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PV500-67 03/17
6. WIRING
Modbus RTU uses the same wiring practice and wire as BACNET MSTP.
6.1 TYPICAL WIRING DETAIL
Figure 3
Wiring of a typical Modbus RTU network with XR10CX devices
6.2 PROPER WIRING EXAMPLE
Figure 4
Correctly wired RS-485 Daisy Chain
6.3 IMPROPER WIRING EXAMPLE
Figure 5
Wiring is not correct. Not a daisy chain and the master is not at an end.
MASTER
(CLIENT)
DE
V
ICE
1
X
R10
CX
DE
V
ICE
2
X
R10
CX
DE
V
ICE
3
X
R10
CX
DE
V
ICE
4
X
R10
CX
MASTER
(CLIENT)
DE
V
ICE
1
X
R10
CX
DE
V
ICE
2
X
R10
CX
DE
V
ICE
3
X
R10
CX
DE
V
ICE
4
X
R10
CX
Master
Regis
ter
Addr
ess
(LSB
yte)
Data
(MSByte)
G
N
D
Data
(LSB
CRC
(LSByte)
C
R
T
X
TXD1 & RXD1, DATA(B)+
+
R
e
D
a
Data
(LSByt
e)
CRC
(LSByte)
2
-
W
CONNECT
GND/SHIELD AT EACH
DEVICE. NO
CONNECT AT END
XR10CX
LT
LT
C
R
C
