The call termination on 2N® Analog Intercoms devices can be done as described bellow:
- The busy or continuous tone *) after the call end.
- The ringing tone *) after a predefined count of rings.
- The subscriber 'at the other end' pressed .
- The preset maximum call duration has elapsed.
- 30 seconds after the switch use has elapsed.
- A 2N® Analog Intercom button was pressed during the call.
- The keypad button was pressed during the call (can be disabled).
*) The communicator is able to detect a permanent tone, busy tone and ringing tone even if the tone has two frequency components as in the UK, the U.S.A. (the so-called BTT tone) and in Canada. This new function does not require setting of any parameter. One of the tone components must be of 440 Hz.
In case that the device would not detect the Busy tone (or continuous tone) correctly you have to verify the setting of parameters described bellow
941 Minimum continuous tone time, if the tone is longer, the intercom hangs up. (default value 20=2s, range 10-99)
942 Minimum busy tone or pause duration, this parameter control the busy tone detection. They are used for call termination. (default value 8=0,08s, range 0-255)
943 Maximum busy tone or pause duration, this parameter control the busy tone detection. They are used for call termination. (default value 8=0,08s, range 0-255)
944 Maximum tone-pause difference, this parameter control the busy tone detection. They are used for call termination. (default value 8=0,08s, range 0-255)
Explanation of Parameters 942, 943, 944
The parameter 942 has to set regarding to the shorter part of the busy tone. In case that the period of tone time is longer than pause time we must set the parameter for pause.
The busy tone in the pic. 1 in the figure above is considerably longer than the pause time. Therefore, set parameter 942 according to the pause, to 200 ms, e.g., and parameter 943 according to the tone, to 600 ms, for example. In this case, however, the default values can be maintained for both the parameters. Since the tone – pause difference is 500 − 250 = 250 ms, set parameter 944 to 300 ms, for example.