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61
Write Protection
Section 5-5
5-5
Write Protection
The write protection function is provided so that product model numbers and
other important product information stored in the Data Carrier can be pro-
tected from being lost though careless write operations. We recommend that
write protection be set after important data has been written.
5-5-1
EEPROM (Battery-free) Data Carriers
Setting Write Protection
If the write protection end address is written to address 0000 (hex) of the Data
Carrier, address 0001 (hex) to the specified end address will be write-pro-
tected. Write protection can be enabled and disabled by setting bit 7 of
address 0000 (hex).
• Write Protection Bit
• Write Protection Setting Range
Note
1.
Address 00 (hex) cannot be write-protected.
2.
Addresses 80 (hex) to FD (hex) cannot be set as the end address.
3.
If the end address is set to 00 (hex), all addressed from address 01 (hex)
to FF (hex) will be write-protected.
4.
Write any data to be write-protected starting at address 0001 (hex). The
start address for write protection is 0001 (hex) fixed.
Write Protection Settings
Example for Data Carrier
with a Memory Capacity of
254 Bytes
The following settings will write-protect addresses 0001 (hex) to 0012 (hex).
Address
Bit No.
7
6
5
4
3
2
1
0
0000
Pro-
tected
/Not
pro-
tected
End address
Address 0000 (hex), bit 7
Description
1
Enable write protection.
0
Disable write protection.
Address
Write protection setting range
Start address
Always 01 (hex)
End address
00 (hex), or 01 (hex) to 7F (hex)
Address
Bit No.
7
6
5
4
3
2
1
0
0000
1
0
0
1
0
0
1
0
9
2
Address (hex)
0000
0001
0012
00FD
Write-protected
area
Summary of Contents for CJ - 12-2004
Page 2: ...SYSMAC CS CJ Series ID Sensor Units Operation Manual Revised December 2004...
Page 3: ...iv...
Page 11: ...xii...
Page 55: ...36 Connections and Wiring Section 3 4...
Page 69: ...50 I O Data Allocations Section 4 3...
Page 91: ...72 Data Check Section 5 7...
Page 141: ...122 Sample Programming Appendix B...
Page 147: ...128 Revision History...