Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
B-63
8 Troubleshooting
8.4 Error Status Check
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
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
FX
3U
-4AD/FX
3UC
-4AD (4-channel Analog Input)
8.4
Error Status Check
If an error occurs in the 4AD, the corresponding bit of BFM #29 (error status buffer memory) will turn on. To
solve the problem, refer to the troubleshooting method described below:
solve the problem, refer to the troubleshooting method described below:
1. Error detection (b0)
1) Description of error
If any bits from b2 to b4 are turned on, this bit (b0) will turn on.
2. Power supply error (b2)
1) Description of error
The 24 V power is not being supplied properly.
2) Remedy
Check the wiring condition or the supplied voltage.
3. Hardware error (b3)
1) Description of error
4AD may be defective.
2) Remedy
Please contact the nearest Mitsubishi Electric distributor office.
4. A/D conversion error (b4)
1) Description of error
The A/D conversion value is abnormal.
2) Remedy
Check the over-scale status data (BFM #28) to localize the error channel. After that, check to make sure
the input analog data is in the specified range.
the input analog data is in the specified range.
5. BFM reading/writing impossible (b6)
1) Description of error
While voltage input characteristics are being changed, this bit will turn on. If this bit (b6) is on, A/D
conversion data cannot be read out correctly or cannot be written to the BFM correctly.
conversion data cannot be read out correctly or cannot be written to the BFM correctly.
2) Remedy
Check the sequence program and confirm that the input characteristics (BFM #21 b0 to b3) are not being
written continuously.
written continuously.
6. Data setting error detection (b8)
1) Description of error
If any bits from b10 to b15 are turned on, this bit (b8) will turn on.
7. Averaging time setting error (b10)
1) Description of error
The averaging time (BFM #2 to #5) is not set correctly.
2) Remedy
Set the averaging time again in the range from 1 to 4095.
Bit No.
Items
Bit No.
Items
b0
Error detection
b8
Data setting error detection
b1
-
b9
-
b2
Power supply error
b10
Averaging time setting error
b3
Hardware error
b11
Digital filter setting error
b4
A/D conversion error
b12
Abrupt change detection value setting error
b5
-
b13
Upper/lower limit detection setting error
b6
BFM reading/writing impossible
b14
-
b7
-
b15
Addition data setting error