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Visitor II
February 20, 2019
Solved

Can anyone explain the bytes read back from the TID memory?

  • February 20, 2019
  • 1 reply
  • 811 views

I can see in the example firmware that the TID memory is read in multiple stages, with the first 8 bytes read first.

In my application I need only these first 8 bytes, so following a very similar process I can read these bytes. I am working with a CRC on reception. So I am expecting to receive 12 bytes comprising of the first 8 bytes of TID memory (which I do receive) + 2 bytes of indicating the tag Handle, which I also receive and finally two bytes of CRC, however when running a Genibus check the CRC fails.

Am I incorrect in what I am expecting from the read TID memory command? Would the CRC only be returned after a complete read of the TID memory?

The actual hex codes are shown below.

On completion I receive:

0xE2 0x00 0x38 0x11 0x60 0x00 0x60 0x15 0x31 0x1f 0xF0 0x3A

which when checking with https://crccalc.com/ would return 0xc3 0x50 using Genibus.

    This topic has been closed for replies.
    Best answer by Bart Herse

    Hello Chris,

    please check the Gen2 protocol documentation for the READ command

    https://www.gs1.org/sites/default/files/docs/epc/uhfc1g2_2_0_0_standard_20131101.pdf

    Cheers,

    B

    1 reply

    Visitor II
    April 3, 2019

    Hello Chris,

    please check the Gen2 protocol documentation for the READ command

    https://www.gs1.org/sites/default/files/docs/epc/uhfc1g2_2_0_0_standard_20131101.pdf

    Cheers,

    B