Technical Bulletin

BACnet MS/TP—On-Board Communication
PowerXL DG1 Series VFD MN040010EN—May 2014 www.eaton.com 73
BACnet MS/TP Parameters and Monitoring Values
BACnet MS/TP Parameters
Baud Rate
Select the communication speed for the network. The
default value is 38400 baud.
MAC Address
The parameters of every device must be set before
connecting to the bus. Especially the parameters MAC
Address and baud rate must be the same as in the master’s
configuration. The first parameter, MAC (Medium Access
Control) address, must be unique on the network to which it
is connected. The same MAC address may be used on a
device on another network within the internetwork.
Addresses 128–254 are reserved for slaves. Addresses
1–127 are valid for both masters and slaves. The portion of
the address space that is actually used for masters in a
particular installation is determined by the value of the
Max_Master property of the device object. It is
recommended that MAC address 0 be reserved for the MS/
TP router and MAC address 255 is used for broadcasts.
Instance Number
The Device Object’s Instance number must be unique across
the entire BACnet internetwork because it is used to
uniquely identify the BACnet devices. It may be used to
conveniently identify the BACnet device from other devices
during installation.
Communication Time-out
BACnet board initiates a communication error if the board is
a “sole master” in the network for a time defined with this
parameter.
Table 96. Modbus RTU/BACnet MS/TP—P20.2
Code Parameter Min. Max. Unit Default ID Note
P20.2.1 RS485 Comm Set 0 586 0 = Modbus RTU
1 = BACnet MS/TP
P20.2.11 BACnet Baud Rate 2 594 0 = 9600
1 = 19200
2 = 38400
3 = 768000
4 = 115200
P20.2.12 MAC Address 0 127 1 595
P20.2.13 Instance Number 0 4194302 0 596
P20.2.14 Comm Timeout BACnet ms 6000 598
P20.2.15 Protocol Status 0 599 0 = Stopped
1 = Operational
2 = Faulted
P20.2.16 Fault Code 0 600 0 = None
1 = Sole Master