6 - 10
6 - 10
6. HOW TO COMMUNICATE WITH ID TAGS
6.2.9 Control number of writes
The Control Number of Writes command adds (subtracts) specified data targeting the
three bytes from the address specified in the head address specification area (Un
\
G3,
Un
\
G4003), and writes the calculation result to the ID tag.
The data for the addition (subtraction) operation are stored in the command option
specification area (Un
\
G5, Un
\
G4005).
For details of the number of writes control function, refer to Section 5.4, “ID Tag Number
of Writes Control Function (EEPROM Type Only)”.
(1) Addition (write life = Fixed to 100,000)
When the processing specification area (Un
\
G2, Un
\
G4002) is 0000
H
, the data of
the check start address are added in an amount equivalent to the number of updates.
When the addition result reaches 100,000 or greater, the number of writes is
regarded as 100,000, the status flag (bit 4) of the error details storage area
(Un
\
G41, Un
\
G4041) turns ON, and error detection (X5, XD) turns ON.
(2) Subtraction (write life = arbitrary number)
When the processing specification area (Un
\
G2, Un
\
G4002) is 0001
H
, the data of
the check start address are subtracted in an amount equivalent to the number of
updates.
When the subtraction result reaches 0 or less, the number of writes is regarded as 0,
the status flag (bit 4) of the error details storage area (Un
\
G41, Un
\
G4041) turns
ON, and error detection (X5, XD) turns ON.
(3) Example of use
(a) When 0012
H
is added to the three bytes from the address 0010
H
using Control
Number of Writes (Addition)
Option
Before
execution
After
execution
b15
b0
b7
b0
01
H
23
H
45
H
00 12
H
0010
H
0012
H
0011
H
b7
b0
01
H
23
H
57
H
0010
H
0012
H
0011
H
Un\G5
Buffer memory
Address
ID tag
ID tag
