Hello Vishranti Patil:
For communicating between two PN7120 I guess you are referring to a Peer-to-Peer use case.
Do you have in mind some MCU Host or want to try this with a particular platform (e.g. Raspberry with Linux)?
The OM5577 kit page provides some useful application notes and examples under the "Downloads" tab:
PN7120 NFC Controller SBC Kit|NXP
For example the NullOS example project shows Peer-to-Peer, Card Emulation and Read/Write modes, supporting MIFARE tags.
There are as well some useful guides in this community:
Integrating NFC Controller library with KSDK
NFC PN7120 on the i.MX6Q
Boundary Devices - Android Lollipop NFC demo
About OTP service, please specify what exactly you mean with this.
Let us know if any questions.
Best Regards!,
Jorge Gonzalez
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