Control Number Of Writes - Mitsubishi MELSEC-Q EQ-V680D1 User Manual

6. HOW TO COMMUNICATE WITH ID TAGS

6.2.9 Control number of writes

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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
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
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 is added to the three bytes from the address 0010
H
Number of Writes (Addition)
Buffer memory
Address
b15
Option
Un\G5
00 12
H
ID tag
Before
b0 b7
execution
0010 01
H
23
0011
H
45
0012
H
b0 b7
0010
H H
0011
H
H
0012
H
H
, the data of
H
, the data of
H
using Control
H
ID tag
After
b0
execution
01
H
23
H
57
H
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