Mitsubishi Electric MELSEC iQ-R Series - Page 1210

1208
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 conversion processing (5)
The output value (BW) is calculated from the following expression.
■Loop stop processing (6)
The following processing is performed according to the SPA status of the alarm detection (ALM).
■Hold processing (7)
This processing specifies whether to hold the output value (BW) by the S.OUT1 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
SPA status Processing details
1 The loop stops. When the loop stops, the following operations are performed and the S.OUT1 instruction ends.
• The last output value (BW) is held.
• 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), (s2), or (d2) is a subnormal number or NaN (not a number).
3403H An overflow has occurred.
T1>MH,
©T
I
<=1
I
©T
MVP=(
)(MH-T)+T
T1<MH,
©T
I
<=1
I
©T
MVP=(
)(ML-T)+T
BW= ×MV+NMIN
100
NMAX-NMIN