GB2056731A - Building control system - Google Patents

Abstract

A building control system for controlling heating, lighting, etc. from a central station comprises a conventional central station 10 and remote stations 14, 15, etc. connected together by means of an antenna wire 11 which is used primarily for distributing entertainment (radio and TV) to a plurality of rooms in e.g. a hotel. The central station generates 15-bit messages consisting of an 11-bit address followed by a 4-bit control function, and each remote station includes a comparator for comparing the transmitted addresses with a preset address of that remote station, and decoding means for recognizing and carrying out the following control function if an address match is detected. <IMAGE>

Description

SPECIFICATION Building control system This invention relates to the trasmission of digital data in building control systems.

Energy management, and fire and security supervision, are today being controlled by computer data processing techniques. For fire and security supervision, such techniques allow a high degree of security in monitoring the fire and security points within a building to insure that all alarms will be brought to the attention of the security personnel in the building and that all lines running between the central station where the personnel are located and the remote fire and security sensing points are supervised for attempted breaches. In energy management systems, these techniques also allow the control of a building's air conditioning and energy consuming loads in the most efficient manner in accordance with changing conditions. Such schedules as optimum startup, load cycling and load shedding can reduce the total energy consumption of a building.

However, it is much easier to install such systems in newly constructed buildings than in existing buildings and even then the cost of installing wire dedicated specifically to the transmission of information between the central station and its remote stations adds materially to the overall cost of the systems. In small buildings, the added cost of wiring can mean the difference between installing such energy saving and security equipment or suffering the high cost from using unnecessary energy and potential losses from thefts and burglaries.

Moreover, in such buildings as motels, hotels and the like, guests often check out of their rooms without turning off lights, reducing the heating or cooling load by appropriate adjustment of the thermostat, or shutting off electrical appliances such as radios andXtelevi- sions. There is a substantial amount of energy being wasted to run these loads even though the room is not occupied.

In order to take advantage of the energy savings attendant with energy management systems, especially in existing buildings, it is desirable to develop a system which requires no extra wiring between the central station and its remote stations. Wireless transmission of radio frequency signals suffers the disadvantges of governmental regulations and expensive signal transmitting and receiving equipment. It has been suggested that the power lines running throughout the building be used to carry the digital information necessary for energy management and fire and security supervision. However, power line carrier devices are susceptible to noise on the line and can thus randomly cycle the controlled loads in an energy wasteful manner. It has further been suggested that the telephone lines running throughout a building complex can be used to carry this information.However, no one has suggested using the antenna wiring system that runs from the rooftop antenna to nearly every room within such buildings as hotels and motels.

Accordingly the invention provides a building control system comprising: an antenna wire system utilized primarily to distribute entertainment to a plurality of rooms; a central station, coupled to the antenna wire system, for transmitting messages consisting of an address generated by an address generator followed by control information generated by a control unit; and one or more remote stations, coupled to the antenna wire system, each including address match means for recognizing when an address transmitted by the central station matches a preset address identifying the remote station, and a decoding unit for carrying out a control function in response to the control information following an address which matches the preset address.

A system in accordance with the invention will now be described, by way of example, with reference to the accompanying drawing, which is a block diagram of the system.

Referring now to the drawing, central station 10 is connected to antenna wire system 11 running through a building such as a motel or hotel and may be located in the office or other convenient room of the building. Central station 1 0 is connected to antenna line 11 by connector 1 2. Within the guest or other rooms of the building are located remote stations such as 1 4 and 1 5 connected to the antenna wire system 11 by connectors 1 7 and 1 8 respectively.

Central station 10 comprises an address and control generator in the form of transmitter circuit 1 9 connected to antenna system 11 by single channel modem 20. Transmitter 1 9 transmits 1 5 bit messages or words to the remote stations. Eleven of the bits transmitted by transmitter 1 9 are comprised of the address for the specific remote station with which central station 20 wishes to communicate. This address is selected by address keyboard 21. The other four bits of the message transmitted by transmitter 1 9 through modem 20 are selected by control input 22 which may provide, for example, start-stop functions for the loads of remote stations.Voice transmitter 23 connected to microphone 24 may also be connected to transmitter 1 9 for transmitting voice messages over antenna wire system 11 to the remote stations.

Remote station 1 4 comprises receiver 28 connected on one side to antenna wire system 11 through single channel modem 29 and on the other side to loads such as fan 30 and signal light 31. Remote station 1 5 comprises receiver 32 connected on one side to antenna wire system 11 through single channel modem 33 and on its other side via voice receiver 34 to speaker 36.

Messages, which are constructed of an address portion and a control portion, are transmitted by central station 10 to antenna wire system 11 and received by remote stations.

The receiver in each remote station compares the address received from central station 10 with its own specific address (set by its respective keyboard such as 28A, 32A) so that each remote station can determine whether it is the one selected by central station 10 to perform a control function. The selected remote station will then operate on its loads according to the control instructions in the control portion of the message transmitted by central station 10. When the system is to be used in motels and hotels, the loads may be the heating and refrigeration units, lights, radios, televisions and the like located in the guest rooms. They may also be speakers, as suggested by remote station 15, for direct oral communication with the maids cleaning the room or the guests staying in the room.

The transmitter 1 9 and the receivers 28 and 32 may each take the form of a standard transmitter/receiver integrated circuit. The transmitter circuit generates fifteen bit Manchester code words from the eleven address inputs and four control inputs. Circuit 1 9 has a control pin connected to ground, so making it a transmitter, and has an RC network connected to it to establish the frequency for the master oscillator within integrated circuit 1 9.

On energizing a Start/Data Input pin, the address selected by the switch bank will be transmitted out through the signel channel model 20 to antenna wire system 11. The keyboard 21 is a bank of 11 switches settable to the address of the remote station with which cental station is to communicate. The control information, forming the last four of the fifteen bit message transmitted by transmitter 19 to antenna wire system 11, is a 4bit signal produced by the control input unit 22. This control information may include Start-Stop information for the loads controlled by the remote stations.

At the remote station 14, modem 29 receives the messages transmitted over antenna wire system 11 from central station 10 and feeds these messages to the receiver 29, which is the same circuit as receiver 19, but has its control pin connected to a positive supply to condition it as a receiver. An RC network is connected to it to select the frequency of the master oscillator within receiver 29. A set of eleven pins of receiver 29 are connected to switchbank 28A, which is preset to the specific address used to identify remote station 14. When the message transmitted by central station 10 is received by modem 29 and supplied to receiver 28, receiver 28 compares the received address with the address established by switchbank 28A. If the addresses match, then the receiver 28 feeds the last four bits of the message to a shift register and decoder circuit 64, which controls the loads such as light 31. For additional loads at a remote station, additional outputs, for demultiplexing and power switching, from circuit 64 are used to decode the information from receiver 28 to determine which load to control and how the load should be controlled. As shown, a maximum of 1 6 loads may be simultaneously controlled per station.

Claims (6)

1. A building control system comprising: an antenna wire system utilized primarily to distribute entertainment to a plurality of rooms; a central station, coupled to the antenna wire system, for transmitting messages consisting of an address generatred by an address generator followed by control information generated by a control unit; and one or more remote stations, coupled to the antenna wire system, each including address match means for recognizing when an address transmitted by the central station matches a preset address identifying the remote station, and a decoding unit for carrying out a control function in response to the control information following an address which matches the preset address.

2. A system according to Claim 1, wherein the central station and the remote station or stations are coupled to the antenna wire system through respective modems.

3. A system according to either previous claim, wherein the central station includes a first set of switches comprising the address generator and settable to a desired address, and a second set of switches comprising the control unit and settable to define a desired control function.

4. A system according to any previous claim, wherein the or each remote station comprises a set of switches preset to define the preset address, and a comparator for comparing the preset address with addresses received from the central station.

5. A system according to Claim 4, wherein the comparator forms part of an integrated circuit receiver unit.

6. A building control system substantially as heein described and illustrated.