKS channel. Having the LNS DDE Server polling above this rate will degrade network
performance. By default, the LNS DDE server polls active network variables every 1 second, so more
than 10 active network variables running at the default poll interval can impact network performance.
You will see similar performance degradation if you have any other OpenLNS monitoring application
sharing the OpenLNS network interface with OpenLNS CT, or if you are using connection monitoring
in OpenLNS CT.
If you will be making numerous network changes, either disable the LNS DDE Server and any other
OpenLNS monitoring applications, or reduce the polling rate to a maximum of 10 polls per second
while you are making changes.
Functional Blocks
If you have a large network with many unconnected network variables on the functional blocks, delete
the unused network variable SmartShapes. Network variable SmartShapes add performance overhead,
yet they are not required if they are not connected. You can re-add network variable SmartShapes to a