Siemens SIMATIC RF300, Системное руководство

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Figure 7-1 Memory configuration of the RF300 transponders
EEPROM area
The memory configuration of an RF300 transponder always comprises an EEPROM that has 20
bytes for user data (read/write) and a 4-byte unique serial number (UID, read only). For reasons
of standardization, the UID is transferred as an 8 byte value through a read command to address
FFF0 with a length of 8. The unused 4 high bytes are filled with zeros.
Note
Write access
Write access operations with a length that is not divisible by four without a remainder are
acknowledged with an address error.
Note
Write speed
The EEPROM user memory (address FF00-FF13, or FF80-FF90) requires significantly more time
for writing (approx. 11 ms/byte) than the high-speed FRAM memory. For time-critical
applications with write functions, it is advisable to use FRAM transponders (e.g. RF330T, RF340T,
RF350T, RF360T, RF370T, RF380T).
FRAM area
Except for the RF320T, all RF300 transponders have a fast FRAM memory (8, 32, 64 or 256 KB).
In the case of RF300 transponders with FRAM memory, the data carrier initialization command
(INIT) is only effective on this memory area but not on the EEPROM area (FF00-FF13).
OTP area
The EEPROM memory area (address FF00-FF13) can also be used as a so-called "OTP" memory
(One Time Programmable). The 5 block addresses FF80, FF84, FF88, FF8C and FF90 are used for
this purpose. A write command to this block address with a valid length (4, 8, 12, 16, 20
depending on the block address) protects the written data from subsequent overwriting.
Note
Seamless use of the OTP area
When the OTP area is used, it must be ensured that the blocks are used starting from Block 0
consecutively.
Examples:
• 3 blocks (with write command), Block 0, 1, 2 (FF80, length = 12): valid
• 2 blocks (consecutive), Block 0 (FF80, length =4), Block 1 (FF84, length = 4): valid
• 2 blocks (consecutive), Block 0 (FF80, length =4), Block 2 (FF88, length = 4): Invalid
• 1 Block, Block 4 (FF90, length = 4): Invalid
RF300 transponder
7.1 Memory configuration of the RF300 transponders
SIMATIC RF300
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System Manual, 02/2021, C79000-G8976-C345-09