REMOTE MONITORING SYSTEM

• US 20100127880A1
• Filed: 11/21/2008
• Published: 05/27/2010
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: Digi International Inc.
• Original Assignee: Schechter Tech LLC (Digi International Inc.)
• Inventors: Felichko, Kevin, Schechter, Harry J.
• Granted Patent: US 7,952,485 B2
• Time in Patent Office: Days
• US Class Current: 340/584
• CPC Class Codes: G01K 1/024 for remote indication

Abstract

A temperature monitoring service in which remote monitoring units are distributed to customers who then set up monitoring as desired at their facilities. The devices may be registered through a web site using the Internet. Monitoring information may be communicated using a publicly available, wireless network, such as a cellular telephone network. The service may be provided with a system, including a server, architected to allow each remote monitoring unit to be simple and low cost. Similarly, the system may be architected to allow monitoring and control information to be communicated reliably, but at low cost. The server, however, can deliver high levels of monitoring functionality. The server may support using a variety of analytical methods to process the monitoring information, including analyzing the rate of temperature change at a monitored facility.

Claims

1. A method of remote monitoring for a plurality of customers, each having at least one remote unit comprising a sensor, a transceiver and indicia of an identifier, the method comprising:

receiving through a web site for each of a plurality of customers a registration of a remote unit, each registration of a remote unit comprising receiving;

the identifier of the remote unit;

one or more sensor output limits of the sensor of the remote unit; and

an indication of one or more alert actions;

in response to receiving a registration for each remote unit, establishing one or more scheduled reporting times for the remote unit;

receiving reports from the remote units, each report sent using the transceiver of the respective remote unit and each report comprising an indication of the output of the sensor of the remote unit; and

when the indication in a report received from a remote unit indicates that the output of the sensor of the remote unit is outside the sensor output limits of the remote unit, sending an alert in accordance with at least one of the one or more indicated alert actions for the remote unit.

2. The method of remote monitoring of claim 1, further comprising:

when no report is received from the remote unit at a scheduled reporting time for the remote unit, sending an alert in accordance with at least one of the one or more indicated alert actions for the remote unit.

3. The method of remote monitoring of claim 2, wherein receiving reports from the remote units comprise receiving reports over a GSM network.

4. The method of remote monitoring of claim 2, wherein receiving reports from the remote units comprise receiving reports over a mobile telephone network.

5. The method of remote monitoring of claim 1, wherein:

the indication of one or more alert actions comprises indicating a reporting format from a set of report formats, the set of report formats comprising e-mail, SMS, phone call and instant message; and

sending the alert comprises sending an alert message in the indicated reporting format.

6. The method of remote monitoring of claim 1, further comprising, in response to receiving a report from a remote unit, sending an acknowledgment to the remote unit, the acknowledgement comprising an indication of a next scheduled reporting time.

7. The method of remote monitoring of claim 6, further comprising:

determining the next scheduled reporting time, the next scheduled reporting time being a first time when the remote unit is in an alarmed state and a second time when the remote unit is not in an alarmed state, the second time being later than the first time.

8. The method of remote monitoring of claim 7, further comprising:

placing the remote unit in the alarmed state when a report from the remote unit indicates that the temperature and/or rate of change of the temperature is outside a specified range of temperature or rate of change of temperature, respectively, as indicated by the one or more received sensor output limits; and

removing the remote unit from the alarmed state when a report from the remote unit indicates that the temperature and rate of change of the temperature are inside the specified range of temperature or rate of change of temperature, respectively.

9. The method of remote monitoring of claim 6, further comprising:

establishing a scheduled reporting time for a remote unit, the establishing comprising;

receiving through the web site a reporting interval for the remote unit; and

when the remote unit is not in an alarmed state, computing the scheduled reporting time as a current time plus the reporting interval; and

when the remote unit is in an alarmed state, computing the scheduled reporting time as the current time plus a fraction of the reporting interval.

10. The method of remote monitoring of claim 1, wherein each report is formatted as a UDP packet.

11. The method of remote monitoring of claim 10, wherein each UDP packet from a remote unit comprises:

the identifier for the remote unit;

at least one command identifier;

a payload associated with the command identified by the command identifier; and

a CRC code.

12. The method of remote monitoring of claim 10, further comprising, in response to receiving a UDP packet from a remote unit:

checking the CRC of the packet;

when the CRC validates, processing the packet; and

when the CRC does not validate, sending a negative acknowledgement.

13. The method of remote monitoring of claim 12, further comprising at each of the plurality of remote units:

transmitting a report;

when an acknowledgement is received in response to the report, setting a timer to identify a next reporting interval based on information in the acknowledgement; and

when a negative acknowledgement is received in response to the report or no response is received to the report, retransmitting the report.

14. A method of remotely monitoring a plurality of devices generating reports, the method comprising:

for each report received;

selecting an initial processing thread from a pool of inactive initial processing threads;

initially processing the report by the selected thread, the initial processing comprising;

checking that the report is a valid command report;

when the report is not a valid command report, sending a negative acknowledgement in response to the report; and

when the report is a valid command report;

sending an acknowledgement in response to the report;

placing the command in a queue; and

retrieving a command from the queue and processing the retrieved command, the command processing comprising;

identifying a command processor adapted to process the retrieved command and assigning the retrieved command to the identified command processor; and

in the command processor, processing the retrieved command.

15. The method of claim 14, wherein checking that the report is a valid command report comprises determining whether the report comprises a command identifier within a set, the set comprising:

a command identifier indicating that a device generating the report has powered up;

a command identifier indicating that the report contains a reading from a sensor associated with a device generating the report; and

a command identifier indicating that a device generating the report has changed power sources.

16. The method of claim 15, wherein checking that the report is a valid command report further comprises computing a checksum on a packet containing the report and verifying that the report comprises an identifier of a valid command type.

17. The method of claim 15, wherein sending the acknowledgement comprises sending to a device generating the report an indication of a time for the device to generate a report.

18. The method of claim 17, wherein:

the indication of the time for the device to generate a report comprises an interval until the next report; and

the method further comprises, on the device;

setting a timer for the interval;

placing the device in a low power state; and

upon expiration of the timer, removing the device from the low power state.

19. The method of claim 17, wherein the method further comprises:

monitoring whether the device generates a report at the indicated time; and

when the device does not generate a report at the indicated time, generating an alarm.

20. The method of claim 15, wherein the method further comprises, on the device, in response to sending a report:

when an acknowledgement is not received within an interval, retransmitting the report; and

when a negative acknowledgement is received within the interval, retransmitting the report.

21. The method of remotely monitoring of claim 14, further comprising receiving a plurality of reports over a GSM network.

22. A method of remote monitoring temperature at a plurality of locations, the method comprising:

receiving reports from a plurality of devices, each device located at a location of the plurality of locations;

for each report received for a device,

when the report indicates a temperature for the device outside of temperature limits, then sending a first alert message, the first alert message being directed based on information stored for the device; and

when the report indicates a rate of change of temperature for the device outside a temperature rate of change limit, then sending a second alert message, the second alert message being directed based on information stored for the device.

23. The method of remote monitoring temperature of claim 22, further comprising:

computing the temperature rate of change limit for the device, the computing comprising;

processing successive reports from the device, each successive report indicating a temperature at a time associated with the report; and

computing a mean and deviation of the indicated temperature for successive reports received during an interval preceding the computing.

24. The method of remote monitoring of claim 23, further comprising:

determining whether the received report indicates a rate of change of temperature for the device outside a temperature rate of change limit by comparing a temperature indicated in the report to the computed mean plus a predetermined multiple of the computed deviation.

25. The method of remote monitoring of claim 22, further comprising:

receiving a registration for the device from a user of the device, the registration comprising the temperature limits and rate of change limit for the device.

26. The method of remote monitoring of claim 22, wherein:

receiving reports comprises receiving reports at a server; and

when, for a received report, the report indicates a temperature for the device outside of temperature limits or a rate of change of temperature for the device outside a temperature rate of change limit, then computing on the server a new reporting interval for the device and communicating the new reporting interval to the device.

27. The method of remote monitoring of claim 26, wherein computing the new reporting interval comprises:

dividing a value stored on the server representing a current reporting interval for the device by a predetermined value to produce a quotient;

when the quotient is above a threshold, using the quotient as the new reporting interval; and

when the quotient is below the threshold, using the threshold as the new reporting interval.

28. The method of remote monitoring of claim 27, wherein receiving reports comprises receiving reports over a GSM network.

29. The method of remote monitoring of claim 22, wherein receiving reports comprises receiving reports formatted as UDP packets.

30. The method of remote monitoring of claim 29, wherein receiving reports comprises receiving UDP packets over a cellular network.

31. The method of remote monitoring of claim 22, wherein receiving reports comprises receiving TCP packets over a cellular network.