Mitsubishi MELSEC-Q series Programming Manual page 81

(4) Reset windup
If the manipulated value (MV) exceeds the upper/lower limit value, the following operation is performed to return it to the
upper/lower limit value and enable immediate response when the deviation is inverted.
However, when the integral constant (T1) is 0, the reset windup processing is not performed.
Condition
When T1 > MH,
T
When T1 < ML,
T
(5) Output ON time conversion processing
(a) When the control output cycle (CTDUTY) is reached, the output ON counter is calculated with the following
expression. At this time, the output counter is cleared (to 0).
Output ON Counter
The output ON counter rounds off a fraction to no decimal places.
(b) When the control output cycle (CTDUTY) is not reached, the output counter is incremented by 1 and "(6) Output
conversion processing" is performed.
(6) Output conversion processing
In the output conversion processing, the following processing is performed.
Condition
Output counter < output ON counter
Output counter output ON counter
(7) Loop stop processing
(a) Setting 1 in SPA of the alarm detection (ALM) selects a loop stop.
A loop stop performs the following processing and terminates the S.DUTY instruction.
1) BW is output at the last ON/OFF rate.
2) DMLA, MHA and MLA of the alarm detection (ALM) are turned to 0.
3) MHA2 and MLA2 of the alarm detection 2 (ALM2) are turned to 0.
4) The operation mode (MODE) is changed to MAN.
5) BB1 to BB4 of BB are turned to 0.
(b) Setting 0 in SPA of the alarm detection (ALM) selects a loop run.
A loop run performs "(1) Mode judgment".
(8) Hold processing
Used to specify whether the output value will be held or not by the S. DUTY instruction at sensor error occurrence
(detected by the S.IN instruction).
A hold processing is performed when the value is determined as RUN at "Loop stop judgement".
Use SM1501 to select whether the manipulated value (MV) will be held or not at sensor alarm occurrence.
• SM1501 = OFF: Manipulated value (MV) will not be held.
Operation expression
T
T
MVP (MH T)
1
T
I
I
T
T
MVP (ML T)
1
T
I
I
CTDUTY 1
MV
100
T
T
T
BW
1 (ON)
0 (OFF)
S.DUTY
1
2
3
4
4
6
7
8
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