In many cases we like to adjust the gain of the microphone and speaker of the SC220. Read this FAQ to get the instruction how.
The telephone has a set of configuration parameters which are set up by the installer by use of the keyboard.
In order for programming the parameters, do the following:
1 - Hang on the headset and handset.
2 - Press the R button for 2 seconds.
Red indicator starts to flash.
3 - At the same time press the # key and the parameter number.
Green indicator the starts to flash.
4 - Enter the parameter value.
Red indicator starts flashing and You can go to step 3 again