Troubleshooting; Error Codes - Mitsubishi MELSEC-F FX3U Series User Manual

FX /FX Series PLC User's Manual - Analog Control Edition
3U 3UC
PID Instruction (FNC 88)
6.

Troubleshooting

6.1

Error Codes

When an error occurs in the set value of a control parameter or the data acquired during the PID operation,
the operation error flag M8067 turns ON, and a corresponding error code is stored in D8067.
Error
code
6730
Incorrect sampling time (T
Incorrect input filter constant (α)
6732
(α < 0 or 100 ≤ α)
6733
Incorrect proportional gain (K
6734
Incorrect integral time (T
Incorrect derivative gain (K
6735
< 0 or 201 ≤ K
(K
D
6736
Incorrect derivative time (T
6740
Sampling time (T
Variation of measured value exceeds limit.
6742
( PV < −32768 or +32767 <
Deviation exceeds limit.
6743
(EV < −32768 or +32767 < EV)
Integral result exceeds limit.
6744
(Out of range from −32768 to +32767)
Derivative value exceeds limit due to derivative gain
6745
(K ).
D
Derivative result exceeds limit.
6746
(Out of range from −32768 to +32767)
PID operation result exceeds limit.
6747
(Out of range from −32768 to +32767)
PID output upper limit set value < PID output lower limit
6748
set value
Abnormal PID input variation alarm set value or output
6749
variation alarm set value (Set value < 0)
<Step response method>
6750
Improper auto tuning result
<Step response method>
6751
Auto tuning operation direction mismatch
G-28
Error description
≤ 0)
) (T
S S
) (K < 0)
P P
) (T < 0)
I I
)
D
)
D
) (T < 0)
D D
) ≤ Operation cycle
S
PV)
Action
<PID operation is stopped.>
A data error has occurred in the set value in a control parameter
or in the middle of PID operation.
Check the parameters.
<Auto tuning is continued.>
The operation is continued in the condition "sampling time (T
= cyclic time (operation cycle)."
<PID operation is continued.>
The operation is continued with each parameter set to the
maximum or minimum value.
<Output upper limit value and output lower limit value are
exchanged for each other. → PID operation is continued.>
Check whether the target settings are correct.
<Alarm output is not given. → PID operation is continued.>
Check whether the target settings are correct.
<Auto tuning is finished. → PID operation is started.>
• When auto tuning was started, the difference between the
measured value and the target value was 150 or less.
• When auto tuning was started, the difference between the
measured value and the target value was 1/3 or more.
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 measured value, and then execute auto
tuning again.
6 Troubleshooting
6.1 Error Codes
)
S