Today we bring you important news regarding changes to the NXP UCode 7 (SL3S1204) and UCode 7m (SL3S1214) RFID chips.
The changes are to the automatically implemented pre-serialization functionality which will be replaced with a simpler and easy to use solution with a wider range of compatibility with RFID readers and printers.
To sum it up: the unique pre-programmed EPC of the tags is serialized with exactly the same content as it used to be in the past, but, if the user overwrites it with another value, then they cannot use the special function which restores it automatically by writing zeroes (“00000000”) at the end of the EPC. Due to this change, NXP introduced a different TID header to be able to distinguish old and new versions.
The old automatic pre-serialization
In case the EPC length is set to be 96-bit, the EPC is by default self pre-serialized following a 96-bit EPC serialization scheme according to the Multi Vendor Chip-based serialization guideline, meaning the lower 38-bit will always contain 3 bits for the manufacturer code (111 for NXP) and 35 bit serial number taken from the lower 35 bits of the TID serial number.
As long as the initial content of the lower 38-bit of the EPC is not changed, the EPC will appear serialized. As soon as any of those 38 bits are written, the EPC will show the written content. Once the pre-serialization of the EPC is overwritten and the EPC is not locked, the self pre-serialization can be re-activated by one of the following ways:
– Setting the 38-bit Serial number of the EPC to “0”
– Erase sixth and fifth word of the EPC to “00 00h” and keep the content of the lower 6 bits of the fourth word of the EPC at its serialized content
The self pre-serialization only applies to an EPC length of 96 bits, which is the initial EPC length settings of UCODE7.
The new pre-serialization
Devices will be delivered with a pre-programmed 96-bit EPC memory content which consist of
– 8-bit Class Identifier,
– 12-bit Mask Designer ID,
– 12-bit Model Number,
– 16-bit “0”
– 48-bit Serial Number.
The serial number is derived from factory programmed TID and therefore identical with the serial number of the TID.
How this might affect you
In the majority of cases this change should not impact you, unless the automatic pre-serialization procedure was explicitly used for encoding. It is also important to note that the UCode 7 and 7m chip will get a new TID header to enable differentiation in the field.
|UCode 7||UCode 7m|
|Old TID header||E2806810||E2806811|
|New TID header||E2806890||E2806891|
RFIDdirect still has a small supply of labels containing the old UCode 7 chip but any new labels dispatched from December onwards will contain the new chip.
Please contact us if you are unsure whether this will affect your project/application and we will be happy to support you.
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