Interrupting background music with a tone on the Netbell-NTG Tone Generator

The Netbell-NTG can play custom audio files as well as control bells and buzzers, but you can also run background music through it and interrupt the music when you need to play a message. This is done by connecting a music source such as an mp3 player or a radio to the Normally Closed connections on the relays as well as to the amplifier. Below I will show you how to do this.


From your music source you will need to wire the positive leads to the common (C) connection to the relays. The ground leads will have to be connected to both the Line Out connections and the amplifier’s ground connections. From the Netbell-NTG to the amplifier, you will need to connect the normally closed connections from the relays to both the Line Out left and right and to the amplifier’s left and right connections. Reference the diagram below to ensure it is wired correctly.

Setting Relays

Next, you will need to log in to your Netbell-NTG unit and navigate to the Relays page under the Services drop down menu. Set the Pulse Width on both relays 1 and 2 to 0 and set the Pulse Width Multiplier to None. If you want to use more than two tones, navigate to the Settings page under the Settings drop down menu and select the option “Extend Relay Range”. This will open up an addition four virtual relays. If you need to set parameters for these new relays, you will need to manually enter the URL – Set the end of the URL to read “/p/relays8.htm” as shown below. Otherwise, continue to the next step.

After setting up relays 1 and 2 and activating the additional virtual relays if needed, navigate to the Tasks page. Create tasks using relays 3 through 8 to play a desired tone. Using the Bell Scheduler app, schedule your messages using relays 1 and 2 to turn off the background music, and then also check the relay corresponding to the message you wish to play. Set the duration and Pulse Width Multiplier on the app to match the duration of your message.

Setting a pushbutton

If you have a microphone connected to your PA system you can use a pushbutton to stop the music while you make an announcement. Wire a button to a Digital Input 1 and switch that input to Pull-Up mode. Navigate to Services > Inputs and click the Pencil icon on Digital Input 1 you wired your button to. From here check the Use box, set the Type to State.

Now you will need to Set four tasks. Navigate to the Tasks page and set one task: If State 1S=0 Then Relay 01 On. The second task should be: If State 1S=1 Then Relay 01 Off. The third task should be: If Relay 01+ Then Relay 02 On. And the Final task is: If Relay 01- Then Relay 02 Off.

When you push your button Both relays will turn on, stopping the background music until you release the button. Please note that a microphone will have to be wired seperately from the Netbell-NTG. Whether you are are using this in an office, a waiting room, a grocery store, or any other location where you may have music playing, you can use the Netbell-NTG to interrupt the music with your message so it can be heard loud and clear.