Mitsubishi Electric MELSEC FX3U Programming Manual page 947

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Error PLC operation at
code error occurrence
Operation error [M8067(D8067)]
6742
6743
6744
6745
6746
6747
6748
6749
6750
Continues
operation
6751
6752
6753
6754
6755
Contents of error
Variation of measured value exceeds limit.
( PV < −32768 or +32767 <
Deviation exceeds limit.
(EV < −32768 or +32767 < EV)
Integral result exceeds limit.
(Outside range from −32768 to +32767)
Derivative value exceeds limit due to derivative
gain (K ).
D
Derivative result exceeds limit.
(Outside range from −32768 to +32767)
PID operation result exceeds limit.
(Outside range from −32768 to +32767)
PID output upper limit set value < PID output lower
limit set value.
Abnormal PID input variation alarm set value or
output variation alarm set value (Set value < 0)
<Step response method>
Improper auto tuning result
<Step response method>
Auto tuning operation direction mismatch
<Step response method>
Improper auto tuning operation
<Limit cycle method>
Abnormal output set value for auto tuning
[ULV (upper limit) ≤ LLV (lower limit)]
<Limit cycle method>
Abnormal PV threshold (hysteresis) set value for
auto tuning (SH < 0)
PV
<Limit cycle method>
Abnormal auto tuning transfer status
(Data of device controlling transfer status is
abnormally overwritten.)
38 Error Check Method and Error Code List
PV)
<PID operation is continued.>
The operation is continued with each parameter set
to the maximum and minimum value.
<Transpose of output upper limit value and output
lower limit value. → PID operation is continued.>
Verify that the target setting contents are correct.
<Alarm output is not given. → PID operation is
continued.>
Verify that the target setting contents are correct.
<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.
<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.
<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.
<Auto tuning is forcibly finished. → PID operation is
not started.>
Check whether the target setting contents are
correct.
<Auto tuning is forcibly finished. → PID operation is
not started.>
Ensure that devices occupied by PID instruction are
not overwritten in the program.
38.4 Error Code List and Action
Action
945
31
32
33
34
35
36
37
38
A
B