Mitsubishi Electric MELSEC iQ-R-R6SFM - Instructions that Affect the Status of Another Instruction When Executed; Instruction that Causes Different Operation Results between the Control System and Standby System

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29 PRECAUTIONS ON PROGRAMMING
29.1 Instructions Not Available in Redundant System
Instructions that affect the status of another instruction when
executed
When one of the following instructions is executed and the status of another instruction changes, the new status will not be
tracked to the other system. When the system switching is performed during execution of an instruction, execute the
instruction again as required.
Instruction that causes different operation results between the
control system and standby system
The following describes the instruction that causes different operation results in both systems after system switching.
PID control instruction
When using the following PID control instructions, include the number of device points used by the systems in tracking target
data. Otherwise, the instructions cause different operation results between the control system and standby system after
system switching.
n: Total number of loops
Ex.
When the number of loops is eight, the PIDINITP instruction needs 2 + 8  10 = 82 words and the PIDCONTP instruction
needs 10 + 8  18 = 154 words. Thus, include D1000 to D1081 and D1100 to D1253 in tracking target data.
Classification Instruction symbol
Program execution control instructions Disabling interrupt programs DI
Enabling interrupt programs EI
Disabling interrupt programs with specified priority or
lower
DI
Interrupt program mask IMASK
Disabling/enabling the specified interrupt pointer SIMASK
File register operation instructions Switching the file register block number RSET(P)
Changing the file register file name QDRSET(P)
Timing check instruction Generating timing pulses DUTY
Classification Instruction symbol Number of device points used
PID control instructions (Inexact
differential)
Registering the PID control data to
the CPU module
S(P).PIDINIT 2 + n  4
PID operation S(P).PIDCONT 10 + n  23
PID control instructions (Exact
differential)
Registering the PID control data to
the CPU module
PIDINIT(P) 2 + n  10
PID operation PIDCONT(P) 10 + n  18