Thank you so much for your response.
Is this the receiver phone, witch is connected to that pharmacy system or a DTMF decoder? For sure I will test with It ASAP. I hope you tell me if there some settings you done on this phone.My phone is a Samsung Galaxy 7 Edge.
Did you try to connect this one to that system and get it to work? Can any DTMF decoder detect key pressed with this phone?I then called my desk phone. When I press a number on my mobile, I hear a beep in my mobile, but nothing from my desk phone receiver.