October 2004, Issue 171

Telephone Message Watchdog
An Intelligent Call-Forwarding System

USAGE and PRESETTING

You have to preset your pager and home numbers before use. To do so, first connect a regular telephone to the presetting port J1. After the device is powered on, push in the mode switch (S1) to enter Presetting mode. The device now waits for you to enter the pager number and phone number using the telephone’s keypad (see Table 2). Punching the 0 key followed by the * key enters Pager Number Setting mode. The 1 key followed by the * key enters Home Phone Number Setting mode. Then the pager or home phone number can be entered and terminated by pressing the # key.

The LCD will show the number you entered. Each number entered is instantly saved even if the mode switch is changed back to Normal mode before the # key is pressed to stop either of the setting modes.

Connect J2 to the telephone port and J3 to an answering machine. After the system is preset, switch S1 back to normal. Now the system is ready to use. To test it, you can use a second line or cellular phone to dial this line number. After the answering machine triggers and waits for a message, you can punch in a callback number. The LCD should correctly display the number you entered. After you hang up the phone, the system will enter Information Forwarding mode and dial out the pager number as well as the number you entered. To monitor Information Forwarding mode, you can add an audio monitoring circuit to the system (see Figure 5). You can then hear the generated touch-tone.