Distributed supervisory control and data acquisition system

• US 5,475,867 A
• Filed: 02/06/1992
• Issued: 12/12/1995
• Est. Priority Date: 02/06/1992
• Status: Expired due to Fees

• Current Assignee: Itron, Inc.
• Original Assignee: Itron, Inc.
• Inventors: Blum, William R.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): VO, NGUYEN THANH
• Application Number:
  US07/833,467
• Time in Patent Office: 1,405 Days
• Field of Search: 455/32.1, 455/53.1, 455/54.1, 455/54.2, 455/68, 455/33.1, 455/56.1, 455/49.1, 455/88, 340/825.47, 340/825.44, 340/825.52
• US Class Current: 455/507
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A SCADA communication and control system is used for controlling power distribution. The system includes a master controller, a master ratio and a plurality of remote terminal units (RTUs). A communication link between the master controller and the master radio has two channels. A first channel is for sending master controller messages to the master radio. The second channel is for the master radio to send the RTU response messages back to the master controller. A supplemental controller along with supplemental remote terminal units (SRTUs) also are included for expanding the range of the system. A switch is included in the second channel so as to selectively link either the supplemental controller or the master radio to the master controller for providing response messages. The supplemental controller monitors the first channel to identify messages having an SRTU address. When such a message is identified, the switch is set to select the supplemental controller. In addition, the master radio is disabled from transmitting over the 900 MHz radio channel. Thus for SRTU communications, the supplemental controller has access to the 900 MHz channel and the response link back to the master controller. The supplemental controller includes a main task for monitoring and testing master controller messages. The main task defines the switch state and enables/disables the master radio access to the 900 Mhz channel. A network task also is included which controls communications with the SRTUs, either directly or through a sub-controller.

Claims

1. A distributed radio communication and control system, comprising:

master control means for controlling communications with a plurality of remotely-located first stations and a plurality of remotely-located second stations, each of said first stations having a first station address and each of said second stations having a second station address, the master control means generating master control means messages, each said message having a destination address;

master radio means, adapted to receive said master control means messages, for transmitting a master control means message to one of said first stations when one of said first station addresses corresponds to said destination address and for sending a response message to said master control means from said one first station;

supplemental control means for monitoring said master control means messages and for determining whether one of said second station addresses corresponds to said destination address, said supplemental control means transmitting a supplemental control means message to one of said plurality of remotely-located second stations when said one of said second station addresses corresponds to said destination address, said supplemental control means sending a response message to said master control means based upon a response from said one of said plurality of remotely-located second stations to said supplemental control means message;

means for selectively coupling either one of a master radio means communication channel and a supplemental control means communication channel to said master control means across which a response message is sent;

wherein said supplemental control means controls the coupling means to select the supplemental control means communication channel when said destination address corresponds to a second station address; and

means for coupling said master radio means and said supplemental radio means to a given antenna.

2. A distributed radio communication and control system, comprising:

master control means for controlling communications with a plurality of remotely-located first stations and a plurality of remotely-located second stations, each of said first stations having a first station address and each of said second stations having a second station address, the master control means generating master control means messages, each said message having a destination address;

master radio means, adapted to receive said master control means messages, for transmitting a master control means message to one of said first stations when one of said first station addresses corresponds to said destination address and for sending a response message to said master control means from said one first station;

supplemental control means for monitoring said master control means messages and for determining whether one of said second station addresses corresponds to said destination address, said supplemental control means transmitting a supplemental control means message to one of said plurality of remotely-located second stations when said one of said second station addresses corresponds to said destination address, said supplemental control means sending a response message to said master control means based upon a response from said one of said plurality of remotely-located second stations to said supplemental control means message;

means for selectively coupling either one of a master radio means communication channel and a supplemental control means communication channel to said master control means across which a response message is sent;

wherein said supplemental control means controls the coupling means to select the supplemental control means communication channel when said destination address corresponds to a second station address; and

said master radio means is disabled from transmittings a master control means message to a first station when one of said second station addresses corresponds to said destination address.

3. The system of claim 2, in which said master radio means is enabled for transmitting a master control means message to a first station when one of said second station addresses does not correspond to said destination addresses.

4. The system of claim 3 in which said supplemental control means controls said disabling and enabling of said master radio means.

5. A distributed radio communication and control system, comprising:

master control means for controlling communications with a plurality of remotely-located first stations and a plurality of remotely-located second stations, each of said first stations having a first station address and each of said second stations having a second station address, the master control means generating master control means messages, each said message having a destination address;

master radio means, adapted to receive said master control means messages, for transmitting a master control means message to one of said first stations when one of said first station addresses corresponds to said destination addresses and for sending a response message to said master control means from said one first station;

supplemental control means for monitoring said master control means messages and for determining whether one of said second station addresses corresponds to said destination address, said supplemental control means transmitting a supplemental control means message to one of said plurality of remotely-located second stations when said one of said second station addresses corresponds to said destination address, said supplemental control means sending a response message to said master control means based upon a response from said one of said plurality of remotely-located second stations to said supplemental control means message;

means for selectively coupling either one of a master radio means communication channel and a supplemental control means communication channel to said master control means across which a response message is sent;

wherein said supplemental control means controls the coupling means to select the supplemental control means communication channel when said destination address corresponds to a second station address; and

said master radio means and said supplemental control means are located at a common site remote from said master control means.

6. A distributed radio communication and control system, comprising:

master control means for controlling communications with a plurality of remotely-located first stations and a plurality of remotely-located second stations, each of said first stations having a first station address and each of said second stations having a second station address, the master control means generating master control means messages, each said message having a destination address;

master radio means, adapted to receive said master control means messages, for transmitting a master control means message to one of said first stations when one of said first station addresses corresponds to said destination address and for sending a response message to said master control means from said one first station;

supplemental control means for monitoring said master control means messages and for determining whether one of said second station addresses corresponds to said destination address, said supplemental control means transmitting a supplemental control means message to one of said plurality of remotely-located second stations when said one of said second station addresses corresponds to said destination address, said supplemental control means sending a response message to said master control means based upon a response from said one of said plurality of remotely-located second stations to said supplemental control means message;

means for selectively coupling either one of a master radio means communication channel and a supplemental control means communication channel to said master control means across which a response message is sent;

wherein said supplemental control means controls the coupling means to select the supplemental control means communication channel when said destination address corresponds to a second station address;

wherein said supplemental control means comprises means for executing a main task for monitoring said master control means messages;

means for executing a network task for communicating with said one second station;

data interface means between said main task and said network task for storing second station response information, said network task gathering said response information, said main task accessing said response information to generate a response message to be sent to said master control means; and

said data interface means comprises a data table of sections, each section of the table allocated to store response information for one of said plurality of second stations.

7. The system of claim 6, in which said response information comprises status data, error data, and digitized representations of analog data.

8. A distributed radio communication and control system, comprising:

master control means for controlling communications with a plurality of remotely-located first stations and a plurality of remotely-located second stations, each of said first stations having a first station address and each of said second stations having a second station address the master control means generating master control means messages, each said message having a destination address;

master radio means adapted to receive said master control means messages for transmitting said master control means message to one of said first stations when one of said first station addresses corresponds to said destination address and for sending a response message to said master control means from said one first station;

supplemental control means for monitoring said master control means messages and for determining whether one of said second station addresses corresponds to said destination address, said supplemental control means transmitting a supplemental control means message to one of said plurality of remotely-located second stations when said one of said second station addresses corresponds to said destination address, said supplemental control means sending a response message to said master control means based upon a response from said one of said plurality of remotely-located second stations to said supplemental control means message; and

means for selectively coupling either one of a master radio means communicating channel and a supplemental control means communication channel to said master control means across which a response message is sent;

wherein said supplemental control means controls the coupling means to select the supplemental control means communication channel when said destination address corresponds to a second station address; and

wherein said supplemental control means comprises;

a) means for executing a main task for monitoring and testing said master control means messages;

b) means for executing a network task for communicating with said one second station; and

c) data interface means between said main task and said network task for storing second station response information, said network task gathering said response information, said main task accessing said response information to generate a response message to be sent to said master control means.

9. The system of claim 8, in which said master radio means is disabled from transmitting a master control means message to a first station when one of said second station addresses corresponds to said destination address.

10. The system of claim 9, in which said master radio means is enabled for transmitting a master control means message to a first station when one of said second station addresses does not correspond to said destination address.

11. The system of claim 10, in which said supplemental control means controls said disabling and enabling of said master radio means.

12. The system of claim 11, in which said master radio means and said supplemental control means are located at a common site remote from said master control means.