Using the Dialer
Using the Dialer in Hotline Mode
For most configurations, using the dialer in hotline mode is as simple as picking going off-hook. When the dialer detects a trigger condition such as a time after going off-hook, or detection of dial tone, the dialer will dial out the hotline number. The user will hear tones as the dialer dials. Then the call will proceed with normal call progress tones. That's all there is to it!
In other cases, the user must consciously choose to have the dialer dial the hotline number. For example, the trigger could be a 3-second pause after coming off-hook, or the trigger could be holding down the first digit of the hotline number for .6 seconds or more. In the first case, the user must remember not to dial anything until the programmed pause expires. In the second case, the user must remember to hold down the first digit of the hotline number for .6 seconds or more. In both cases, once the trigger occurs, the dialer will dial the hotline number (or, more precisely in the second case, the rest of the hotline number). If the user doesn't want to trigger the hotline number, or if they don't know about the hotline number, they can dial normally, and the dialer will let them do so without interfering unless you've programmed it otherwise.
Another way the dialer can be used in hotline mode is for remote sensing applications. The trigger in this case could be either going off-hook and pausing for a short length of time, or powering up the dialer. In either case, the dialer relays an event detected by a sensor. The output of the sensor must be arranged so that if a relevant event occurs, either the phone line connected to the dialer is taken off-hook, or the dialer is powered up. If the dialer is set to trigger on power up, and the dialer is powered up, the dialer will go off-hook on its own. In this type of application, the receiving equipment identifies the calling site either by using ANI to detect the phone number of the dialer's line, or by decoding an ID string that the dialer sends after the receiving equipment answers.
Using the Dialer in Toll Restrictor Mode
When a user places a call that may be blocked (restricted), the dialer listens to the digits the user dials and stores them. While the dialer stores those dialed digits, they sound very soft because the dialer prevents them from being heard by the local telephone office. When the user has finished dialing, the dialer decides whether the call should be restricted or not. If it is restricted, the dialer quickly sends a number to the central office, so that the user can't redial the restricted number. If the number is allowed, the dialer redials it. When the dialer finishes dialing, it waits passively on the phone line waiting for another call.
