GB2289996A - Remote control of power supply to loads - Google Patents

Abstract

Loads such as lights 2 or heating loads connected to a mains power supply system are controlled by relays 4 responsive to the operation of an input node 8 or infra red signals transmitted to an infra red receiver 22 from a portable unit 24 or a unit 29 and supplied to the relays via a data bus 14. The system enables loads to be controlled without the need to locate a wall switch. System parameters such as temperature or illumination threshold levels may be transmitted from the portable unit and stored in an interface unit 20. <IMAGE>

Description

BUS CONTROLLED ELECTRICAL MAIN8 SUPPLY This invention relates to a bus controlled electrical mains supply for a building.

In a bus controlled electrical mains supply system for example the Echelon system, output nodes, which are connected to receive electrical power from mains power conductors, are controlled by input nodes. The input nodes communicate with the output nodes by means of control signals sent via a bus separate from the mains power conductors. Thus, for example, a lighting unit (output node) can be controlled by one or more switches and/or photodetectors (input nodes). The association between the input nodes and the output nodes is made by a process referred to as "configuring" in which the nodes are identified by pressing a push button on the unit. The configuring process then programs the nodes so that the output node is operated in response to signals placed on the bus by the input nodes bound thereto.

In accordance with the invention, there is provided a bus controlled electrical mains supply system in which output nodes include control means connected to control supply of electrical power from mains power conductors, operation of said control means being determined by input nodes, the input nodes communicating with the output nodes by means of control signals sent via a bus, wherein one or more of said input nodes is responsive to infra red signals including channel identity information, said system including: at least one portable manager unit for transmitting infra red signals, in which the channel information can be set by means normally accessible from outside the unit, said one or more infra red responsive nodes including means for selecting it or them to enable system parameters to be entered by infra red signals received by the node(s).

In a preferred example, it is proposed to provide input nodes responsive to an environmental parameter, e.g.

temperature or light level, so that the temperature of an area can be controlled, a level of illumination above which use of the lights is not permitted, or so that lights can be switched on and off automatically according to the light level, and so on. System parameters defining different levels of temperature and different light levels may be set in different areas controlled by different input nodes.

Conveniently the system may include at least one portable user unit pre-set to transmit infra red signals containing only one channel identity signal. A user may thus, for example, be able to operate a section of lights in a large office without the need to locate respective wall switches.

Entering the system parameters preferably includes setting an input node to respond to a respective infra red channel identity. An input node may thus be set to receive signals from an infra red transmitter issued to a user. The user unit is not capable of setting system parameters so the system parameters remain under the control of the system management unit.

Most preferably, an input node includes a sensor for sensing an environmental parameter, and setting the system parameters includes setting a threshold of said environmental parameter at which the node will place a signal on the bus.

Alternatively or additionally, an input node includes a sensor for sensing the level of an environmental parameter and means for placing a data signal representative of the level on the bus, and setting the system parameters includes setting an output node to change state if a threshold level is crossed.

Examples of an environmental sensor are a photo sensor or a temperature sensor.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, which is a block diagram of a bus controlled electrical supply system embodying the invention.

Referring to the drawing, electrical power is supplied to a lamp from a ring main L,N via control means in the form of a relay 4. The relay 4 is contained in an output node 6. Operation of the control means in the form of relay 4, to control (in this case switch) the supply of electrical power to the lamp 2, is controlled by one or more input nodes of which two kinds are shown at 8 and 10. The node 8 is equivalent to a wall-switch. The node 10 is ceiling mounted and contains a photocell 12 to control operation of the lamp. The input nodes communicate with the output nodes via a data bus 14. In the present example the bus 14 is separate from the mains. In other examples (not illustrated) the mains supply is modulated by the necessary signals and thus acts as a bus.

Initially, there is no association between input nodes and output nodes. In order to arrange the system so that input units can operate output nodes the system must be configured. In response to signals transmitted over the bus a configuration unit 16 programs the input nodes and/or the output nodes so that the one responds to signals from the other. Thus, for example, the output node 6 may be given a list of input node identities to which it is to respond. In that case, operation of the input node places its identity signal on the bus. The output node may have been programmed with the function of the input node, in which case it may recognise that the input node is, say a switch and may respond accordingly to change the state of its relay between open and closed. Whether the relay should be open or closed may be specified in a data signal accompanying the identity signal.Alternatively, a signal specifying the function of the input node as, say, a switch may also accompany the identity signal. Alternatively or additionally, the input node may be programmed to place on the bus the identity signals of the output nodes which should respond to it.

This is accompanied by a signal specifying the function of the input node and optionally whether the relay should be open or closed.

The configuration unit 16 may have a keyboard or key pad by which it is operated. It is only required during the configuring process and may be removed from the system after or between configuring operations. Input and output nodes to be bound together are first selected. This may be done from the configuration unit by specifying the identities of the nodes from the keyboard or key pad at the configuration unit. More conveniently, the nodes are selected by operating a push button 18 on each selected node. This sends the identity of each node to the configuration unit via an interface 20. Once all the nodes had been selected, in a conventional system, the configuration process would need completing by entering code into the configuration unit via its keyboard or key pad.

The light 2, or in other cases the heating, can be operated by an infra red transmitter without the need to locate a wall switch. To this end the input node 10 has an infra red receiver 20. Selecting the node 10 by means of its push button arms is to treat the next infra red channel identity signal as one to which it should in future respond.

A portable manager unit 24 has a keypad 26 to which the unit is responsive to transmit a corresponding infra red channel identity signal. The pre-selected node 10 decodes the signal in a decoder 25 and stores the identity in the interface unit 20. When that channel identity is received subsequently, the interface will illuminate an LED 27 and place a signal on the bus to which those nodes which are associated by the configuration to receive that channel identity at the node 10 will respond. Thus, a number of output nodes, such as 6, may be operated by sending the channel identity signal to the input node 10. Heating or lighting may thus be switched on or off from a user's work station without the need to locate a wall switch.

It is not necessary for the user to have the means to select different channels, indeed it may be undesirable to provide that facility. All the user needs is an infra red transmitter 29 which is pre-set to the channel identity required to operate the node 10. One push button 31 is required. The channel identity may be pre-set by say DIL switches.

Once the system has been configured it may be desired to set temperature or illumination levels for different areas. To this end, the manager unit 24 also has a set of push buttons 28 by which a respective threshold level representative infra red signal may be sent to the node 10. The threshold level is stored in the interface unit 20. The interface unit is also responsive to the output of the photocell 12. When the output of the photocell 12 indicates that the threshold has been crossed the interface unit places a suitable signal on the bus together with its identity and its function. An output node will recognise the identity as one to which it should respond, and will react to the threshold crossing as it has been programmed in the configuring process, e.g. it may prevent operation of a wall switch or a user infra red unit from turning on the light 2 unless the light level is below the threshold.

When the present system is being configured, if the nodes to be associated are selected by push buttons on the units, it is convenient to send code via the manager unit 28 and the infra red receiver 22 to operate the configuration unit 16 remotely.

Claims (7)

Claims:

1. A bus controlled electrical mains supply system in which output nodes include control means connected to control supply of electrical power from mains power conductors, operation of said control means being determined by input nodes, the input nodes communicating with the output nodes by means of control signals sent via a bus, wherein one or more of said input nodes is responsive to infra red signals including channel identity information, said system including: at least one portable manager unit for transmitting infra red signals, in which the channel information can be set by means normally accessible from outside the unit, said one or more infra red responsive nodes including means for selecting it or them to enable system parameters to be entered by infra red signals received by the node(s).

2. A system as claimed in claim 1, including at least one portable user unit pre-set to transmit infra red signals containing only one channel identity signal.

3. A system as claimed in claim 1 or 2, wherein entering the system parameters includes setting an input node to respond to a respective infra red channel identity.

4. A system as claimed in any preceding claim, wherein an input node includes a sensor for sensing an environmental parameter, and wherein setting the system parameters includes setting a threshold of said environmental parameter at which the node will place a signal on the bus.

5. A system as claimed in any of claims 1 to 3, wherein an input node includes a sensor for sensing the level of an environmental parameter and means for placing a data signal representative of the level on the bus, and wherein setting the system parameters includes setting an output node to change state as a threshold level is crossed.

6. A system as claimed in claim 4 or 5, wherein the sensor is a photo sensor or a temperature sensor.

7. A system as claimed in any preceding claim, which is responsive to an infra red signal transmitted by the manager unit to associate a number of selected nodes.