...That almost sounds like that the VTH1550CH might not be 100% compatible with the new? VTO3211? Mhmhmhmhm... or is it just a matter of the firmware?...
in fact in you vidéo you have 3 VTH1550CH with old firmware, this firmware doesnt works with VTO3211, you need the last firmware for VTH1550CH or use VTH5211CH who use the good firmware.
...so you can issue/deissue cards at the intercom or some Smart PSS !?...
you can add with the interface or remote with Smart PSS
Thanks,
INT