These guys

http://www.2n.cz/en/products/intercom-systems/door-and-security-intercoms/helios-ip-vario/

Tell me their product is compatible with the Cisco UC320 and SPA525G2 phones it just functions as a voice endpoint. Cisco has also confirmed this.

My question is has anyone used one of these before? I'm told I should be able to have a button to unlock a certian doorstrike instead of having to enter a code. Does anyone know how this might be accomplished?