Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
C-14
3 Wiring
3.4 Analog Input Line
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-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.
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).
( : Channel number).
3.5
Grounding
Grounding should be performed as stated below.
• The grounding resistance should be 100
• The grounding resistance should be 100
Ω 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.
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