Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
H-35
6 Troubleshooting
6.4 Program Check
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-3A-ADP (2-channel analog Input, 1-channel analog output)
A
Comm
on I
te
te
ms
B
FX
3U
-4AD
FX
3UC
-4
A
D
C
FX
3U
-4A
D
D
-A
D
P
D
FX
3G
-2A
D
D
-BD
E
FX
3U
-4DA
F
FX
3U
-4D
A
A
-AD
P
P
G
FX
3G
-1D
A
A
-BD
H
FX
3U
-3
A-
ADP
I
FX
3U
-4
A
D
-P
T
-
A
D
P
J
FX
3U
-4A
D
D
-P
TW
-
A
A
D
P
4. Output setting data
Check that the special device of the selected channel is correctly selected. This special device should be
selected depending on the connected position and the channel.
selected depending on the connected position and the channel.
5. Averaging time
Check that the set averaging time is within the specified range. The averaging time should be set in the range
from 1 to 4095. If the set averaging time is outside the specified range, an error occurs.
from 1 to 4095. If the set averaging time is outside the specified range, an error occurs.
6. Setting whether or not each channel is used
Check whether each channel is set correctly.
Set a channel to OFF when using it. Set a channel to ON when not using it.
Set a channel to OFF when using it. Set a channel to ON when not using it.
7. Error status
Check that no error is detected in the 3A-ADP.
If an error is detected, check the details of the error, and then check the wiring and programs.
If an error is detected, check the details of the error, and then check the wiring and programs.
→ For a detailed description of special devices, refer to Chapter 4.
6.4
Program Check
Check the following items for the program:
1. Clearing of error status at power on
When the power is turned off and then on again, the error status should be cleared (b6 and b7 should turn off)
using the program.
using the program.
2. Check of storage devices
Verify that different values are not being stored in the same device by other parts of the program.
3. Device for setting specified digital value
Check that different values are not written to this device using other programs.
6.5
Error Status Check
If an error occurs in the 3A-ADP, the corresponding bit will turn on.
*1.
3A-ADP hardware error (b6) is valid only when use of analog input is set.
Detection of power supply error is valid only when use of the analog input channel 2 is set.
Detection of power supply error is valid only when use of the analog input channel 2 is set.
*2.
3A-ADP communication data error (b7) is valid only when use of analog input is set.
To solve the problem, refer to the troubleshooting method described below:
1. Over-scale detection (b0, b1)
1) Description of error
The input analog value (voltage or current value) is outside the specified range.
The digital value is out of the range specified for the voltage input mode (0 to 4080) or outside the range
specified for the current input mode (0 to 3280).
The digital value is out of the range specified for the voltage input mode (0 to 4080) or outside the range
specified for the current input mode (0 to 3280).
2) Remedy
Check that the input analog value is within the specified range. Also check the wiring.
Bit
Description
Bit
Description
b0
Channel-1 over-scale detection
b5
Averaging time setting error
b1
Channel-2 over-scale detection
b6
3A-ADP hardware error
(Power supply error included)
(Power supply error included)
*1
b2
Output data setting error
b7
3A-ADP communication data error
*2
b3
Unused
b8 to b15 Unused
b4
EEPROM error
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