What data ranges are available within RFID Tag?
CommonUHF RFIDThe tag chip divides different storage areas according to the protocol, also known as the Memory Bank. The project often encounters Reserved, EPC, TID and User Memory, but the exact capacity and functionality must be based on the chip data manual.
- Reserved: usually used for access to controlled data such as passwords, destruction of passwords, as confirmed by chip specifications
- EPC: Commonly used to save business identification codes
- TID: used to provide information on identity and manufacture of label chips
- User Memory: additional user data space provided by selected chips
Not every label provides a User Memory of the same capacity, and some chips do not have additional user areas for the project. Even if the chip is supported, it is necessary to consider reading and writing time, privileges and business maintenance.
What's the EPC?
The EPC area usually carries out the identification of the business. The enterprise can encode the goods, assets, tools or consumables according to the selected code rules, and then the corresponding files are searched by the back-office system on the basis of the code.
In the actual RFID project, engineers usually also use the business identification code for inclusion in the EP/UII storage area as the EPC. It needs to be noted, however, that the RFID storage area concept of the code carrier is not exactly the same as the Electronic Production Code in the GS1 EPC standard. If the project requires the use of GS1 EPC, data should be generated in accordance with the corresponding coding system and the unique rules.
The fact that the EPC is the only global person depends on the coding system, numbering allocation and project management approach, and that the name of the field is the EPC does not imply natural uniqueness. The project requires code generation, writing, binding, patching and scraping rules to avoid duplication.
The EPC area is written on many labels, but whether to allow rewrite, lock and how many bits of data can be written is to be confirmed according to chip functionality and project permissions. Therefore, it cannot be said that EPC can never be modified in general terms.
What's a TID?
The system can read this information to identify the type of chip, the supporting tag or the rules for participation in the binding.
Most of the common chips are written by the chip manufacturing chain, which is usually used at project sites as data access. However, different chips may have different designs for the length, uniqueness, accessible mode and locking characteristics of the chip, and must have access to specific chip specifications when it involves a security or unique identity determination.
TID does not automatically equal the full trade identity. After a label is read to TID, the system still needs to know which commodity it bound, when it bound, whether it changed the label and whether it changed the label and what it is doing.
What's User Memory?
User Memory is an additional user storage area provided by some label chips that allows you to save a small amount of extended data as required by the project. The capacity, reading and writing times, access passwords and locking capabilities vary according to the chip model.
Projects can save batch clips, status tags or other agreed data here, but not all operations are necessary. The complexity of writing, synchronization and unusual processing is added by the large number of variable business fields written into the label.
If the system only needs to search for back-office files through the EPC, selecting a label without a large capacity of User Memory may also fully satisfy the need.
What's the difference between EPC and TID?
| Comparative item | EPC | TID |
|---|---|---|
| Main uses | Operation ID code for project design carried | Description of identity and manufacturing information related to the label chip |
| Data sources | Usually generated by coding systems or project equipment, written | Usually provided by the chip manufacturing chain. |
| Whether or not to normally write by the business system | Common items are written or managed | It is usually read on the project site, based on the chip specifications |
| Common use methods | Related commodity, asset, tool or material archive | Support chip identification, tag verification and binding judgement |
The EPC and TID can be used in combination, but they have different roles. The EPC is more in line with the business code, the TID is more in line with the label chip itself, and the system should be kept and interpreted separately.
Should the RFID project label all business data?
Usually unnecessary. More commonly, labels are designed to maintain stable, short identification codes and software backstages to maintain a variable business file.
For example, the example of ASSET-000001 is maintained in the label, which is used to describe how the label data are associated, not in GS1 EPC code format. Asset Transfer is only updated for the background position and responsible person and does not need to rewrite all fields in the label.
This approach is more conducive to rights control, bulk maintenance, historical tracking and system expansion. Only when offline reading or a particular industry process does a label need to carry additional data should User Memory be evaluated and the version, validation and synchronization rules be designed.
How does the EPC and TIDs be used for commodity traceability and forgery prevention?
The system determines whether there are anomalies based on binding, scanning location, time and operational flow.
The label chip properties, code confidentiality, binding rules, data signatures, channel records and abnormality detections may affect the overall effect. A mere declaration that “tid can be used to protect against forgery” ignores the risks of label copying, migration and misuse of business data.
This section only explains the basic relationship of the data area. Specific traceability or anti-counterfeiting programmes also need to be designed separately in conjunction with the value of the commodity, the mode of attack, the certification terminal and the operating process.
FAQs
Could EPC re-write?
Many common UHF labels support writing in the EPC area, but rewriting, locking and length of writing depends on the chip specification and project permission settings.
Can TID modify it?
The TIDs of most common chips are written in the manufacturing chain and are usually used as read-only information at project sites; different chip designs may differ and should be based on the chip data manual.
Does every RFID Tag have User Memory?
Not necessarily. The availability and capacity of User Memory vary according to the chip type, and some labels do not have additional user storage areas for the project.
Is RFID just using TID enough?
Often not enough. Counterfeiting also requires consideration of labelling binding, data rules, validation processes, abnormal detection and anti-movement labelling, with the specific ability to depend on the full programme.