Communications module base repeater

• US 5,978,371 A
• Filed: 03/31/1997
• Issued: 11/02/1999
• Est. Priority Date: 03/31/1997
• Status: Expired due to Term

• Current Assignee: Elster Electricity LLC (Honeywell International Inc.)
• Original Assignee: ABB Power T&D Co Inc (ABB Limited)
• Inventors: York, Ted H., Mason, Robert T. Jr.
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Sam, Phirin
• Application Number:
  US08/828,539
• Time in Patent Office: 946 Days
• Field of Search: 370/279, 370/315, 370/364, 370/389, 370/395, 370/397, 370/399, 370/400, 370/402, 370/421, 370/423, 370/501, 370/320, 370/278, 370/282, 370/293, 370/312, 370/378, 370/379 , 370/382, 370/383, 370/392, 340/505, 340/870.02, 455/90, 455/402, 395/702, 395/82, 395/824, 395/825, 395/800.35, 395/566, 395/559
• US Class Current: 370/389
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer

Abstract

A repeater communications module (RCM) that enhances signals in a communications network comprises a processor coupled to a communications medium and optionally to a host application. The RCM operates in one of two modes: (1) interface or host application controlled, and (2) standalone. In the interface mode, the RCM receives packets from a host application, modifies the packets and transmits message packets in accordance with a transmit role table (TRT). In standalone mode, the RCM initiates packets and transmits message packets in accordance with the TRT. All RCMs can be configured to repeat message packets which are received from the communications medium in accordance with a repeater role table (RRT).

Claims

1. A communications module comprising:

(a) a processor that controls the reception from the host application, modification and transmission of message packets in accordance with a prescribed transmit role table (TRT); and

(b) a memory operatively coupled to said processor and containing said TRT;

wherein said TRT comprises a plurality of entries, wherein each entry comprises a destination house code, a destination device address, and a transmit repeater role identifier (TRRI), wherein said destination house code and destination device address identify a specific destination device and its house address, and wherein said module is capable, through said processor and TRT, of modifying said message packets to thereby determine a route to a destination device for each packet.

2. A communications module as recited in claim 1, wherein said communications module is operatively coupled to the host application, and wherein said processor is programmed to compare a first field within a packet received from the host application to said destination house codes, and to compare a second field within the packet received from the host application to said destination device addresses, and to copy the TRRI corresponding to the TRT entry having codes matching the destination house code and destination device address to a repeater role identifier (RRI) field in said packet, and then to transmit the packet, wherein the packet is to be received by a repeater or destination device depending upon the addresses and RRI contained in the packet.

3. A communications module as recited in claim 1, further comprising a repeater role table (RRT) stored in said memory, wherein said RRT is employed by said module when said module is functioning as a repeater.

4. A communications module as recited in claim 3, wherein said repeater role table comprises a plurality of entries, each said entry comprising a source house code, a source device address, a destination house code, a destination device address, a receive repeater role identifier (RRRI) and a transmit repeater role identifier (TRRI);

wherein said source house code and source device address identify a specific source device and its house address, said destination house code and destination device address identify a specific destination device and its house address, and the RRRI identifies when the repeater is to respond to a message between the source and destination devices.

5. A communications module as recited in claim 4, wherein said processor is programmed to compare prescribed fields within the packet to said source house codes, source device addresses, destination house codes, and destination device addresses;

to identify an RRT entry having matching source and destination address and house codes;

to compare an RRI field in said packet to said RRRI in the identified entry;

to ignore the packet if said RRI field does not match said RRRI in the identified entry;

to ignore the packet if a matching set of device addresses and house codes is not found in the RRT; and

, if said RRI field does match said RRRI in the identified entry, to insert the TRRI in said identified entry in said packet and to re-transmit the packet.

6. A communications module as recited in claim 1, wherein the module is configurable to function as a repeater, and said processor is programmed to act in response to an open pipe packet indicating an open pipe procedure as follows:

if the module is functioning as a repeater and determines that the open pipe procedure is to be repeated, the module sets a busy filter, sends an immediate acknowledgment (IACK) to a transmitting device, wherein the transmitting device may be a source device or a repeater, and then re-transmits the open pipe packet;

if the module is a source or destination device, once the open pipe procedure exchange is completed, the module sets an open pipe bit in all packets except the last packet of a response message, and, in the last packet of a response, the end of a normal message sequence is indicated by the clearing of the open pipe bit.

7. A communications module as recited in claim 1, wherein said module is programmable to function as a repeater for repeating message packets, as a standalone source device capable of initiating message packets, or as a device coupled to a host application and capable of transmitting message packets initiated by the host.

8. A repeater communications module (RCM) for repeating message packets, comprising:

(a) a processor that controls the reception and re-transmission of message packets in accordance with a prescribed repeater role table (RRT); and

(b) a memory operatively coupled to said processor and containing said RRT;

wherein said RRT comprises a plurality of entries, each said entry comprising a source house code, a source device address, a destination house code, a destination device address, a receive repeater role identifier (RRRI) and a transmit repeater role identifier (TRRI);

wherein said source house code and source device address identify a specific source device and its house address, said destination house code and destination device address identify a specific destination device and its house address, and the RRRI identifies the repeater which is to re-transmit the message packet; and

wherein said processor is programmed to compare prescribed fields within a packet to said source house codes, source device addresses, destination house codes, and destination device addresses, and to determine whether to ignore the packet or to modify and transmit the packet.

9. An RCM as recited in claim 8, wherein said processor is programmed to compare prescribed fields within a packet to said source house codes, source device addresses, destination house codes, and destination device addresses;

to identify an RRT entry having matching source and destination address and house codes;

to compare an RRI field in said packet to said RRRI in the identified entry;

to ignore the packet if said RRI field does not match said RRRI in the identified entry; and

, if said RRI field does match said RRRI in the identified entry, to insert the TRRI in said identified entry into said packet and to transmit the packet.

10. A consumer electronics bus (CEBus) system comprising a plurality of repeater communications modules (RCMs) each of which is in communication with both an associated electricity meter of a residence and, via a communications medium, to at least one other RCM, wherein said RCMs are configurable to function as a repeater for repeating message packets, as a source device for initiating message packets, or as a device coupled to a host application for transmitting message packets initiated by the host, wherein at least one RCM comprises:

(a) first means for controlling the reception, modification and forwarding of message packets, wherein said first means operates in accordance with a transmit role table (TRT) when the RCM is functioning as a source or is coupled to and controlled by a host application and the host application is acting as a source;

(b) second means for receiving message packets and re-transmitting said message packets in accordance with a repeater role table (RRT) when the RCM is functioning as a repeater; and

(c) a memory operatively coupled to said first and second means, wherein said memory stores said TRT and RRT.

11. A system as recited in claim 10, wherein said transmit role table comprises a plurality of entries, wherein each entry comprises a destination house code, a destination device address, and a transmit repeater role identifier (TRRI), wherein said destination house code and destination device address identify a specific destination device and its house address.

12. A system as recited in claim 11, wherein, when said RCM is a source device, said processor is programmed to compare a first field within the packet to said destination house codes, and to compare a second field within the packet to said destination device addresses, and to copy the TRRI corresponding to the TRT entry having a matching destination house code and destination device address to an RRI field in said packet, and then to transmit the packet.

13. A system as recited in claim 10, wherein said repeater role table comprises a plurality of entries, each said entry comprising a source house code, a source device address, a destination house code, a destination device address, a receive repeater role identifier (RRRI) and a transmit repeater role identifier (TRRI);

wherein said source house code and source device address identify a specific source device and its house address, said destination house code and destination device address identify a specific destination device and its house address, and the RRRI identifies the repeater that is to re-transmit the message packet.

14. A system as recited in claim 13, wherein said RCM is programmed to compare prescribed fields within the packet to said source house codes, source device addresses, destination house codes, and destination device addresses;

to identify an RRT entry having matching source and destination address and house codes;

to ignore the packet if a matching set of device addresses and house codes is not found in the RRT;

to compare an RRI field in said packet to said RRRI in the identified entry;

to ignore the packet if said RRI field does not match said RRRI in the identified entry; and

, if said RRI field does match said RRRI in the identified entry, to insert the TRRI in said identified entry in said packet and to re-transmit the packet.

15. A system as recited in claim 10, wherein re-transmission of a message packet by said RCM includes enhancing the packet.

16. A system as recited in claim 10, wherein the communications medium is a member of a group consisting of power line, twisted pair, coaxial cable and wireless media.

17. A system as recited in claim 10, wherein the RCM is integrated with a device or an appliance such that said device or appliance maintains its existing functionality while adding the capabilities of the RCM.

18. A system as recited in claim 10, wherein the system is configured to establish a complete end-to-end communication path between source and destination devices prior to transmission of a message, and wherein each RCM involved in a given communication session is dedicated to that session until the session is complete.

19. A system as recited in claim 10, wherein each communications module is programmed to dedicate itself to a message transfer between only a specified number of devices at a time by setting a busy filter, and to instruct other devices which attempt to use a communications module with a set busy filter to retry their message at a later time.

20. A system as recited in claim 10, wherein each communications module is programmed to retry messages which are known to have not reached a next communications module or destination device.

21. A system as recited in claim 10, wherein each communications module is programmed to use a channel access time of 8 CEBus unit symbol times (USTs) for repeat packets, whereby a repeated packet is given higher priority than that given to other packets.

22. A communications module (CM) for sending message packets via one or more repeaters and a communications medium to any of a plurality of destination devices, comprising:

(a) a first processor means for communicating with a host application and controlling the reception, modification and transmission of message packets received from the host application in accordance with a first transmit role table (TRT);

(b) a second processor means, which is not in communications with said host application, for generating a message packet and transmitting the message packet in accordance with a second transmit role table (TRT); and

(c) a memory operatively coupled to said first processor means, wherein said memory stores said first TRT and provides access thereto to said first processor;

wherein each said TRT comprises a plurality of entries, wherein each entry comprises a destination house code, a destination device address, and a transmit repeater role identifier (TRRI), wherein said destination house code and destination device address identify a specific destination device and its house address, and wherein said CM is capable of modifying said message packets to thereby determine a route to a specific destination device for each packet.

23. A communications module as recited in claim 22, wherein said communications module is operatively coupled to a host application, and wherein said first processor means is programmed to compare a first field within a packet received from the host application to said destination house codes, and to compare a second field within the packet received from the host application to said destination device addresses, and to copy the TRRI corresponding to the TRT entry having a matching destination house code and destination device address to an RRI field in said packet, and then to transmit the packet, wherein the packet is to be received by a repeater or destination device depending upon the addresses and RRI contained in the packet.

24. A method for operating a communications module having access to a prescribed transmit role table (TRT) that includes a plurality of entries, each entry comprising a destination house code, a destination device address, and a transmit repeater role identifier (TRRI), wherein said destination house code and destination device address identify a specific destination device and its house address, the method comprising the steps of:

comparing a first field within a packet to said destination house codes;

comparing a second field within the packet to said destination device addresses;

copying the TRRI corresponding to the TRT entry having a matching destination house code and destination device address to a repeater role identifier (RRI) field in said packet; and

transmitting the packet.

25. A method as recited in claim 24, wherein said communications module further has access to a repeater role table (RRT) containing a plurality of RRT entries, each said RRT entry comprising a source house code, a source device address, a destination house code, a destination device address, a receive repeater role identifier (RRRI) and a transmit repeater role identifier (TRRI), wherein said source house code and source device address identify a specific source device and its house address, said destination house code and destination device address identify a specific destination device and its house address, wherein the method further comprises the steps of:

comparing prescribed fields within the packet to said source house codes, source device addresses, destination house codes, and destination device addresses of said RRT;

identifying an RRT entry having matching source and destination address and house codes, and ignoring the packet if a matching set of device addresses and house codes is not found in the RRT;

comparing an RRI field in said packet to said RRRI in the identified entry;

ignoring the packet if said RRI field does not match said RRRI in the identified entry; and

if said RRI field does match said RRRI in the identified entry, inserting the TRRI in said identified entry in said packet and transmitting the packet.

26. A method as recited in claim 25, further comprising responding to an open pipe packet indicating the initiation of an open pipe procedure as follows:

if the module is functioning as a repeater and determines that the open pipe packet is to be repeated, the module sets a busy filter, sends an immediate acknowledgment (IACK) to the transmitting device, wherein the transmitting device may be a source device or a repeater, and then transmits the packet;

if the module is a source or destination device, once an open pipe procedure exchange is completed, the module sets an open pipe bit in all packets except the last packet of a response message, and, in the last packet of a response, the end of a normal message sequence is indicated by the clearing of the open pipe bit.