Outbound telemetry device

• US 5,204,896 A
• Filed: 05/05/1992
• Issued: 04/20/1993
• Est. Priority Date: 08/10/1990
• Status: Expired due to Fees

• Current Assignee: Firstpoint Energy Corporation NA
• Original Assignee: Telegenics, Inc.
• Inventors: Oliver, Stewart W.
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): MATAR, AHMAD
• Application Number:
  US07/880,299
• Time in Patent Office: 350 Days
• Field of Search: 379/106, 379/107, 379/98, 379/104, 379/105, 379/102, 340/870.02, 340/870.03
• US Class Current: 379/106.04
• CPC Class Codes: H04M 11/002 with telemetering systems telemetering in general G08C

Abstract

A outbound telemetry device type of meter interface unit (MIU) is provided which enables the automated collection of utility consumption information from a telephone subscriber'"'"'s site via a conventional subscriber phone line between a central office and the subscriber'"'"'s site. The unit includes a processor which is capable of collecting consumption information at the subscriber'"'"'s site. The processor draws electrical power from the phone line in an electrically isolated fashion. When the unit detects the presence of an alerting signal intended for that particular unit, the unit seizes the phone line. The processor then transmits telemetry data with respect to the information back over the phone line. The unit continues the seizure of the phone line for so long as the telemetry data transmission from the processor continues. The unit includes a data detection circuit which detects when the telemetry data transmission ceases. A disengaging circuit within the meter interface unit disengages the unit from the phone line when the detection circuit detects that the telemetry data transmission has ceased. In this manner the unit readily accommodates telemetry data transmissions of virtually any size including variable duration without seizing the subscriber'"'"'s phone line for undue periods of time.

Claims

1. A remote outbound telemetry device situated at a first location for monitoring conditions at said first location and for reporting information regarding said conditions over a phone line back to a central station situated at second location which is remote from said first location, said telemetry device comprising:

alerting signal detecting means, responsive to an alerting signal on said phone line, for detecting the presence of said alerting signal and providing a detect signal when said alerting signal is detected;

accessing means, coupled to said alerting signal detecting means, for engaging said phone line in response to said detect signal and for disengaging said phone line in response to a disengage signal;

telemetry generating means, coupled to said alerting signal detecting means, for generating telemetry data in response to said detect signal, said data containing information with respect to said conditions;

transmitting means, coupled to said telemetry generating means, for transmitting said telemetry data on said phone line, and

AC detector means, coupled to said telemetry generating means and said accessing means, for detecting the presence of AC waveform transitions in the telemetry data generated by said telemetry generating means, said AC detector means providing said disengage signal when the presence of said AC waveform transitions is no longer detected, such that said outbound telemetry device is disengaged from said phone line a predetermined amount of time after the cessation of said telemetry data is recognized by said AC detector means detecting that said AC waveform transitions are no longer present.

2. The outbound telemetry device of claim 1 further comprising modulating means for modulating said telemetry data onto a signal on said phone line.

3. The outbound telemetry device of claim 1 further comprising electrical isolation means, coupled between said telemetry generating means and said phone line, for providing power from said phone line to said telemetry generating means and for providing electrical isolation between said telemetry generating means and said phone line.

6. The outbound telemetry device of claim 1 further comprising biasing means, coupled between said phone line and said telemetry generating means, for providing DC voltage bias and current from said phone line to said telemetry generating means, the maximum bias current provided by said biasing means being selected such that, when the user activates another communications device on said telephone line, said telemetry generating means becomes current-starved so that any telemetry data then being transmitted by said telemetry generating means ceases, thus causing said AC detector means to no longer detect said AC waveform transitions and in response thereto provide said disengage signal to cause said telemetry device to become disengaged from said phone line.

4. 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.

5. 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.