4 Wiring
4.3 Grounding
31
FX
3U
-J1939 User's Manual
1
Introduc
tion
2
Specifi
cations
3
Inst
allati
on
4
Wi
rin
g
5
Al
lo
ca
tion of
Buf
fer
Memor
ies
6
J1939 C
omms
Mode
7
La
ye
r 2
C
omm
uni
cation
M
ode
8
PL
C RUN>
S
TOP
Me
ssag
es
9
Co
mmand
Interface
10
Comm
uni
cation
Setti
ngs
Proc
edure
4.2.3
Grounding of twisted pair cable
Strip a part of the coating of the shielded twisted pair cable as shown below, and ground at least 35 mm
(1.38") of the exposed shield section.
4.2.4
Termination
The J1939 network requires terminating resistors for both network ends. When FX
3U
-J1939 is the network
end, connect the included terminating resistor (120
1/2W) between pin number 2 (CAN_L) and 4 (CAN_H).
4.3
Grounding
Ground the cables as follows
• The grounding resistance should be 100
or less.
• Independent grounding should be established whenever possible.
Independent grounding should be performed for best results.
When independent grounding is not configured, perform "shared grounding" as shown in the following
figure.
For further information, refer to the respective PLC manual.
Refer to FX
3G
Hardware Edition
Refer to FX
3GC
Hardware Edition
Refer to FX
3U
Hardware Edition
Refer to FX
3UC
Hardware Edition
Refer to MELSEC iQ-F FX5U User's Manual (Hardware)
Refer to MELSEC iQ-F FX5UC User's Manual (Hardware)
• The grounding point should be close to the FX
3U
-J1939, and all grounding wires should be as short as
possible.
Shielded twisted pair cable
Shield
FX
3U
-
J1939
Other
equipment
Shared grounding
Good condition
Shared grounding
Not allowed
Independent grounding
Best condition
FX
3U
-
J1939
Other
equipment
FX
3U
-
J1939
Other
equipment
