User's Manual

13
BACnet Settings. BACnet MS-TP Settings
• BACnet Object ID. Is the current assigned BACnet ID ( Object
Identifier ). It is a unique identification number of a device on a
BACnet network. Object assigned to the VWG is always a “device”
type. Usable ID range is from 0 to 4194302. Default is value is –1,
which disables BACnet MS-TP communication.
• Network Number. Is the current assigned network number for the VWG. Usable range is from 1 to
65534 Default is value is –1 which disables BACnet IP communication.
• MS-TP Address. Is the BACnet MAC address assigned to the VWG. It is a unique identification
number of a device on a BACnet MS-TP network and needs to be unique on that RS-485 trunk.
Usable MS-TP MAC range is from 0 to 127. Default is value is –1, which disables BACnet MS-TP
communication.
• MS-TP Baud Rate . Is the assigned Baud rate of the VWG on the BACnet MS-TP networks. All node
on the trunk need to be set to the same speed for proper operation
Valid and usable ranges are:
o 9600 Kbps
o 19200 Kbps
o 38400 Kbps
o 76800 Kbps
• ADPU Segment Timeout and ADPU Timeout. These are important MS-TP settings and should be
modified only if you master and fully understand the functions these parameter hold in BACnet MS-TP
communication. These can / could be changed only if certain problematic behaviors are encountered
in MS-TP communication. For more information, please contract your Viconics representative.
o ADPU Segment Timeout default is: 2000 ms
o ADPU Timeout default is: 3000 ms.
BACnet Settings. BACnet Table
The current table view represents the actual current BACnet value inside the VWG.
Internally, the VWG uses 2 databases. There is one that is for all the thermostat objects used on the wireless
trunk portion ( from the gateway to all the thermostats ). These objects in the wireless trunk can only be seen
in “Database Tools. View Selected Thermostat” using the configuration tool.
The other database is the one used by a 3
rd
party BACnet integration system. This database by-directionally
exchanges information with the wireless object database.
Please note that the wireless object database works on a fixed COV subscription base. The BACnet and LON
database of the VWG operate on separate set of rules as defined by the Niagara AX ™ frameworks. What this
means is that there will be difference in which the local VWG BACnet objects and the wireless objects are
handled.
Back and forth from the VWG to the wireless thermostats, the COV values are fixed to:
• 2.5% for PI demand objects
• 0.5 for all temperature ( C & F ) and humidity AV objects
• On change for all MV’s & BV’s