Consider the Alien Higgs 4 IC. This post, https://urn.su/en/RFID/rfid_basics.php, describes the memory map for the EPC and the TID. And the GS1 Data Standard, https://www.gs1.org/standards/epcrfid-e … d-tds/1-13, shows a 16-bit CRC field for the EPC. But I don’t see any CRC field for the TID.
If there is no CRC, how can one be sure that the 64-bit Tag ID in the Higgs 4 (as an example) is the correct bits when they are read?
There are many CRC checks during the communication.
The commands and responses between Arduino(variant) and Nano have CRC added/checked by the driver.
For communication between de Nano and a TAG to be correct there are MANY checks as part of the standardized protocol, including CRC. Many defined in https://www.gs1.org/sites/default/files … 131101.pdf) The CRC for the EPC is just another one.
On user level we should not have worry given all this whether the data is correct or not. We get the right data or NO data and/or an error message.
Thank you! Fantastic reference. I was definitely not looking at the right spec (looking at memory spec vs. the air interface spec). It seems I was focused on the “StoredCRC”, whereas all those checks are specified in the “PacketCRC” sections.
The following sections of that spec were helpful for this:
Section 6.3.1.5 gave a nice overview
Section 6.3.2.1.2.1 described how StoredCRC and PacketCRC are managed/used
Table 6.17 and Table 6.28 were good examples of the structure
Thanks again!