Rockwell Automation 20-COMM-B BACnet MS/TP Adapter - Manual (Page 21)

Installing the Adapter 2-5
Network with PowerFlex Drives at Starting and/or Ending Nodes
For a network with PowerFlex drives at the starting and/or ending nodes
(
Figure 2.3 ), set their 20-COMM-B adapter’s TERM, -BIAS, and +BIAS
switches to the “Down” (On) position. All other PowerFlex drive
network nodes must have these switches set to the “Up” (Off) position.
Figure 2.3 Example Network with PowerFlex Drives at Starting and/or Ending Nodes
Network with PowerFlex Drives at Other Nodes
For a network with PowerFlex drives at other node locations — not
starting and/or ending nodes (
Figure 2.4 ), set the TERM, -BIAS, and
+BIAS switches to the “Up” (Off) position. In this network scenario,
other brands of building automation products at the starting and/or
ending nodes require appropriate termination and bias resistors. Refer to
their instruction documentation for details.
Figure 2.4 Example Network with PowerFlex Drives at Other Nodes
BACnet MS/TP Network
Node 1
(Starting Node)
Node n
(Ending Node) Node 2 Node 3 Node 4
"Down" (On) Positions "Up" (Off) Positions
20-COMM-B Adapter Settings for
TERM, -BIAS, and +BIAS Switches
"Down" (On) Positions
■ ■ ■
BACnet MS/TP Network
Node 1
(Starting Node)
PowerFlex 7-Class Drives
Other Brand
Building Automation
Product
Node n
(Ending Node)
"Up" (Off) Positions
Node 2 Node 3 Node 4
Requires
Termination and
Bias Resistors
■ ■ ■
Other Brand
Building Automation
Product
Requires
Termination and
Bias Resistors
20-COMM-B Settings
for TERM, -BIAS, and
+BIAS Switches