5-5
Section
Checking Function of the Data Carrier’s Memory
56
In the following example, three bytes beginning with address 0010
H
is specified
as the management area for overwriting operations.
1, 2, 3...
1. Clear the management area first with WTH10010000000.
00
H
00
H
00
H
0010
H
0011
H
0012
H
2. Input 4 overwriting operations with MDL1001004.
00
H
00
H
04
H
0010
H
0011
H
0012
H
3. Input 5 as the next number of overwriting operations with MDL1001005
make the total overwriting operations 9.
00
H
00
H
09
H
0010
H
0011
H
0012
H
4. The following indicates that the number of overwriting operations is
100,000. MD76 will be returned to indicate that an excessive number of
overwriting operations will result if MDL1001000 is executed.
01
H
86
H
A0
H
0010
H
0011
H
0012
H
5-5
Checking Function of the Data Carrier’s Memory
A Data Carrier memory check is possible by executing the data check command
MD. CRC (Cyclic Redundancy Check) code calculation, data writing, and data
collation are possible in a check block specified by the user. A CRC code is cal-
culated with the generating function X
16
+ X
12
+ X
5
+1.
Command Format
Processing specification
(C: Collation; K: Calculation)
Read/Write head word (fixed to 1)
Check block first address (0000
H
to FFFD
H
)
Specify a hexadecimal value (03
H
, 04
H
,..., FE
H
, FF
H
, 00
H
)
for the number of overwriting operations to be added.
00
H
means 256 bytes.
M
D
C/K
1
X
X
X
X
X
X
CR
∗
MDL Command Execution
Example