Mitsubishi Electric FX3U-232-BD - Connecting Terminal Resistors

D-33
FX Series PLC User's Manual - Data Communication Edition
Computer Link
4 Wiring
4.3 Selecting Cables and Terminal Resistors (RS-485)
A
Common Items
B
N:N Network
C
Parallel Link
D
Computer Link
E
Inverter Communication
F
Non-Protocol Communication (RS/RS2 Instruction)
G
Non-Protocol Communication (FX
2N
-232IF)
H
Programming Communication
I
Remote Maintenance
Apx.A
Discontinued models
4.3.4 Connecting terminal resistors
Make sure to provide a terminal resistor at the end of each line.
In the case of one-pair wiring, connect a terminal resistor to the RDA-RDB signal
terminal of the communication equipment.
In the case of two-pair wiring, connect a terminal resistor to the RDA-RDB signal
terminal and SDA-SDB terminal of the communication equipment.
1. Terminal resistor type
In the case of one-pair wiring, use two terminal resistors of 110 , 1/2 W.
In the case of two-pair wiring, use four terminal resistors of 330 , 1/4 W.
Among the terminal resistors supplied with the communication equipment, select
ones with the color codes shown to the right.
2. When using the FX3U-485-BD, FX3G-485-BD, FX3G-485-BD-RJ or
FX
3U-485ADP(-MB)
The FX3U-485-BD, FX3G-485-BD, FX3G-485-BD-RJ and FX3U-485ADP(-MB)
have built-in terminal resistors.
Set the terminal resistor selector switch accordingly.
•FX
3U-485-BD • FX3U-485ADP(-MB)
•FX
3G-485-BD
Remove the upper terminal block before changing over the switch in the FX
3G-485-BD.
Removal: Loosen the terminal block mounting screws, and remove the terminal block.
Installation: Attach the terminal block, and tighten the terminal block mounting screws.
Tightening torque: 0.4 to 0.5 N•m
Do not tighten terminal screws with a torque outside the above-mentioned range. Failure to do
so may cause equipment failures or malfunctions.
For installation and removal of the terminal block, use the recommended
tool shown below or a tool having straight tip (such as screwdriver) as
shown in the right figure.
<Reference>
•FX
3G-485-BD-RJ
Manufacturer Model name
Phoenix Contact Co., Ltd. SZS 0.4  2.5
1 1 1 =110 
Brown
(10
1
)
Precision
3 3 1 =330 
(10
1
)
Orange PrecisionBrown
Terminal
resistor selector
switch
330 
OPEN
110 
Terminal
resistor
selector
switch
(0.01") (0.09")
0.4mm 2.5mm
Select a
straight tip.
with a
screwdriver
Terminal block mounting screws
Terminal resistor
selector switch
Terminal resistor
selector switch