Techniques for processing an incoming message from premises equipment at a monitoring location. In one embodiment, an event message, including digits with varying amplitudes, is generated at a premises (such as a home, office, factory, etc.) in response to an event at the premises. A communication channel is established between the premises equipment and the monitoring location and the event message is sent from the premises equipment to the monitoring location. The entire event message is evaluated based on the number of digits received compared to expected receiving parameters defined in a communication protocol. A number of possible interpretations of the event message is determined. One or more possible interpretations of the event message are eliminated based on the number of digits in each of the possible interpretations to create a subset of possible interpretations. Receipt of the event message is determined by selecting one possible interpretation from the subset of possible interpretations based upon the number of digits received by the monitoring location within a predetermined protocol time.