Terminal device management system and a method for detecting a failed terminal device using the system

• US 5,802,271 A
• Filed: 10/15/1993
• Issued: 09/01/1998
• Est. Priority Date: 10/20/1992
• Status: Expired due to Fees

• Current Assignee: Mita Industrial Co., Ltd. (Kyocera Corporation)
• Original Assignee: Mita Industrial Co., Ltd. (Kyocera Corporation)
• Inventors: Inenaka, Hiroyuki, Hashimoto, Yasuhiro, Yamashita, Yuji, Sako, Masahiro
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): WRIGHT, NORMAN M
• Application Number:
  US08/137,590
• Time in Patent Office: 1,782 Days
• Field of Search: 371/15.1, 371/16.4, 371/16.5, 371/20.1, 395/575, 395/185.01, 395/185.04, 395/185.08, 395/183.19, 395/183.2, 364/231.5, 364/240.4, 364/942.04, 364/267.1, 364/270.2, 379/164, 379/9, 379/133
• US Class Current: 714/44
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors
• CPC Class Codes: H04M 11/002 with telemetering systems telemetering in general G08C

Abstract

A terminal device management system includes a plurality of terminal devices and a remote management apparatus for remotely managing the plurality of terminal devices. The remote management apparatus includes a data receiving section, a management table storing section for storing a management table including identifiers for the terminal devices which are set to transmit data in a transmission time interval for identifying whether data has been Bent from the terminal devices or not, a timer section for measuring a time period during which a line is not connected in the transmission time interval, and a control section for detecting whether or not the time period measured by the timer section reaches a predetermined time period, and for, when it is detected that the predetermined time period is reached, detecting a terminal device the identifier of which in the management table stored in the management table storing section indicates data has not been received therefrom, as a failed terminal device.

Claims

1. A terminal device management system including a plurality of terminal devices and a remote management apparatus for remotely managing said plurality of terminal devices, said remote management apparatus being connected to said plurality of terminal devices via a line,

each of said plurality of terminal devices comprising:

data storing means for storing data to be transmitted;

data transmitting means for transmitting said data stored in said data storing means to said remote management apparatus;

transmission time interval storing means for storing a transmission time interval; and

terminal device control means for requesting a line connection to said remote management apparatus in said transmission time interval stored in said transmission time interval storing means, and for, when said line connection is not attained, repeatedly requesting said line connection every predetermined first time period in said transmission time interval, said predetermined first time period being shorter than said transmission time interval,

said remote management apparatus comprising;

data receiving means for receiving data transmitted from said terminal devices;

management table storing means for storing a management table including at least identification names of terminal devices which are previously set to transmit data in said transmission time interval and corresponding identifiers for said terminal devices having said identification names for identifying whether data has been sent from said terminal devices or not;

timer means for measuring a time period during which said line is not connected in said transmission time interval; and

remote management apparatus control means for detecting whether or not the time period measured by said timer means reaches a predetermined second time period set to be longer than said first time period, and for, when it is detected that said predetermined second time period is reached by said measured time period, identifying a respective terminal device as a failed terminal device in the event said corresponding identifier in said management table stored in said management table storing means indicates data has not been received from said respective terminal device.

2. A terminal device management system according to claim 1, wherein said first predetermined time period and said second predetermined time period for each of said plurality of terminal devices are different from those for the other ones.

3. A method for detecting a failed terminal device in a terminal device management system including a plurality of terminal devices and a remote management apparatus for remotely managing said plurality of terminal devices, said remote management apparatus being connected to said plurality of terminal devices via a line,

said method comprising the steps of:

requesting a line connection from each of said terminal devices to said remote management apparatus in a transmission time interval;

repeatedly requesting said line connection every predetermined first time period In said transmission time interval, when said line connection is not attained;

storing a management table in said remote management apparatus, said management table including at least identification names of terminal devices which are previously set to transmit data in said transmission time interval and identifiers for said terminal devices having said identification names for identifying whether data has been sent from said terminal devices or not;

measuring a time period during which said line is not connected in said transmission time interval; and

detecting whether or not said measured time period reaches a second time period which is previously set to be longer than said first time period, and, when it is detected that said second time period is reached, detecting a terminal device said identifier of which in said management table indicates data has not been received therefrom, as a failed terminal device.

4. A method according to claim 3, wherein said first time period and said second time period for each of said plurality of terminal devices are different from those for the other ones.