Troubleshooting; Error Codes - Mitsubishi Electric FX3G User Manual

FX /FX /FX /FX /FX
3S 3G 3GC 3U
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 < PV)
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
M-28
PLC User's Manual - Analog Control Edition
3UC
Error description
≤ 0)
) (T
S S
) (K < 0)
P P
) (T < 0)
I I
)
D
)
D
) (T < 0)
D D
) ≤ Operation cycle
S
<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.>
• 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.
Confirm the measured value and target value, and then execute
auto-tuning again.
<Auto-tuning is forced to finish. → PID operation does 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
Action
)
S