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SECTION 5
RF Ta
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L
if
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Chec
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RFID System
User's Manual
SECTION 5
ID Sensor Unit Functions
RF Tag Service Life Check
The Number of Writes Control command can be used to determine whether the RF Tag write limit has been
exceeded. Detecting when the write life has been exceeded for an RF Tag is performed by using the Number
of Writes Control command that determines whether the write count (100,000 times or a user specified value)
for an RF Tag has been exceeded.
There are two ways to manage the number of writes. One is to add to the number of writes and then detect
when the total exceeds 100,000 writes. The other is to subtract from a user-specified number of writes and
then detect whether the write count has been exceeded.
Number of Writes Control 1 (Life Control = Preset Number of Writes)
The Number of Writes Control Area consists of 3 bytes from the
start address. The Number of Writes Control command is
executed with an Add specification. The specified numbers of
writes are added and the total is written to the control area.
When the value in the number of writes control area exceeds
the preset number of writes (100,000 writes) (0186A0 hex), the
Status Flag (CIO n+8, bit 04) in the Results Information turns
ON. If the value in the control area already exceeds 100,000
writes, the value will not be changed.
• Application Method
The life of the RF Tag can be managed by updating the number of writes value when data is written to
the address most frequently written. (The life of EEPROM RF Tags is 100,000 writes for any one data
block (8 bytes), so the number of writes must be counted for the address that is written most
frequently.) It is also possible to confirm the number of writes without updating the number of writes
value.
Area start
address
Upper digit
Middle digit
Lower digit
3 bytes
Data written
No. of writes updated/
life checked
Life checked
Write stage
Life confirmation
stage
Summary of Contents for CJ1W-V680C11
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