ACR122U emulate JIS 9319-4 tag instead of ISO 14443-4 tag when keep phone on the reader

问题

I have a strange problem. When i emulate a tag with the ACR122U it normally emulate a ISO 14443-4 (NfcA) tag. This always works in the following sequence:

• Start emulating with tgInitAsTarget
• Phone on the reader
• Transaction succesfull
• Phone off the reader

But in this sequence below the emulated tag is recognized as a JIS 9319-4 tag

• Start emulating with tgInitAsTarget
• Put phone on the reader
• Transaction error
• Retransmit tgInitAsTarget
• Not a ISO 14443-4 tag anymore
• Phone off the reader

So if i keep my phone on the reader and start another tgInitAsTarget it doesn't recognize the tag correcly. Why is this?

Regards,

来源：https://stackoverflow.com/questions/25487986/acr122u-emulate-jis-9319-4-tag-instead-of-iso-14443-4-tag-when-keep-phone-on-the