Mitsubishi Electric Melsec Q Series Programming Manual page 184

3 MOTION DEDICATED PLC INSTRUCTION
Device No. Name
Block information using Multiple
CPU high-speed transmission
SM796
dedicated instruction
(For CPU No.1)
Block information using Multiple
CPU high-speed transmission
SM797
dedicated instruction
(For CPU No.2)
Block information using Multiple
CPU high-speed transmission
SM798
dedicated instruction
(For CPU No.3)
Block information using Multiple
CPU high-speed transmission
SM799
dedicated instruction
(For CPU No.4)
(b) Permissible number of executions for dedicated instructions on Multiple CPU
high-speed transmission
When the number of blocks being used to communicate with each CPU in
the Multiple CPU dedicated instruction transmission area exceeds the set
value for maximum number of blocks used for the Multiple CPU high-speed
transmission dedicated instruction setting (special registers SD796 to
SD799 of PLC CPU), the system enters a state where the Motion dedicated
PLC instruction is not accepted (permissible number of executions
exceeded state). At the time of Motion dedicated instruction execution
towards the target CPU, an abnormal complete status "0010H" is set in the
complete status device. If the complete device is omitted, no operation
occurs at all.
An interlock can be created using block information using Multiple CPU
high-speed transmission dedicated instruction (SM796 to SM799 of the PLC
CPU) so that the permissible number of executions is not exceeded.
• Special relay of PLC CPU
Meaning
OFF: Block is secured
ON : Block set by SD796
cannot be secured
OFF: Block is secured
ON : Block set by SD797
cannot be secured
OFF: Block is secured
ON : Block set by SD798
cannot be secured
OFF: Block is secured
ON : Block set by SD799
cannot be secured
Explanation
Turns ON when the number of the
remaining blocks of the dedicated
instruction transmission area used for the
Multiple CPU high-speed transmission
dedicated instruction is less than the
number of blocks specified by "SD796 to
SD799".
Turns ON at instruction execution. Turns
OFF when empty area exists at END
processing.
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Set by
System
(When
instruction/
END processing
executed)