Write Protect Function - Omron V600-CA8A-V Series Operation Manual

Data Carrier Memory Map
Example

3-2-3 Write Protect Function

Setting Write Protect Function
Example 1
20
Note 1. The last two digits of the year is used. For example, 92 for 1992.
2. The month is represented by two digits. For example, 03 for March and 10
for October.
In the case of September 1992, the bits are as follows:
Address
7
0000 0
0
0001
1
9
Note A DC with a memory capacity of 256 bytes or less does not have a production
date (month and year) area. The first address of such a DC is a write protect
area.
The write protect function protects important data stored in the memory of the
Data Carrier, such as product number and model, from inadvertent write access.
With this function, the data up to a specified memory address can be protected.
The setting of page 0 is necessary because the address is set to 0000 or 0002 to
0005.
It is recommended that important data be write-protected as follows:
The write protect function is set in address 0000 of the Data Carrier's memory.
The most significant bit of address 0000 determines whether or not the write pro-
tect function is in effect.
Address
7
0000 YES/
NO
Write protect execution bit (most significant bit of address 0000)
1: Write-protected
0: Not write-protected
The end address can be set between 00 and 7F. Setting the address to 00 pro-
tects all bytes from 0001 through 00FD. Setting the address to a value from 01 to
7F protects all bytes from 0001 through the specified address. It is not possible
to specify an end address between 0080 and 00FF.
Note 1. Address 0000 cannot be write-protected.
2. Address 0001 is always the starting address of the write-protect area. Im-
portant data that needs to be protected should be input from 0001 on.
To protect addresses 0001 through 0012:
Address
0000
É É É É É É
É É É É É É
É É É É É É
0012
00FD
Address
0000 1
6 5 4
0 0 0
0 0 1
6 5 4
Last 2 digits of end address
Write-protected area
Higher digits
0 0 1 0
9
Section
Bit
3 2 1
1 0 0
9
0 0 1
2
Bit
3 2 1
Lower digits
0 1 0
2
3-2
0
1
0
0