Hi, I am trying to get a Feitian R502 dual interface reader working with NTAG 213 to read and write data.
Have anyone gotten NTAG 21x versions to work on such readers besides the usual ACR122 ?
Sure. The R502 and R502-CL are PC/SC-compliant and read NTAG 21x just fine:
(It says Mifare Ultralight but it’s a NTAG 216)
I am following this thread (Reading NTAG216 User Data pages w/ ACR122U and Python) and trying to send APDU
FF 00 00 00 05 D4 42 3A 04 06
and I am getting 0x6E00 over R502.
As far as I know, FF 00 00 00 is the direct transmit command, and I think it’s ACR122U-specific.
Yeah when it comes to pseudo-APDUs,.each reader model has its own commands… acs calls this direct mode while omikey calls theirs transparent mode… and the commands are different.
Got an official response from Feitian that the R502 contactless does not support NTAG. Customized firmware are needed but that is as good as no support for NTAGs.
If the Feitian has a passthrough command - which I’m sure it must have - you can roll your own. I think they meant support within the firmware.
The question is, what’s the passthrough command… 
I think one who could help you here is Fraggersparks