Mitsubishi MELSEC-F FX3U Series User Manual

B-58
8 Troubleshooting
8.4 Error Status Check
FX 3U /FX 3UC Series PLC User's Manual - Analog Control Edition
FX3UC-4AD (4-channel Analog Input)
8.4 Error Status Check
If an error occurs in 4AD, the corresponding bit of BFM #29 (error status buffer memory) will be turned on. To
solve the problem, refer to the troubleshooting method described below:
1. Error detection (b0)
1) Description of error
If any of b2 to b4 is turned on, this bit (b0) will be turned 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.
5. BFM reading/writing impossible (b6)
1) Description of error
When voltage input characteristics changing is in process, this bit will be turned on. If this bit (b6) is on, A/
D conversion data cannot be read out correctly or cannot be written in the BFM correctly.
2) Remedy
Check the sequence program and confirm that the input characteristics (BFM #21 b0 to b3) are not
written continuously.
6. Data setting error detection (b8)
1) Description of error
If any of b9 through b15 is turned on, this bit (b8) will be turned on.
7. Number of averaging time setting error (b10)
1) Description of error
The number of averaging time (BFM #2 to #5) is not set correctly.
2) Remedy
Set the number of 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 Number of 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

Mitsubishi MELSEC-F FX3U Series Specifications

General

Brand	Mitsubishi
Model	MELSEC-F FX3U Series
Category	Controller
Language	English