Can't write or read SRI512 cards

[APell.2]

Hello, sorry for the inconvenience but I really can't understand why I can't write/read new cards (the ones he has work) from my customer reader. What am I doing wrong?

I enclose the photos, his card (working and writable / readable) and the one I created for him.

Thanks again,

Andrew

[APell.2]

Could it be that the reader checks through an algorithm if the UID corresponds to block 5?

[Tesla DeLorean]

Not exactly a wealth of detail to work from here..

Perhaps talk the vendor of the equipment, it might be less trivial than simply duping card content?

Could be a checksum, hash, or CRC of some type.

Perhaps review more than one exemplar?

[APell.2]

Thank you for your answer @Community member​.

I don't think the vendor is very inclined to provide me with such specific assistance, especially when he sells the cards for €3 each, and I own a hotel: I'm always more certain that block 5 is that it prevents me from using the cards found elsewhere.

I have verified that all the blank cards he has supplied me have block 5 that is always different, the rest is empty.

Now comes the fun part: how will I ever be able to understand the mechanism?

[APell.2]

I picked block 5 from 60 different cards today!

[Berenice BENVEGUDA · Accepted solution]

Hello,

first of all thanks for your interest in ST25 tag products.

on SRI512, block 5 corresponds to a count down binary counter.

You can only write a value which is smaller that the current one in this block.

Best Regards,

BB