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FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
38 Error Check Method and Error Code List
38.4 Error Code List and Action
Operation error [M8067(D8067)]
6748
Continues
operation
PID output upper limit set value < PID output lower limit
set value.
<Transpose of output upper limit value and output lower
limit value. → PID operation is continued.>
Verify that the target setting contents are correct.
6749
Abnormal PID input variation alarm set value or output
variation alarm set value (Set value < 0)
<Alarm output is not given. → PID operation is
continued.>
Verify that the target setting contents are correct.
6750
<Step response method>
Improper auto tuning result
<Auto tuning is finished. → PID operation is started.>
• The deviation at start of auto tuning is 150 or less.
• The deviation at end of auto tuning is 1/3 or more of
the deviation at start of auto tuning.
Check the measured value and target value, and then
execute auto tuning again.
6751
<Step response method>
Auto tuning operation direction mismatch
<Auto tuning is forcibly finished. → PID operation is not
started.>
The operation direction estimated from the measured
value at the start of auto tuning was different from the
actual operation direction of the output during auto
tuning.
Correct the relationship among the target value, output
value for auto tuning, and the measured value, and then
execute auto tuning again.
6752
<Step response method>
Improper auto tuning operation
<Auto tuning is finished. → PID operation is not started.>
Because the set value was fluctuated during auto tuning,
auto tuning was not executed correctly.
Set the sampling time to a value larger than the output
change cycle, or set a larger value for the input filter
constant.
After changing the setting, execute auto tuning again.
6753
<Limit cycle method>
Abnormal output set value for auto tuning
[ULV (upper limit) ≤ LLV (lower limit)]
<Auto tuning is forcibly finished. → PID operation is not
started.>
Verify that the target setting contents are correct.
6754
<Limit cycle method>
Abnormal PV threshold (hysteresis) set value for auto
tuning (SHPV < 0)
6755
<Limit cycle method>
Abnormal auto tuning transfer status
(Data of device controlling transfer status is abnormally
overwritten.)
<Auto tuning is forcibly finished. → PID operation is not
started.>
Ensure that devices occupied by PID instruction are not
overwritten in the program.
6756
<Limit cycle method>
Abnormal result due to excessive auto tuning
measurement time (τon > τ, τon < 0, τ < 0)
<Auto tuning is forcibly finished. → PID operation is not
started.>
The auto tuning time is longer than necessary.
Increase the difference (ULV - LLV) between the upper
limit and lower limit of the output value for auto tuning, set
a smaller value to the input filter constant (α), or set a
smaller value to the PV threshold (SH
PV) for auto tuning,
and then check the result for improvement.
6757
<Limit cycle method>
Auto tuning result exceeds proportional gain. (KP=
outside range from 0 to 32767)
<Auto tuning is finished (KP = 32767). → PID operation is
started.>
The variation of the measured value (PV) is small
compared with the output value. Multiply the measured
value (PV) by "10" so that the variation of the measured
value will increase during auto tuning.
6758
<Limit cycle method>
Auto tuning result exceeds integral time.
(T
I = outside range from 0 to 32767)
<Auto tuning is finished (KP = 32767). → PID operation is
started.>
The auto tuning time is longer than necessary.
Increase the difference (ULV - LLV) between the upper
limit and lower limit of the output value for auto tuning, set
a smaller value to the input filter constant (α), or set a
smaller value to the PV threshold (SHPV) for auto tuning,
and then check the result for improvement.
6759
<Limit cycle method>
Auto tuning result exceeds derivative time.
(T
D = outside range from 0 to 32767)
6760 ABS data read from servo sum check error
Check servo wiring and parameter setting. Also check the
ABS instruction.
Error
code
PLC operation at
error occurrence
Contents of error Action