2N® Indoor Touch offer on the opposite site ports to connect bell button directly to the device. As you can see on the picture, there are IN1, IN1/OUT1, IN2, IN2/OUT2, DC12+ etc.
This new PCB is available for new IndoorTouches from the Spring 2016. The bell button will not work at for the older HW even with the new application Helios IP Mobile ver. 4.1
Logical One – With Logical One button it is possible to change the logic of the button. GPI1/2 are by default in logical 1.
logical 1 is 1 – Clicking at the button will be input change into logical 0, application is not ringing. After clicking is the logic of the input back logical 1 and the application will start ringing. The maximal ringing time is possible to setup in the settings in section Maximal ringing time, too.
For more information please follow this manual
As you can see on the pictures are calls saved in Call Log that use bell button.