5 - 16
5 - 16
5. THINGS YOU NEED TO KNOW BEFORE PROGRAMMING
5.4 ID Tag Number of Writes Management Function (EEPROM Type Only)
Whether or not the ID tag number of writes has been exceeded can be assessed using
the Manage Number of Writes command.
The write life is detected by assessing whether or not the ID tag number of writes (100,000
or an arbitrary number) has been exceeded using the Manage Number of Writes
command.
There are two methods for managing the number of writes: adding the number of
writes and assessing whether or not the number exceeds the preset write life of
100,000, or subtracting the number of writes from the write life specified by the user
and assessing whether the number of writes has been exceeded.
5.4.1 Manage Number of Writes 1 (Write life = Preset number of writes)
The three bytes from the ID tag head address serve as the number of writes
management area.
When the sum of the number of writes is written in this area and the value is greater
than or equal to 100,000 (0186A0
H
), the number of writes is exceeded, the status flag
(bit 4) of the error details storage area (Un
\
G41, Un
\
G4041) turns ON, and error
detection (X5, XD) turns ON.
When the data of the management area already exceeds 100,000, the value of the
management area is not updated.
ID tag
3 bytes
Area head
address
Upper digit
Middle digit
Lower digit
(1) Method of use
The write life of an EEPROM-type ID tag is 100,000 for every block (8 bytes),
requiring the number of writes of the address within the block in which data are
most frequently written to be counted.
When data are written in the address in which data are most frequently written, the
number of writes is updated, enabling verification of the write life.
The number of writes can also be verified without updating the number of writes.
Write stage
Life verification
stage
Write data
Update number
of writes
Verify life
