Omron V600 Series Operation Manual page 24

Data Carrier Memory Map
3-2-2 Production Date Format
Production Date Control Area
Example
3-2-3 Write Protect Function
Memory of 256 Bytes or Less
Setting Write Protect FunctionThe write protect function is set in address 0000 of the Data Carrier's memory.
22
The production date format is valid for a DC with a memory capacity of more than
256 bytes.
For checking the life of the DC battery, the manufacturer registers the production
date in the first two bytes of the memory area immediately prior to shipping the
DC from the factory. Data can be read from this area, but cannot be written to it. If
a write operation to this area is attempted by mistake, an error message, "7D,"
will be issued.
Address
7
0000 Month, first digit
0001 Year, first digit
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. It
is recommended that important data be write-protected as follows:
The most significant bit (MSB) of address 0000 determines whether or not the
write protect 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 00FF. 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.
Bit
6 5 4
Bit
6 5 4
0 0 0
0 0 0
Bit
6 5 4
Last 2 digits of end address
Section
3 2 1
Month, second digit
Year, second digit
3 2 1
1 0 0
9
1 0 0
2
3 2 1
3-2
0
0
1
1
0