Mitsubishi Electric MELSEC iQ-R Series - Page 1224

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11 PROCESS CONTROL INSTRUCTIONS
11.2 I/O Control Instructions
■Reset windup (4)
If the manipulated value (MV) goes beyond the upper or lower limit, the following operation is performed to return it to the
upper or lower limit and enable immediate response when the deviation is inverted. However, when the integral constant (I) is
0, reset windup processing is not performed.
■Output ON time conversion processing (5)
The following processing is performed by output ON time conversion processing.
■Output conversion processing (6)
The following processing is performed by output conversion processing.
■Loop stop processing (7)
The following processing is performed according to the SPA status of the alarm detection (ALM).
■Hold processing (8)
This processing specifies whether to hold the output value by the S.DUTY instruction when a sensor error occurs (detected by
the S.IN instruction). The hold processing is performed when the value is determined as RUN by "Loop Stop Determination".
SM817 is used to specify whether to hold the manipulated value (MV) when a sensor error occurs.
• SM817 = OFF: Do not hold the manipulated value (MV).
• SM817 = ON: Hold the manipulated value (MV).
Operation error
Condition Operational expression
Condition Processing details
The control output cycle (CTDUTY) has been reached. The output ON counter is calculated using the following expression. The output counter is
cleared to 0 at this time.
The output ON counter is rounded off to the nearest whole number.
The control output cycle (CTDUTY) has not been reached. The output counter is incremented by, 1 and "output conversion processing (6)" is performed.
Condition BW1
Output counter < Output ON counter 1
Output counter  Output ON counter 0
SPA status Processing details
1 The loop stops. When the loop stops, the following operations are performed and the S.DUTY instruction ends.
• The output bit (BW1) is output at the last ON/OFF rate.
• The DMLA, MHA, and DLA of the alarm detection (ALM) are set to 0.
• The MHA2 and MLA2 of the alarm detection 2 (ALM2) are set to 0.
• The control mode (MODE) is set to MAN.
• The alarm bits (BB1, BB2, BB3, and BB4) are set to 0.
0 The loop runs and "mode determination (1)" is performed.
Error code
(SD0)
Description
3400H An invalid operation (such as division by zero) is performed.
3402H The value specified by (s1) or (d2) is a subnormal number or NaN (not a number).
3403H An overflow has occurred.
3405H Control output cycle (CTDUTY) < 0
The execution cycle (T) setting is less than 0.
(Control output cycle (CTDUTY)execution cycle (T)) > 32767
T1>MH,
©T
I
<=1
I
©T
MVP=(
)(MH-T)+T
T1<MH,
©T
I
<=1
I
©T
MVP=(
)(ML-T)+T
CTDUTY
100
1
×MV×
©T