Id Tag Memory Error Correction Function - Mitsubishi MELSEC-Q EQ-V680D1 User Manual

5. THINGS YOU NEED TO KNOW BEFORE PROGRAMMING

5.6 ID Tag Memory Error Correction Function

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The ID tag memory error correction function allows you to execute an ID tag data
check and then write five error correction code bytes after the write data using Write
with Error Correction.
The function also allows you to execute a data check and correct a one-bit error using
Read with Error Correction.
Area head
address
Area final
address
Write with Error
Correction is
executed
When a one-bit memory error is corrected with Read with Error Correction, the error
details storage area (Un\G41, Un\G4041) data correction flag (bit 3) turns ON, error
detection (X5, XD) turns ON, a one-bit memory error notification is sent, the data are
corrected, and normal data are stored in the data storage area (Un\G100 to
Un\G1123, Un\G4100 to Un\G5123).
When a memory error of two or more bits is detected, the error details storage area
(Un\G41, Un\G4041) status flag (bit 4) turns ON, error detection (X5, XD) turns ON, a
notification indicating there was a non-correctable memory error is sent, and the read
data are not returned.
Address
0000
H
0001
H
Memory check code (upper)
Memory check code (lower)
Error correction code (upper)
Error correction code (middle)
Error correction code (lower)
Memory check
code calculation
Error correction
range
code calculation range
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