Joined: 29 April 2008
Location: BE
Posts: 2

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We are using the MLX90121 ic for reading HF tags but some tags simply doesn't respond while others work whithout problems. According to me, it can't be that they use another protocol because the tags are send to us as a ribbon of tags stitched to each other. First we thaught that there might be anticollision problems but we've cutted them apart from each other and still some tags doesn't respond. Is it possible that we made a mistake with the CRC? You'll find a piece of our C-code on http://users.telenet.be/kennyvdn/melexis/code.txt Kind regards Kenny

Joined: 1 February 2006
Location: CH
Posts: 102

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Dear Kenny,

The first thing to confirm is if the TAG replies to your command. This can be easily check by sampling the field of the RFID reader (with the TAG close to the reader's antenna) or with a small loop put on the TAG itself.

By observing or not the back modulation of the TAG, you know if the problem is in the command sent by the reader or in the answer of the TAG. Then, further investigations can be made accordingly.


Best Regards
Denis

Joined: 29 April 2008
Location: BE
Posts: 2

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Problem solved, it had something to do with the mask value in the inventory request

thanks anyway

Kenny

Joined: 24 November 2007
Location: IN
Posts: 3

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hi kenny

i am also getting problem in tag reading,
bt i think i have problem in antenna.
plz contact me at rajan.manhas@gmail.com

Regards,
Rajan