Slmp Communication - Mitsubishi Electric MELSEC iQ-R Series User Manual

26.10

SLMP Communication

The SLMP frame send instruction (SP.SLMPSND) performs communications using different IP addresses in the system A and
the system B.
The following describes the precautions on SLMP communications.
System switching
There are the following notes when the system IP address matching function is not used.
■Re-setting of the connection destination
When the relay CPU module is in the communication-disabled state (power-off, reset, or tracking cable disconnection) at
system switching, the connection destination needs to be set again for SLMP communications.
■Re-execution of the write command
When "Control System" or "Standby System" has been selected in the transfer setup and the systems are switched, a target
system mismatch is detected by a command issued during the system switching, and a communication error occurs. If a
communication error occurs while a data write command is being issued, the data write command needs to be issued for the
new control system.
Remote operation
If a remote operation command is executed, the CPU modules enter different operating statuses and thus systems cannot be
switched.
Communicating with other systems
For SLMP communications via the built-in Ethernet port of the CPU module, when communications are performed to the other
system that cannot respond (power-off, reset, or tracking cable disconnection), a timeout error may occur.
External device
26 REDUNDANT FUNCTION
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26.10 SLMP Communication
Own system The other system