Telephone Line Control Units...

This control unit was designed for eliminate the unconformity between internal telephone exchange and telephone exchange of telecommunication provider.

Sometimes the lines can stay disconnected, and have a ' Busy tone' on the lines. This is because of the unconformity. ' Disconnect tone detector ' is used to eliminate this situation. The lines are checked after the lines hanged up, and disconnected to prevent busy tone.

The unit can learn up to 16 different disconnect tones.