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Checking the Data Carrier Life
MDS Command Execution
Example
1,2,3...
MDS Command
The management area consists of three bytes beginning with the first address
of the area. When the MDS command is executed, the specified number of
overwriting operations is subtracted from the present number and the result is
written to this area. If it is 0 (00
It is necessary to specify the allowable number of overwriting operations
beforehand. This can, in theory, be set to any number up to 16,700,000 but
the specification for the allowable number of overwriting operations for an
EEPROM-type Data Carrier at temperatures of less than 40 ° C is 300,000
(0493E0
) so set to a number less than this. The number of overwriting oper-
H
ations up to the present time is written in the management area as hexadeci-
mal data. The data can also be read using the read command.
If the number of overwriting operations in the management area is already 0,
the hexadecimal data value will not be renewed. In this case, only the warning
will be returned when the MDS command is executed. If the MDS command is
executed with 00
, nothing will be written to the hexadecimal data but the
H
number of overwriting operations up to the present time can be checked.
First address of the area
In the following example, three bytes beginning with address 0010
ified as the management area for overwriting operations.
1. Input 300,000 overwriting operations with WTH100100493E0.
2. Input 5 overwriting operations with MDS1001005.
3. The following indicates that the number of overwriting operations is
300,000. MD76 will be returned to indicate an excessive number of over-
writing operations if MDS1001000 is executed.
), end code 76 will be returned as a warning.
H
Leftmost digit
Middle digit
Three bytes
Rightmost digit
0010
04
H
H
0011
93
H
H
0012
E0
H
H
0010
04
H
H
0011
93
H
H
0012
DB
H
H
Section 5-4
are spec-
H
57
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