Mitsubishi Electronics MELSEC-F Manuel D’Utilisation

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B-37
5 Buffer Memory (BFM)
5.4 Buffer Memory Details
A
Comm
on I
te
ms
B
FX
3U
-4AD
FX
3UC
-4
A
D
C
FX
3U
-4A
D
-A
D
P
D
FX
3G
-2A
D
-BD
E
FX
3U
-4DA
F
FX
3U
-4D
A
-AD
P
G
FX
3G
-1D
A
-BD
H
FX
3U
-3
A-
ADP
I
FX
3U
-4
A
D
-P
T
       
         
   -
A
D
P
J
FX
3U
-4A
D
-P
TW
     
        
      -
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)
5.4.12 BFM #29: Error status
Initial value: H0000
Numeric data type: Hexadecimal (H)
Error data is assigned to the bits of BFM #29.
2. Caution regarding error status
If the error cause is eliminated, the error bit will turn off.
Do not directly write "H0000" in BFM #29 using a sequence program.
3. Error status data automatic transfer function (b8 of BFM #22)
If the error status data automatic transfer-to data register is specified in BFM #129, the data in BFM #29 can
be transferred to the specified data register.
When an error is detected, data will be automatically transferred from 4AD to the PLC. For this reason, the
PLC does not need any program for reading the data, and the scan time of the PLC can be shortened.
 : Represents a numeric value.
1. BFM #29 Bit Assignment 
Bit No.
Item
Description
b0
Error detection
If any bits between b2 and b4 are turned on, b0 will turn on.
b1
-
-
b2
Power supply error
The 24 V power is not supplied properly. Check the wiring condition 
or the voltage supplied.
b3
Hardware error
FX
3U
-4AD/FX
3UC
-4AD may be defective. Please contact the nearest 
Mitsubishi Electric distributor office.
b4
A/D conversion error
The A/D conversion value is abnormal.
Check the over-scale status data (BFM #28) to localize the error 
channel.
b5
-
-
b6
BFM reading/writing 
impossible
If change in the input characteristics is started, this bit will turn on. If 
this bit (b6) is on, A/D conversion data cannot be read out correctly.
b7
-
-
b8
Data setting error detection
If any bits between b10 and b15 are turned on, b8 will turn on.
b9
-
-
b10
Averaging time setting error
The averaging time (BFM #2 to #5) is not set correctly.
Set the averaging time again in the range from 1 to 4095.
b11
Digital filter setting error
The digital filter value (BFM #6 to #9) is not set correctly.
Set the digital filter value again in the range from 0 to 1600.
b12
Abrupt change detection 
value setting error
The abrupt change detection value (BFM #91 to #94) is not set 
correctly.
Correctly set the value again.
b13
Upper/lower limit error 
detection value setting error
The lower limit error detection value (BFM #71 to #74) or the upper 
limit error detection value (BFM #81 to #84) is not set correctly.
Correctly set the value again.
b14
-
-
b15
Addition data setting error
The addition data (BFM #61 to #64) is not set correctly.
Set the addition data again in the range from -16000 to +16000.
Convenient function 
setting
Automatic data transfer function
ON = Valid
Transfer-from memory
Transfer-to data register specification 
(BFM #129: K )
BFM #22 b8:ON
BFM #29
D