Reading ISO 15693 tags on iOS13 - ios13

Question

I'm implementing new feature in my app that should allow users to scan NFC tags. I've got some tags for testing that NFCTagReaderSession finds as ISO 15693 tags. I'm able to find and connect to a it, however, when I try to read data stored on a tag using
-readMultipleBlocksWithRequestFlags:blockRange:completionHandler:
mehod, it reports no error and always returns empty (zero-filled) data. I tried to change request flags etc., but no matter what I do, it always returns zero-ed data. Tag itself is OK as when I scan it with external BT reader it finds its value OK. I'm doing following after connecting a tag:
- (void)readISO15693Tag:(id)tag {
[tag getSystemInfoWithRequestFlag:(RequestFlagHighDataRate) completionHandler:^(NSInteger dsfid, NSInteger afi, NSInteger blockSize, NSInteger blockCount, NSInteger icReference, NSError * _Nullable error) {
if(!error) {
/// This prints "DSFId: 0, AFI: 0, Block size: 4, Block count: 28, IC Reference: 1"
NSLog(#"DSFId: %ld, AFI: %ld, Block size: %ld, Block count: %ld, IC Reference: %ld", (long)dsfid, afi,blockSize, blockCount, icReference);
NSRange blockRange = NSMakeRange(0, blockCount);
[tag readMultipleBlocksWithRequestFlags:RequestFlagHighDataRate blockRange:blockRange completionHandler:^(NSArray * _Nonnull dataBlocks, NSError * _Nullable error) {
NSMutableData *response = [NSMutableData data];
for(NSData *blockData in dataBlocks) {
[response appendData:blockData];
}
if(response.length > 0) {
NSData *rawData = [response subdataWithRange:NSMakeRange(1, (response.length - 1))];
/// Prints Received data: {length = 111, bytes = 0x00000000 00000000 00000000 00000000 ... 00000000 00000000 }
NSLog(#"Received data: %#", rawData);
}
}];
}
}];
}
}];
}
}];
}
I've got no clue what can be wrong with it. Did anybody have similar issue?
Thanks
Matt

Answer 1

Ok, I've figured it out. I was simply confused that external RFID scanner returns some data while I can see empty data returned by - readMultipleBlocksWithRequestFlags:... method. It turned out that the RFID scanner simply returns tag's UID, it actually does not read tag contents. The tag I'm trying to read IS actually empty.
So this question can be safely ignored.
Best
Matt