Precautions On Programming; Instructions Not Available In Redundant System - Mitsubishi Electric MELSEC iQ-R Series User Manual

26.11

Precautions on Programming

This section describes the precautions on programming for a redundant system.

Instructions not available in redundant system

This section describes the instructions not available in a redundant system.
Instructions that cause stop errors
Do not use the following instructions when the redundant system is in backup mode. Doing so causes an error when the
operating status of the CPU module is changed from STOP to RUN.
Classification
Special counter instructions
Special timer instructions
Shortcut control instruction
Ramp signal instruction
Pulse related instructions
Matrix input instruction
Multiple CPU dedicated instructions
Instructions that need to be executed again in a new control system
For an instruction that requires several scans for completing the processing, the instruction will be continuously executed
when the system switching is performed during execution of the instruction. When a completion device has been used in an
execution program of the control system, the completion device will not turn on even though the instruction is completed after
the system switching from the control system to the standby system. However, the completion device will turn on after the
system switching from the control system to the standby system and then to the control system again. Note that the
completion status of the completion device is not reflected to the tracking device. When the system switching is performed
during execution of an instruction, execute the instruction again as required.
Classification
Data processing instructions
Reading/writing data instructions
Open/close processing instructions
Socket communications instructions
SLMP frame send instruction
File transfer function instruction
Module dedicated instructions
For some instructions, an error will occur if an instruction is executed during execution of the same instruction. For the
operation for each instruction that is executed again during execution of the same instruction, refer to the following.
 MELSEC iQ-R Programming Manual (CPU Module Instructions, Standard Functions/Function Blocks)
 MELSEC iQ-R Programming Manual (Module Dedicated Instructions)
Counting up or down the current value (1-phase input)
Counting up or down the current value (2-phase input)
Teaching timer
Special function timer
Rotary table shortest direction control
Ramp signal
Measuring the density of pulses
Outputting pulses at regular intervals
Performing the pulse width modulation
Matrix input
Reading device data from another CPU module
Writing device data to another CPU module
Instruction symbol
SORTD(_U), DSORTD(_U)
SP.DEVST, SP.FREAD, SP.FWRITE
SP.SOCOPEN, SP.SOCCLOSE
SP.SOCRCV, S.SOCRCVS, SP.SOCSND, SP.SOCCINF, SP.SOCCSET,
SP.SOCRMODE, S(P).SOCRDATA
SP.SLMPSND
SP.FTPPUT, SP.FTPGET
Instructions that require several scans for completing processing
Instruction symbol
UDCNT1
UDCNT2
TTMR
STMR
ROTC
RAMPQ
SPD
PLSY
PWM
MTR
D.DDRD
DP.DDRD
M.DDRD
MP.DDRD
D.DDWR
DP.DDWR
M.DDWR
MP.DDWR
26 REDUNDANT FUNCTION
26.11 Precautions on Programming
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