Orion System PT-Link II BACnet2 - Manual (Page 14)

PT-Link II BACnet ® Technical Guide
PT-Link II Interface 14
Troubleshooting the PT-Link Controller
Addressing WattMaster Devices in a
BACnet
®
Network.
Each PT-Link II BACnet ® generates only one BACnet ® device regard-
less of the number of WattMaster controls connected to it. This device
will have all the properties of all the WattMaster controls connected.
The instance of the device is equal to the unit address. The properties
of each control can be differentiated by an offset of 500.
Examples:
1.) Properties of the controller address as 1 will range
from 0 to 499.
2.) Properties of the controller address as 2 will range
from 500 to 999.
3.) Properties of the controller address as 3 will range
from 1000 to 1499.
To search for the instance of a specific property, follow the next
formula:
Property Instance = ((Controller Address – 1) * 500) + Instance
Number from table.
Example:
1.) The PT-Link II BACnet ® has a Node ID equal to fi ve.
2.) Two VCM controllers connected and addressed to one and
four.
3.) Searching for the Outdoor Temperature of each controller.
4.) Instance of the Outdoor Temperature in the VCM table
equal to AI: 54.
5.) Client will only see Device 5.
6.) Under Device 5 it will see AI: 54 for the Outdoor
Temperature of the unit addressed as 1 and AI: 1554 for the
Outdoor Temperature of the unit addressed as 4.
NOTE: To simplify the calculation, we recommend that the
WattMaster controllers be addressed in sequential or-
der from one to the last controller without any unused
address(es) in between.