User's Guide _______________________________________________________________________
32 ___________________________________________________________________ M211399EN-G
Wiring HMW95
The RS-485 line of the transmitter is isolated from the power supply. A
separate ground reference terminal (GND) is provided for the RS-485
connection.
If you are using a shielded cable, you can use the Shld terminal to hold
the exposed part of the shield. Note that the Shld terminal is floating
(not electrically connected).
1209-014
Figure 23 Wiring HMW95
Connecting Several Transmitters on Same RS-485
Line (HMW95)
Set the RS-485 termination jumper to “ON” on the transmitter that is at
the end of the line. This terminates the line with a 120 Ω resistor. For
location of the jumper, see section Transmitter Parts - Inside on page 6.
Connect the cable shield to ground on the building controller side.
1209-015
Figure 24 Several Transmitters on Same RS-485 Line
D- -VsD+ +Vs
+
-
Power supply
18 ... 35 VDC
or 24 VAC ±20%
RS-485
Shld GND
Tr
ans
mit
ter
D-
-Vs
D+
+V
s
Shld
GND
Building control
ler Tran
smi
tter
Tra
nsm
itt
er
P
owe
r
s
upply
D-
D+
+Vs
-Vs
GND
SH
IELD
RS-485:
BA
Cnet or
MO
DBU
S
mas
ter
C
onnect shield
on cont
roller side
Set
RS-485
t
ermination ju
mper
D-
-Vs
D+
+Vs
Shld
GND
D-
-V
s
D+
+
Vs
Shld
GND
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