Hello sir,
Thank you for your interest in our products.
Unfortunately the support I can provide for such implementation is limited since I am not able to reprodue this scenario.
As stated in the Datasheet the structure is compliant with ISO 7816-4 but, the commands aren't.
If the OMNIKEY can only send ISO 7816-4 compliant commands is possible that the communication cannot be done this way.
It may be required to evaluate the setup using wither other reader or, a host between the reader and the SAM.
Still, I have to mention that SAM AV2 isn't recommended anymore for new designs, please explore the possibility of using SAM AV3.
Best Regards,
Fabian