C-14
3 Wiring
3.4 Analog Input Line
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX3U-4AD-ADP (4-channel analog Input)
3.4 Analog Input Line
For analog input, "voltage input" or "current input" can be selected for each channel.
*1. Use the 2-core shielded twisted pair cable for the analog input lines, and separate the analog input
lines from other power lines or inductive lines.
*2. If "current input" is selected, be sure to short the line between the V+ terminal and the I+ terminal.
(: Channel number).
3.5 Grounding
Grounding should be performed as stated below.
• The grounding resistance should be 100Ω or less.
• Independent grounding should be performed for best results.
When independent grounding is not performed, perform "shared grounding" as shown in the following
figure.
→ For details, refer to the User’s Manual - Hardware Edition of the PLC Series.
• The grounding wire size should be AWG22 to 20 (0.3 to 0.5 mm
2
).
• The grounding point should be close to the PLC, and all grounding wires should be as short as possible.
250
Ω
147k
Ω
ch
47k
Ω
4AD-ADP
V
+, I
+, ch
:
represents the channel number.
Terminal
block
I
+
COM
V
+
*1
I
+
COM
V
+
250
Ω
147k
Ω
ch
47k
Ω
Class-D
grounding
24+
24-
24V DC
+15V
*1
If current input is selected:
If voltage input is selected:
*2
Connection of external
power supply line
PLC
Other
equipment
PLC
Other
equipment
PLC
Other
equipment
Shared grounding
Good condition
Common grounding
Not allowed
Independent grounding
Best condition
