Echelon IzoT BACnet Developes - Manual (Page 18)

Complex Mapping
If a Network Variable has multiple fields, each field needs to be mapped to a separate
BACnet Object. mapAnaToSNVT_hvac_overid__percent ( ) provides a mapping of
SNVT_hvac_overid.percent
to a BACnet Analog Output or Input.
It is possible for a BACnet Client to both read from and write to an Output (e.g. Analog
Output), subject to the rules of BACnet Objects, such as “Out-Of-Service” and “Priority
Arrays”
Mapping UNVTs
UNVTs are mapped in a similar fashion to SNVTs, but the mapping macro must be
defined by the OEM developer. Refer to the BAClon\mapping.h file, and use one of the
pre-defined mappings to generate an appropriate mapping for the new UNVT, and then
this new mapping can be applied to the UNVTS in BAClon\mapping.nc file.
Device Object Instance and Name
As mentioned before, a BACnet Device’s Device Object Instance and Device Object Name
must be unique across the whole BACnet Internetwork. The Toolkit automatically
generates a unique instance and name based on the IP address it has been allocated by
the DHCP server on the IzoT Router. This can be changed by the user using a suitable
BACnet Client, and once changed, will remain set in persistent storage.
BACnet Test Tools
1. BACnet Browser for IzoT –
This is a standard BACnet Client. All discovered BACnet
devices appear in the tree view in the left pane. Right clicking on a contained BACnet
Object of the appropriate type allows the Present Value and a few of its other
properties to be monitored in the right pane. This utility can be downloaded from the
following link.
http://www.connect-ex.com/demos_and_downloads/bacnet-browser-for-echelons-izot
18 Using BACnet