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CShac
Associate III
Feb 20, 2019 10:03 AM UTC
Solved

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

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.
Bart Herse
Bart HerseBest answer
Visitor II
Apr 3, 2019 7:30 AM UTC

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

Bart Herse
Bart HerseBest answer
Visitor II
Apr 3, 2019 7:30 AM UTC

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