# Microphone Listening Period at End of Session

When set to ON, the RTU built-in microphone is activated for 15 seconds, upon entry of DTMF 0, 3 or 9. After the 15 second listening period, the call is terminated without need to enter additional DTMF tones. When set to OFF, there will be no listening period and the call is terminated immediately.

Note: Some DTMF detection is effected with the remote microphone is ON. If you are experiencing problems try turning this option off and determine if the problem goes away.