Echelon LNS - Manual (Page 128)

LNS Programmer's Guide 114
physical or logical segment of your network, and each Subsystem has its own
AppDevices and Routers collections. These collections contain the application devices
and routers installed on that Subsystem. You can select a subsystem that already exists
using the Item property of your Subsystems collection, or you can create a new
subsystem with the Add() method.
Set MySubsystems = MySystem.Subsystems
Set MySubsystem = MySubsystems.Item("FireSubsystem")
OR:
Set MySubsystems = MySystem.Subsystems
Set MySubsystem = MySubsystems.Add("FireSubsystem")
NOTE: You cannot explicitly add items to AppDevices collections that are contained in
the ALL or Discovered subsystems, as these read-only collections are maintained by
LNS.
2. Fetch the AppDevices collection from the selected Subsystem:
Set MyAppDevices = MySubsystem.AppDevices
3. Use the Add() method to add a new AppDevice to the AppDevices collection acquired
in step 2.
Set NewAppDevice = MyAppDevices.Add("SmokeDetector", _
MyDeviceTemplate, MyChannel, MySubnet)
The Add() method takes four parameters: the device name, a DeviceTemplate
object, a Channel object, and a Subnet object. The device name is required, and the
Channel and DeviceTemplate objects should be specified whenever possible. You
must specify a DeviceTemplate to create planned network variable connections for
the device in the engineered installation scenario.
If you do not specify the device template and channel, the device template will be
assigned (and recovered from the device if necessary) when the device is
commissioned. In this case, the device’s interface will be unavailable until the device
has been commissioned. Echelon recommends that you specify the template and
channel during device creation whenever possible.
If you do not specify the device template, any dynamic network variables on the
device’s main interface will be uploaded into the LNS database when the device is
commissioned, which may not be desirable. However, you can use the
MoveToInterface() method to move these dynamic network variables to a custom
interface, and then delete them, if desired. For more information on the
MoveToInterface() method, see Using Dynamic Device Interfaces on page 179.
For more information on device templates, see the Device Interfaces section earlier in
this chapter. For more information on channel and subnet allocation, see Managing
Networks with Multiple Channels on page 169.
Echelon recommends that you do not assign a subnet when creating AppDevice
objects, as LNS will automatically assign the best subnet to the new device, based on
the network topology and resource requirements.