Outbound telemetry device

A method for operating an outbound telemetry device situated at a first location, and which is capable of gathering data with respect to conditions at said first location, said outbound telemetry device being further capable of sending said data over a phone line to a central monitoring station situated at a second location which is remote from said first location, said method comprising the steps of:

• assuming a quiescent state wherein said device monitors said phone line for alerting signals;
• detecting the presence on said phone line of an alerting signal assigned to said device;
• seizing said phone line in response to detection of said alerting signal, said device thus entering an active state;
• transmitting telemetry data on said phone line, said data containing information with respect to said conditions;
• continuously monitoring by said device, when said device is in the active state, for the presence of AC waveform transitions in the telemetry data transmitted by said telemetry device to determine if said telemetry data is being transmitted by said device;
• maintaining said device in the active state as long as telemetry data is being transmitted on said phone line as determined by said continuously monitoring step, and
• disengaging said device from said phone line when said telemetry data is determined not to be present as determined by said continuously monitoring step.

A method for operating an outbound telemetry device situated at a first location, and including a processor capable of gathering data with respect to conditions at said first location, said outbound telemetry device being further capable of sending said data over a phone line to a central monitoring station situated at a second location which is remote from said first location, said method comprising the steps of:

• detecting the presence of a first signal on said phone line;
• taking said phone line to an "off-hook" condition when said first signal is detected to engage said device to said phone line;
• providing power to said processor from said phone line in response to detection of said first signal;
• said processor transmitting said data over said phone line to said central monitoring point as telemetry data;
• sensing by said device for the presence of AC waveform transitions in the telemetry data transmitted from said processor to determine the cessation of transmission of telemetry data from said processor;
• maintaining said device in said "off-hook" condition to engage said phone line for so long as said AC waveform transitions are sensed in said sensing step;
• providing a delay equal to a predetermined relatively short period of time after cessation of transmission of telemetry data is determined in said continuously sensing step, and
• returning said phone line to an "on-hook" condition after said delay has occurred to disengage said device from said phone line.