Mitsubishi MELSEC QCPU Programming Manual page 86

3 CONFIGURATION OF INSTRUCTIONS
Device range checks are also conducted when index modification is performed.
However, if index modification has been conducted, there will be no error returned if the
initial device number exceeds the relevant device range.
BMOV
BMOV
(c) Because all character string data is of variable length, device range checks are performed.
In cases where the corresponding device range has been exceeded, an operation error will
be returned.
For example, in a case where the data register has been allocated 12 k points, there will be
an error if it exceeds D12287.
Note that an operation error does not occur even if the head device number exceeds the
device range as the result of index modification.
(d) Device range checks are conducted when index modification is performed by direct access
output (DY).
(2) Device data check
Device data checks for the devices used by basic instructions and application instructions in
CPU module are as indicated below:
(a) When using BIN data
• No error is returned even if the operation results in overflow or underflow.
The carry flag does not go on at such times, either.
(b) When using BCD data
1) Each digit is check for BCD value (0/ to 9).
An operation error is returned if individual digits are outside the 0 to 9 (A to F) range.
2) No error is returned even if the operation results in overflow or underflow.
The carry flag does not go on at such times, either.
(c) When using floating decimal point data
Operation errors are returned in the following cases:
• When value of floating decimal point data is 0
• When the absolute value of the floating decimal point data is 1.0 × 2
• When absolute value of floating decimal point data is 1.0 × 2
(d) When using character string data
No data check is conducted.
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MOV K2 Z1
K100 D12285Z1 K2
K100 D12287Z1 K2
$MOV "ABC" D12287
D12287 and D12288 have been indicated here, but because
D12288 does not exist, an operation error is returned.
Because the initial device number is D12289 and that exceeds
the device range, the initial device number is made W0,
the operation is conducted, and no error is returned.
D12287 and D12288 have been indicated here, but because
D12288 does not exist, an operation error is returned.
MELSEC-Q/QnA
-127
or lower
128
or higher
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