Mitsubishi Electric MELSEC-Q/L Programming Manual page 113

Device range check
Device range checks for the devices used by basic instructions and application instructions in CPU module are as indicated
below:
■Instructions for specified each device, including MOV and DMOV
• For the Basic model QCPU, High Performance model QCPU, Process CPU, and Redundant CPU.
The device range is not checked. In cases where the corresponding device range is exceeded, data is written to other
*1
devices.
For example, in a case where the data register has been allocated 12K points, there will be no error even if it exceeds
D12287.
DMOV K100 D12287
Device range checks are not conducted also in cases where indexing is being performed.
In cases where the corresponding device range is exceeded as the result of performing indexing, data is written to other
*1
devices.
*1 For the assignment order of internal user devices, refer to Page 113 Character string data.
• Universal model QCPU and LCPU
The device range is checked. When the device number is outside the device range, an operation error occurs.
For example, when 12K points are assigned to a data register, an error occurs if the device number of the data register
exceeds D12287.
DMOV K100 D12287
The device range is checked even though indexing is executed.
With changing the settings of the PLC parameter, the device range is not checked.
*2 For the method that the device range check is disabled when the index modification is specified, refer to the User's Manual (Function
Explanation, Program Fundamentals) for the CPU module used.
This designates D12287 and D12288 as the
target devices for executing the DMOV instruction.
However, since D12288 does not exist,
data in another device is corrupted.
This designates D12287 and D12288 as the
target devices for executing the DMOV instruction.
However, since D12288 does not exist,
data in another device is corrupted.
3.6 Cautions on Programming (Operation Errors)
*2
3 CONFIGURATION OF INSTRUCTIONS
3
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