RFID Tag Memory Banks are divided into read-only and read-write. That is also what is found in the Gen 2 RFID Tags.
RFID Tag Memory Banks on Gen 2 RFID Tags have chips that can write data indicating that they provide a storage area for the user.
Each different chip will have a different storage area structure. Likewise with the chips used in Gen 2 RFID Tags.
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This article will help you to get to know the tag memory bank contained in the Gen 2 RFID Tags which many people may not know about.
Table of Contents
The Type of Memory on Gen 2 RFID Tags
1. TID Memory
TID (Tag Identifier) memory is specifically designated for storing the unique identification number of an RFID tag. This identifier is assigned during manufacturing and is generally not editable.
The initial portion of the TID indicates the manufacturer, with each company having its own distinct set of codes.
Typically, the TID is globally unique. Since the TID provides a built-in unique identifier, it can be used to track objects or individuals without the need for additional programming, making it a straightforward solution.
2. EPC Memory
EPC (Electronic Product Code) memory is intended for storing a unique identifier based on the GS1 standard, which is widely used for product identification in retail. However, it can also be programmed with custom codes, such as service numbers, inventory numbers, or serial numbers.
This memory bank has a minimum of 96 bits of writable storage, which is sufficient for many applications. Some RFID tags allow extra space from user memory to be allocated to EPC memory.
As the first writable memory bank, its factory settings vary depending on the chip manufacturer—some pre-program it with a standard or pseudo-random code, while others leave it blank. If using the pre-set EPC, it is important to verify how it is configured.
3. User Memory
For applications requiring additional storage beyond what EPC memory offers, some RFID chips include user memory. The size of this memory is not standardized and varies by tag.
A well-known example is the Monza 4QT chip, which provides 512 bits of user memory. However, other RFID tags offer significantly larger storage capacities, reaching up to 4 or even 8 kbit. This memory bank is the second writable area in Gen 2 RFID chips.
4. Reserved Memory
Reserved memory is designated for security-related data, specifically the kill password and access password, each 32 bits in length. By default, both passwords are set to ‘0’, meaning they are inactive.
The kill password permanently disables the tag, rendering it unusable. While not commonly used, this function is valuable in retail, where RFID tags are often deactivated at checkout.
The access password controls the tag’s write permissions and can place it in one of four states:
- Unlocked (fully accessible)
- Perma-unlocked (cannot be locked again)
- Locked (write access restricted)
- Perma-locked (permanently locked, cannot be unlocked)
Reserved memory is unique in that it can be locked for both reading and writing, whereas other memory types can only be locked for writing. This means that even if an RFID tag is locked, its data remains readable.
Those are the four types of memory found in Gen 2 RFID Tags that not many people know about. Hopefully, this article helps make you familiar with the tag memory bank found in Gen 2 RFID Tags.
