Setting the term, -bias, and +bias switches, Setting the term, -bias, and – Rockwell Automation 22-COMM-B PowerFlex BACnet MS/TP Adapter User Manual
Page 20

2-4
Installing the Adapter
Setting the TERM, -BIAS, and +BIAS Switches
The adapter’s TERM, -BIAS, and +BIAS switches (
) are used
to turn on/off its built-in termination resistor and bias resistors.
Figure 2.2 Setting the TERM, -BIAS, and +BIAS Switches
Since nodes on a BACnet MS/TP network are typically a mix of
Allen-Bradley PowerFlex drives and other brands of building automation
products, the network node locations for the PowerFlex drives will
determine how their adapter’s TERM, -BIAS, and +BIAS switches
should be set.
104
0
0
0
1
0
1
1
116
0
0
1
0
1
1
1
105
1
0
0
1
0
1
1
117
1
0
1
0
1
1
1
106
0
1
0
1
0
1
1
118
0
1
1
0
1
1
1
107
1
1
0
1
0
1
1
119
1
1
1
0
1
1
1
108
0
0
1
1
0
1
1
120
0
0
0
1
1
1
1
109
1
0
1
1
0
1
1
121
1
0
0
1
1
1
1
110
0
1
1
1
0
1
1
122
0
1
0
1
1
1
1
111
1
1
1
1
0
1
1
123
1
1
0
1
1
1
1
112
0
0
0
0
1
1
1
124
0
0
1
1
1
1
1
113
1
0
0
0
1
1
1
125
1
0
1
1
1
1
1
114
0
1
0
0
1
1
1
126
0
1
1
1
1
1
1
115
1
1
0
0
1
1
1
127
1
1
1
1
1
1
1
Table 2.A MAC Address Switch Settings (UP = 1 = OPEN) (Continued)
MAC
Address
Switch Setting
MAC
Address
Switch Setting
SW1 SW2 SW3 SW4 SW5 SW6 SW7
SW1 SW2 SW3 SW4 SW5 SW6 SW7
Switches
Description
Default
SW1
Turns on/off the termination resistor
Up (Off)
SW2
Turns on/off the -bias resistor
Up (Off)
SW3
Turns on/off the +bias resistor
Up (Off)
SW4
Reserved (not used)
—
UP = OFF
TERM Switch (SW1)
-BIAS Switch (SW2)
+BIAS Switch (SW3)
RSRV Switch (SW4)
Reserved for future use
1
4
3
2