Mitsubishi Electric MELSEC iQ-R Series - Page 1444

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14 REDUNDANT SYSTEM INSTRUCTIONS
14.1 System Switching
• The error completion device specified by (d) turns off when the systems were switched successfully, and turns on when the
system switching operation failed. When there is a switching disable cause, 16 (System switching request by using the
SP.CONTSW instruction) is stored in SD1643 of the CPU module in the control system. The corresponding disable cause
number is stored in SD1644. For the disable cause number stored in SD1644, refer to the following.
 MELSEC iQ-R CPU Module User's Manual (Application)
Precautions
• To execute the instruction, turn on (enabled) SM1646. If SM1646 is off (disabled), the systems cannot be switched.
• Even if SM1646 is turned off after execution of the instruction and before the END processing that performs the system
switching operation, the systems can be switched.
• When the systems are switched by using the instruction
• When SM1646 is off at execution of the instruction
END
ON
OFF
END
System A
System B
Program executed
Program stopped
Execution of the instruction
Control system Standby system
System
switching
SP.CONTSW instruction
Standby system
Program executed
Control system
Program stopped
Error completion
device
END
ON
OFF
END
System A
System B
Program executed Program executed
Program stopped
Execution of the instruction
Control system
SP.CONTSW instruction
Standby system
Error completion
device