CA2363217A1

CA2363217A1 - System and method for environmental monitoring and energy control

Info

Publication number: CA2363217A1
Application number: CA002363217A
Authority: CA
Inventors: Ian C. Campbell
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-22
Filing date: 2001-11-22
Publication date: 2003-05-22

Abstract

An environmental monitoring and control system for regulating the environmental conditions of an indoor environment. The system comprises a local area network of Universal Detector-Controllers (UDCs), each UDC device comprising a plurality of environmental monitoring sensors for measuring indoor air composition and characteristics, and a microprocessor for acquiring the sensor measurement data, for recording the measurement data on a datalogger, and for controlling actuators (such as a gas shut-off valve) if required. Over a telecommunications network, a remote computer systems both monitors sensor measurement data and provides to each of the UDCs in the series, a set of customized operating in thereby optimizing the energy usage through a building.

Description

SYSTEM AND METHOD FOR ENVIRONMENTAL
MONITORING AND ENERGY CONTROL
FIELD OF THE INVENTION
The invention relates to the field of indoor environmental monitoring and energy control.
BACKGROUND OF THE INVENTION
io In the following specification, indoor environments refer to interior spaces of buildings of all description including homes, offices, schools, hospitals, fire and police stations, government facilities, warehouses, etc.
~s In the following specification, environmental conditions refer to indoor air characteristics and composition. More generally, however, environmental conditions include any measurable characteristic of an indoor environment by means of an electronic sensor. Examples of environmental conditions include gas concentration, temperature, relative humidity, and the like.
In the following specification, an actuator refers to any electronically activated device used to control or otherwise adjust an environmental condition.

Examples of actuators include gas valves, ceiling fans, exhaust fans, stepper motors, heaters, boilers, humidifiers, dehumidifiers, and ventilation systems.
The environmental conditions of indoor environments should be s monitored for three reasons.
Firstly, the environmental conditions of buildings should be monitored for potential gas leaks in order to protect buildings from fires and explosions due to the ignition of combustible gases and ensure the safety of the building's to occupants. It is particularly important to monitor for gas leaks following earthquakes, tornadoes, or other such natural disasters where significant damage to buildings and injury to people due to gas leaks is known to occur.
Secondly, indoor environmental conditions should be monitored to ensure is a healthy environment for its occupants. Not only should the composition of the air be monitored for poisonous gases, other seemingly benign characteristics of the indoor environment such as relative humidity and temperature should also be monitored in order to detect and avoid, for example, conditions conducive to the growth of mold. Typically, workplace environments are required to comply with 20 occupation health and safety standards established by the government, or other governing board; ideally workplace environments should be monitored on a continual basis in order to verify compliance with these standards.

2 Thirdly, as reliable power resources decline and as the cost of energy increases, it is advantageous for tighter control of indoor environment conditions in order to restrict wasteful energy usage. Ideally, many different spaces of a building should be monitored to ensure each space makes most efficient use of s energy. There are several difficulties in achieving a compromise between energy efficiency and comfort of building's occupants. In particular, it is necessary to accommodate wide ranges of environmental preferences of the building's occupants. Furthermore, in many buildings, a central thermostat controls all heat directed throughout a building; it is necessary that a building be balanced by to adjusting the heat directed to each region of the building in order to accommodate the particularities of the building and the preferences of the building's occupants. The technique of balancing a building is not determinate;
the technique relies on trial and error.
Is The prior art has not provided a satisfactory solution addressing the foregoing concerns. As such, many buildings do not include any kind of environmental monitoring and control systems beyond those which may be required by building codes such as smoke alarms, heat detectors and automatic sprinkler systems.
Many different types of electronic-based sensors for measuring a characteristic of an indoor environment and providing a signal indicative of the measurement have been developed. Typically, such sensors provide an

3 analogue signal indicative of the measured characteristic. Some sensor types include combustible gas sensors (for measuring the concentration of natural gas, propane, gasoline vapor, etc), carbon dioxide gas sensors, carbon monoxide gas sensors, accelerometers, temperature sensors, relative humidity sensors, and s the like.
Such sensors have been incorporated into various types of detector-controller systems described as follows:
to As mentioned above, conventional environmental condition detectors such as smoke detectors and heat sensors have been widely used in many new buildings thanks to government-enforced building regulations. These types of detectors tend to operate independently from one another in that besides a power source, the detectors are both completely self-sufficient and operate ~s completely separately from one another; the detectors neither receive instruction from an external source, nor include means for providing data to an external source. Conventionally, a plurality of detectors may be installed at various locations throughout a building. Once a sensor detects a concentration of gas above some predetermined tolerance (usually established by a National 2o Standards Association, or other such governing board), typically an alarm, or buzzer is sounded in order to alert the building's occupants of the potentially dangerous situation so that the occupants may take steps to correct the problem.
Such detectors are limited in a number of ways. Because they cannot be readily

4 recalibrated once sensor measurements should begin to drift, and because they do not make any attempt to diagnose the cause of the dangerous reading, nor do they provide any suitable means for remedying the situation, such detectors are known to emit false alarms. While false alarms are disruptive in the best of s situations, in places such as hospitals, false alarms can cause considerable disturbance.
A more advanced type of detector-controller of the prior art includes means for activating an auxiliary actuator device in response to a measured gas to levels. One type of previously known detector-controller, for example, monitors the concentration of natural gas present in air and may automatically activate an automatic gas shut off valve once the natural gas concentration is measured above the allowable tolerance. As with the prior art detectors previously discussed, these types of detector-controllers operate independently from one ~s another. These types of detector-controllers may include one or more types of sensors although tend to be limited to activating one actuator device such as a gas shut off valve.
This type of system needs to be hard wired to a central power supply and 2o accordingly is both difficult to install and is subject to voltage fluctuations. This system does not incorporate a backup battery power source in case of power failure. As discussed above, it is especially important to monitor the s environmental conditions of building in situations where power may have been disrupted.
More recently, expensive industrial computers such as Direct Digital s Controls (DDCs) have been used to monitor and control indoor environmental conditions. Typically several sensors distributed at various locations in a building are independently wired to the DDC. Based on the data received by the sensors, the DDC may activate one or more actuators (such as a ceiling fan).
Actuators also tend to wired directly to the DDC. As stated above, the system is ~o both is very expensive and is not suitable for use in a home. DDC systems also require customized software. The system is difficult to install (as each sensor and each actuator requires a direct connection to the DDC), and is difficult to upgrade and modify.
~s One system of the prior art is described in United States Patent 6,266,579 (Baraty, 2001 ). This patent relates to a system for reducing damage to buildings following some type of disaster, such as an earthquake. The patent describes a system where the flow of various utilities (such as water, and gas) entering a building are monitored for indication of a leak. Upon detection of a leak, the flow 2o is automatically shut interrupted until such time that the danger is over.
Another system of the prior art, sold by Honeywell, aims to bridge the gap between a thermostat and a DDC by means of Demand Control Ventilation.

Honeywell's T7300 system is a commercial oriented programmable thermostat.
The system furthermore provides remote monitoring by a PC via a modem connected to a telecommunication network. The Honeywell system is relatively expensive due to complicated network software and protocol.
s SUMMARY OF THE INVENTION
It is an object of the present invention is to provide an effective system for protecting buildings from fires and explosions due to the ignition of combustible ~o gases and ensure the safety of the building' s occupants.
It is another object of the present invention to provide an effective system for monitoring and controlling indoor air quality to ensure a healthy environment for its occupants.
Is It is another object of the present invention to provide an effective system for tightly controlling indoor environmental conditions in order to restrict wasteful energy usage.
2o The present invention provides a system for monitoring the environmental conditions at a plurality of regions throughout a building and for controlling actuators in response to the monitored conditions in order to regulate an indoor environment. The system comprises a connected series of environmental monitoring Universal Detector-Controllers (UDCs), each UDC device comprising one or more sensors for measuring an environmental characteristic.
According to one aspect of the invention, the UDC comprises a s microprocessor connected to the power supply, and one or more environmental sensors for measuring an environmental characteristic and providing signals indicative of the environmental characteristics to the microprocessor.
According to another aspect of the invention, each UDC additionally to comprises control means for activating or otherwise regulating an actuator device in response to the magnitude of one or more measured environmental characteristics. By way of example of this aspect of the invention, an electronically activated gas valve may be automatically closed when the measured concentration of natural gas is greater than a predetermined tolerance i s level.
According to another aspect of the invention, each UDC additionally comprises means for relaying the power supply and communication with two neighbouring UDC devices, an upstream UDC device and a downstream UDC
2o device. More specifically, each of the UDCs of the system are connected in series forming a local area network. In particular, by means of modular RJ45 cables, and RS232 data communication techniques, each UDC in the series include means for relaying with two neighbouring UDCs (i) a power supply, (ii) s measurement data collected by the environmental condition sensors, and (iii) signals to activate actuators.
According to another aspect of the invention, a modem connected to the s series of UDCs may be used for communicating data between the series of UDC devices and a remote computer. That is, by means of a modem, data gathered by the series of UDC devices may be transmitted over a telecommunications network and monitored by a computer in a location which is geographically remote from the series of UDC devices. A single dedicated ~o computer station may be used to monitor and communicate customized operating instructions with multiple regionally distributed UDC network systems.
Communication with a remote computer facilitates the commissioning, troubleshooting, and optimization of UDC devices. Communication with a remote computer also greatly enhances energy control and conservation.
is According to another aspect of the invention, each UDC may additionally include a datalogger for recording environmental characteristic measurements provided by one or more environmental sensors.
2o According to another aspect of the invention, each UDC may additionally comprise a digital display for indicating the environmental condition measurements acquired by the microprocessor from one or more environmental sensors.

According to another aspect of the invention, the system includes an backup battery power supply.
s According to another aspect of the invention, each UDC is self-configuring in that each UDC along a system of connected series UDCs automatically detects its respective position whenever the system is powered up, whenever the system is reset, or whenever a UDC is added or replaced. That is, each UDC
may determine its own distinct address, thereby establishing the necessary to communication framework for both internal data communications with other UDCs in the system and external data communication over a telecommunications network to a remote PC. Effectively, the result is a scalable peer-to-peer local area network.
~s According to another aspect of the invention, each UDC is self-sufficient in that, besides a power source, each UDC within the system of UDCs is independently fully enabled. Each UDC includes a microprocessor for decision making capabilities and a datalogger for recording measurements. Each UDC
may either operate independently or within a larger system of UDCs.
According to another aspect of the invention, the connected series of UDCs are cooperatively operating in that the UDCs share a common power io supply, relay power, relaying communication both amongst themselves and with an external computer.
BRIEF DESCRIPTION OF THE DRAWINGS
s Figure 1 is a block diagram of the overall system layout according to the preferred embodiment of the invention. A plurality of Universal Detector-Controllers (UDCs) are connected in series by means of RJ45 cable thereby establishing a data communication network amongst the UDC devices.
~o Furthermore, each of the UDC devices in the series may be connected to up to four actuators as required to meet safety, indoor air quality and conservation needs of the specific building or machinery. In particular, each UDC device controls up to four switch modes or one stepper motor. Additionally, one actuator may be connected in the series of UDC devices; the actuator connected is in the series of UDC devices may be controlled by any of the UDC devices in the series. According to the preferred embodiment of the invention, the series of UDC devices is powered by a battery connected at one end of the linear series.
The battery may be connected to a battery charger powered in turn by power mains.
Figure 2 is a drawing of the hardware schematic of a Universal Detector-Controller (UDC) according to a preferred embodiment of the invention. An eight conductor RJ45 cable provides power from a downstream UDC device, receives data from a downstream UDC device in accordance with RS232 RX data communication standards, and transmits data to a downstream UDC device in accordance with RS232 TX data communication standards. Likewise, an eight conductor RJ45 cable relays power to an upstream UDC device, receives data s from an upstream UDC device in accordance with RS232 RX data communication standards, and transmits data to an upstream UDC device in accordance with RS232 TX data communication standards. Each UDC device includes a microprocessor for data processing according to user defined software, a seven segment digital readout, and up to eight environmental ~o sensors, whose readings are acquired for the microprocessor by a multiplexer. A
UDC device also includes up to four transistors for controlling four actuators.
Figure 3 is a block diagram of the software schematic according to the preferred embodiment of the invention. As outlined, the microprocessor runs ~s software which initializes the UDC electronics, registers, and RS232 communication, establishes a time of day clock, schedules measurement readings, takes action based on readings acquired from sensors, and displays information on the digital display.
2o Figure 4 is a flowchart showing the automatic sequencing and serialization of the series of Universal Detector-Controllers (UDCs). In particular, once a UDC
device has completed start up routines, a UDC device records the time of completion, and sends a completion signal to upstream UDC devices. Within a given time period, the sum total of accumulated signals is indicative of the network address.
Figure 5 is a block diagram depicting the system as integrated in a s hospital. The series of Universal Detector-Controllers (UDC) is connected to a gas shut off valve for shutting off the supply of natural gas at the source.
Figure 6 is a block diagram similar to the block diagram depicted in Figure

5. The block diagram depicts how the system is implemented as a carbon to dioxide environmental monitoring and control in a school. In particular, a UDC
installed in each room controls a damper in order to circulate fresh air through the room, as necessary.
Figure 7 depicts an example of oxygen trim on a combustion device. A
is Universal Detector-Controller (UDC) monitoring the concentrations of carbon monoxide, carbon dioxide, and oxygen concentration of a stack controls a gas valve and an air intake valve to ensure full and efficient combustion in a boiler with low oxygen concentration, low carbon monoxide concentration, and high carbon dioxide concentration in the stack.
Figure 8 shows the system configuration wherein a modem is used to communicate data between a series of Universal Detector-Controllers (UDC) and a remote monitoring computer.

Figure 9 shows a network configuration a series of Universal Detector-Controllers (UDC) are arranged in a "T" network.
s Figure 10 is a block diagram showing the "round-robin" monitoring schedule of the remote computer.
Figure 11 is block diagram showing the transmission of a synch token through a series of Universal Detector-Controllers (UDCs) in order to establish to communication priority.
Figure 12 shows a picture of the screen of the remote computer displaying results from a series of Universal Detector-Controllers (UDC) as transmitted over a telecommunications network .
Figure 13 is a diagram of the exterior of a Universal Detector Controller (UDC) device in accordance with the preferred embodiment of the invention.
The UDC includes three lights indicating various safety levels, and a three digit display for displaying sensor data.
DETAILED DESCRIPTION OF THE INVENTION

The system for monitoring and controlling indoor environmental conditions according to the invention comprises a connected series of Universal Detector-Controllers (UDCs). In this specification, the downstream direction of the connected series of UDCs shall refer to the direction along which the series s leads to a modem for communicating data (via a telecommunications network) with a remote computer system. That is, the most downstream UDC
communicates directly with the modem. Conversely, the upstream direction of the connected series of UDCs refers to the opposite direction along the series;
the most upstream UDC is the last along the series, and is the furthest from the to modem.
The environmental monitoring and control system according to the invention comprises one or more self-configuring, self-sufficient, cooperatively operating Universal Detector-Controllers (UDCs), each UDC comprising one or Is more environmental condition sensors, means for activating or regulating several external actuators, and means for communicating with a remotely located PC.
As shown in Figure 1, the UDCs are connected in series, forming a local area network. In general, each UDC includes a power supply, a microprocessor, 20 one or more environmental condition sensors, means for controlling up to four actuators, means for relaying power and communication data with an upstream, and a downstream UDC, and means for communicating with a with a remote PC.
IS

More particularly, according to the preferred embodiment of the invention, the power supply system comprises a backup battery and a battery charger. The 12 to 48 volt battery charger acquires power from a 110 volt AC power supply for charging a battery. The backup battery is used to provide a continuous supply of s power to the series of UDCs in case of main line power disruption or failure.
That is, the power supply system according to the preferred embodiment of the invention provides a relatively stable, continuous power supply to the UDCs, free from the fluctuations of the main power lines. In general, however, the power supply system need only provide a relatively stable, constant power supply of ~o any particular high voltage magnitude.
Alternatively, it is also contemplated that the central backup battery may be replaced by a plurality of backup batteries for delivering a backup power supply to individual UDCs. That is, each UDC may include its own backup Is battery power source.
Alternatively, it is contemplated several power supply systems may be connected together in series for delivering a power supply of greater magnitudes to the series of UDCs, thereby enabling greater numbers of UDCs to be 2o connected to a single series.
The power supply received by each UDC is processed for delivering a suitable power supply to the electronic components of the UDC. In particular, m according to the preferred embodiment of the invention, two voltage regulators are used for providing suitable power supplies; one voltage regulator produces a volt power supply used to power the digital components, the other voltage regulator produces a 2 volt power supply for powering the environmental s sensors. Suitable voltage regulators are manufactured by (part no. LM317T
(5V) and part no. 2574N-ADJ(2V)).
A suitable microprocessor for performing algorithms and other decision making processes required by each UDC is manufactured by Zilog (part no.
to Z86E4412VSC). This microprocessor has proven to be relatively inexpensive and provides ample programming facility. The timing of the microprocessor is regulated by a clock crystal. Based on the timing signals provided by a clock crystal, the microprocessor operates a time-of-day clock which is cumulative, even when the system is reset. As discussed below, the microprocessor both ~s receives and transmits data to both upstream and downstream UDCs, and acquires sensor measurements. The microprocessor is also coupled to a datalogger for recording measurements acquired by the sensors, for recording accumulated time, and the like.
2o As shown by Figure 2, each UDC according to the preferred embodiment of the invention accommodates up to eight different types of sensors. A UDC
includes the following sensors:
m 1. A carbon monoxide sensor for measuring the concentration of carbon monoxide gas of air. The sensor should be capable of providing accurate concentration measurements up to 1000 parts per million (PPM).
s 2. A carbon dioxide sensor for measuring the concentration of carbon dioxide gas. The sensor should be capable of providing accurate concentration measurements up to 10,000 PPM. A suitable carbon dioxide sensor is manufactured by Texas Instruments (model no.
to TI-4GS). Because of the relatively large physical size of the carbon dioxide sensor in comparison with the dimensions of the UDC, the sensor monoxide may be mounted outside the UDC housing.
3. A combustible gas sensor capable of measuring concentration of Is combustible gases including natural gas, propane, and gasoline vapours. A suitable combustible gas sensor is manufactured by Otron Systems Co. Ltd. of Korea (part no. SGS-801 ).
4. A smoke sensor for measuring particulate based on infrared 2o backscatter.
5. An electronic thermometer for providing ambient temperature measurements from -20 to 50 degrees Celsius.

6. An sensor for measuring the ambient relative humidity. A suitable sensor should accurately measure relative humidity from 10 to 95%
RH (non condensing).
s

7. A sensor for measuring concentration of oxygen gas.

8. An electronic barometer for measuring barometric pressure.
to Other types of sensors which may be possibly include an accelerometer, and a voltage meter for measuring the power supply voltage. In essence, however, the UDC can accommodate any suitable sensor which measures an environmental condition and provides a electronic signal, indicative of the measurement to the microprocessor.
is Depending on the sensor type, it is possible some sensors need to be coupled to operational amplifiers (National Semiconductors LM2902M) to provide a suitable signal to the microprocessor. Furthermore, because some sensors provide an analogue signals received from the sensors must be converted to a 2o digital signal at the microprocessor. According to the preferred embodiment of the invention a resistance/ capacitor network is used although any suitable analogue to digital converter may be used.

In particular, according to the preferred embodiment of the invention, the microprocessor samples data from each sensor once every second. Of course the sample rate may be adjusted according to any criterion.
s According to the preferred embodiment of the invention, each UDC
includes a datalogger. Specifically, each UDC includes an electronically erasable programmable read only memory (EEPROM) for recording sensor measurement data acquired by the microprocessor. Each datalogger records up to 256 kilobits of data before overwriting old data with new data. Sensor Io measurement data is recorded by the datalogger once every hour or as necessary along with the associated clocktime with which the measurement data is collected by the microprocessor. The EEPROM also records microprocessor RAM data to aid in the troubleshooting of a UDC device.
Is According to the preferred embodiment of the invention, each UDC
includes a digital readout comprising three seven segment LED displays. The display is used to indicate the magnitude of sensor measurements acquired by the microprocessor.
2o In response to magnitudes of the measurement acquired from the environmental sensors by the microprocessor, each UDC may activate warning lights (LED's), warning buzzers, gas shutoff valves, operate stepper motors, air intakes, exhaust fans, and control dampers to make efficient adjustments. More particularly, the microprocessor compares sensor measurements against certain predetermined criteria. Some criteria are time dependent and some criteria may be dependent upon data from more than one sensor type. Once these criteria are met, the microprocessor emits an appropriate signal to regulate an actuator.
s For example, the microprocessor may acquire a sample from a natural gas UDC once every five seconds. Once this measurement is determined to be greater than a tolerable threshold, the microprocessor emits a signal to activate an electronic gas shutoff valve.
According to the preferred embodiment of the invention, each UDC
includes four transistors for actively controlling up to four environmental conditions. That is, each UDC may activate or otherwise control any electronically activated environmental control.
is While most actuators are directly connected to the UDC from which they are controlled, according to the preferred embodiment of the invention, one conductor of the eight conductor RJ45 cabling is reserved for relaying a signal to activate an electronically activated gas shut off valve. Suitable electronically operated gas shutoff valves are manufactured by Anello in Italy.
2i A shown by Figure 3, according to the preferred embodiment of the invention, the UDCs are connected in series establishing an RS232 Local Area Network. Furthermore, every UDC operates on synchronous time.
s According to the preferred embodiment of the invention, both power and data are relayed between two neighbouring UDCs along the series by means of a removably connectable CSA approved RJ45 cable comprising eight conductors. In particular, each UDC includes an RJ45 jack for receiving a RJ45 plug of an RJ45 cable for relaying power and data with an upstream UDC, and to another RJ45 jack for receiving a RJ45 plug of an RJ45 cable for relaying power and data with a downstream UDC. RJ45 cables, plugs and jacks are modular, and readily engage and disengage, thereby facilitating the modification of the system by the addition, removal and the substitution of UDCs.
Is More particularly, the RJ45 connectors comprise eight conductors.
According to the preferred embodiment of the invention, two conductors are dedicated for delivering a power supply, one conductor is dedicated for relaying a signal to a gas valve, one conductor is dedicated for receiving RS232, one conductor is dedicated for transmitting RS232, and the remaining three 2o conductors are grounds.
Two conductors of an eight conductor RJ45 cable are used for delivering two power supplies to the first (most downstream) UDC in a connected series of UDCs. Power is delivered to the remaining UDCs by relaying the two 12 volt power supply as discussed below.
A series of up to approximately 20 UDCs may be powered by a single s power supply without significant drop to the power supplied to the most upstream UDCs. More UDCs may be connected to the series if the power supply is reinforced after about 20 UDCs. Furthermore, while the ANSI standards recommend RS232 communication be limited to 10 feet or less, under proper signal conditioning and wiring, the distance between the UDCs can be over io about a hundred feet without boosting the RS232 signal. Furthermore, each UDC includes an RS232 booster (Harris HIN202CB) for correcting the signal received from a neighbouring UDC. Thus while the series of UDCs are connected together linearly, the distribution of UDCs in a building may take many other forms, as shown by the "T" configuration of Figure 9. The irregular network ~s connections of UDCs in the "T" network shown in Figure 9 is necessary to limit the distances between UDCs.
Even under controlled environments, some sensors take several minutes to "warm-up" before providing reliable measurement data. During this initial 20 "warm-up", an integrated circuit (Claristat CC9318S) is used to automatically adjust and calibrate sensor measurements. Furthermore, once all sensors of a UDC have been successfully calibrated, the clocktime with which the UDC has completed the start-up process is recorded and transmitted to all UDCs upstream. As such, the first (most downstream) UDCs will never receive a completion signal from any other UDC; UDCs which do not receive any completion signal by default designate themselves as the first UDC of the series.
s As shown by Figure 4, when the first UDC has been successfully calibrated, the second UDC should receive a completion signal transmitted by the first UDC; a UDC which receives only one completion signal designates itself as the second UDC along the series. Furthermore once both the first and second UDCs have been successfully calibrated, the third UDC in the series to should receive two completion signals, one signal from each of the first two UDCs; a UDC which receives two completion signals shall designate itself as the third UDC along the series. In this way, after all UDCs in the series complete the startup process and the system reaches a state of equilibrium, each UDC along the series appropriately designates itself an address based on the number of Is completion signals received by downstream UDCs. Every minute, the each UDC
retransmits its completion signal to the upstream UDCs along the series. Of course, the aforementioned self-configuration technique assumes no two UDCs transmit a completion signal at exactly the same clock time; this situation is deemed highly improbable, and in any event, may be correct simply by resetting 2o the system.
As shown in Figure 8, in addition to bi-directional communication among the UDCs, the first UDC in the series (that is, the most downstream UDC) includes a DB-9 serial connector port for transferring data with a modem, and consequently, over a telecommunication network to a remote computer system.
Communication between a remote monitoring computer and a local area s network of UDCs (consisting of a series of UDCs) is important for a number of reasons. First, a remote computer facilitates the commissioning of a newly installed network of UDCs. Second, a remote computer facilitates the troubleshooting of an existing series of UDC. Third, a remote computer provides long-term monitoring and trending of a building's air quality. Fourth, a remote ~o computer enhances the optimization of energy entering a building by providing regular, customized operating instructions to UDCs. In effect, remote computer monitoring helps to reduce false alarms, reduces service costs, and increases the overall efficiency and effectiveness of the system. Furthermore, a single, centralized monitoring computer may be used to monitor multiple regionally is distributed UDC networks by monitoring a series of UDC networks sequentially.
A suitable programmable modem is manufactured by US Robotics (Model No. 0701 ). According to the preferred embodiment of the invention, it is necessary to configure the modem in several ways in order to provide an 2o effective communication gateway between the remote computer and the series of UDCs. A programmable modem can be configured by means of AT
commands, dip switches, and in other ways which will be apparent to those skilled in the art. According to the preferred embodiment of the invention, the US
Robotics 56K modem should be configured as follows:
(a) The modem is configured to operate at 9600 baud. That is, both the s maximum and minimum rates of the modem are set to 9600 baud. In general, however, the modem's rate needs only be set to some rate which is compatible with the communication rate among the UDCs. As the rate of communication among the UDCs is dependent upon the internal software UART incorporated in the microprocessor, the modem's rate is Io likewise dependent upon the internal software UART of the UDCs. While the 9600 baud rate may appear to be relatively slow, this rate has proven to be an effective compromise between data accuracy, and programming flexibility.
(b) The modem should not echo commands. That is, it is not desirable to ~s echo commands received by a UDC back up the series of UDC. While some data verification assurances may be sacrificed, the relatively slow speeds of data communication and supplemental redundancy checks provide a good degree of data accuracy.
(c) The modem should be configured to answer incoming calls automatically.
20 (d) The modem should be configured such that the data terminal ready function is non-operative.
(e) The modem should be configured such the carrier detect function is normal.

(f) The modem should be configured to load user configuration setting upon start-up rather and the factory default configuration.
According to one embodiment of the invention, the modem is powered by s an ordinary 110 Volt AC power supply. It is also contemplated, however, that the modem may be powered by means of 12 Volts DC received through the DB9 connector from the upstream series of UDCs.
According to the preferred embodiment of the invention, the modem is to connected to the telephone network, although in general is possible to connect the modem to any type of telecommunication network, whether private or public, wired or wireless.
The communication hardware and software used by the remote computer is should also be considered. The rate of communication used by the remote computer should be compatible with the rate of communication within the UDC
network. That is, in accordance with the preferred embodiment of the invention, the communication hardware of the remote computer should be set at 9600 baud. Along with compatible communication hardware, some type of application 2o software is necessary to perform various communication operations required by the remote computer. ProComm Plus software by Symantec is a suitable communication package for Windows-based computers. ProComm can be programmed to perform a sequence of operations using the Aspect 2~

programming language. In particular, once compiled, an Aspect script can be used to (1 ) configure a modem, (2) dial-up a modem connected to a UDC
network, (3) commence a communication session, (4) receive data from a UDC
network, (5) send operating instructions to any UDC device in a UDC network, s (6) store or display data in real-time, and (7) terminate the communication session. It should be noted that there are several different types of communication packages available to the remote computer which can perform the above-mentioned operations, and may be readily substituted for the Semantics product.
io More particularly with respect to the Aspect script (as programmed according to the preferred embodiment of the invention), ProComm is instructed to automatically perform the following sequence of communication operations:
is First, the remote computer must refer to a monitoring schedule in order to determine which of the UDC networks should be engaged in a communication session; a sequential series of UDC networks may be engaged by the remote computer on a "round-robin" basis. The monitoring schedule of communication sessions is based upon unique intervals of time within an hour. That is, each 2o UDC network is allocated a periodic interval in which a communication session with a remote computer is permitted to take place. As shown by Figure 10, by comparing current time data with the monitoring schedule, the remote computer will determine which UDC network should be monitored. According to the 2s preferred embodiment of the invention, a remote computer will monitor a UDC
network for up to ten minutes thereby monitoring up to six different UDC
systems per hour.
s Second, the remote computer dials the appropriate modem over the telecommunication network thereby establishing a channel of communication with a UDCs network. In general, a communication session is always initiated by the remote computer; only in an emergency will a modem connected to the local area network of UDCs initiate a communication session with a remote ~o computer.
Third, once the remote computer has received a carrier signal from the modem connected to the series of UDCs, the remote computer transmits a synchronization token (hereinafter, "synch token"). A synch token consists of the is current time data -- the day of the month, the hour of the day, the minute of the hour, and the second of the minute. As shown by Figure 11, the synch token is transmitted over the communication network to the modem, and is subsequently transmitted upstream to each of the UDCs in the series. Each UDCs records the synch token, and refreshes its time-of-day clock using data supplied in the synch 2o token. Each UDC then compares the synch token with its unique network address number (as previously determined, and discussed above). A UDC's unique address number is indicative of a UDC's permissible communication interval. That is, each UDC in the series has a unique interval of the minute in which it is permitted to transmit data to the modem. Network address numbers and corresponding permissible communication intervals are recorded in a communication schedule. Thus, by referring to a communication schedule, if the current time is within the UDC's permissible communication interval, the UDC
will s communicate sensor data along the series of UDCs downstream to the modem.
According to the preferred embodiment of the invention, a UDC network is limited to sixty UDCs; each UDC is allotted its own communication interval --a unique interval of one second, once every minute. Any data transmitted downstream from a UDC to the modem is in turn transmitted from the modem, io over the telecommunications network, to the remote computer.
More particularly with regard to synch tokens, a synch token is frequently transmitted by the remote computer to the series of UDCs within a network to provide agreement of time-of-day data among every UDC in the series and is maintain a continual stream of bi-directional communication. According to the preferred embodiment of the invention, a synch token is sent about five times a minute - whenever the remote computer is not collecting data. Furthermore, if a synch token is not received by a UDC after five minutes, a UDC ceases attempting to transmit data to the downstream modem; effectively, once the 2o telecommunication channel is interrupted, the UDCs within the network are time-out. It is important that a UDC not become "locked" into the transmitting mode once a the channel of communication between the modem and the remote computer is interrupted.

Fourth, the remote computer receives data transmitted over the telecommunication network as sent by the modem connected to the UDC
network.
Fifth, as shown in Figure 12, the stream of data collected by the remote computer may be parsed into appropriate categories and displayed in a ProComm window, and presented in a MS Excel spreadsheet in accordance with Dynamic Data Exchange (DDE) protocols, for real-time analysis, trending and to supplemental datalogging.
In addition to receiving data, a remote computer may also transmit operating instructions to any of the UDCs in the UDC network. The remote computer may transmit commands to any of the UDCs in the network. Several is useful types of commands are as follows:
1. A remote computer may issue a command to reset a UDC.
2. A remote computer may temporarily remove permissions for warning services within each UDC. For example, a remote computer may disallow ?o a UDC from activating a warning buzzer. Other warning services which may be disallowed include warning lights and the three digit display. This feature is especially important while commissioning a new network of UDCs after they have been installed and while troubleshooting and existing series of UDCs should problems arise. In commissioning and troubleshooting, it is desirable that a series of UDCs are "silent" in order to give the system administrator time to analyze the sensor results and correct problems. Once problems have been corrected, the various s warning services may be reactivated.
3. A remote computer may probe contents of a UDC's datalogger.
4. A remote computer system may transmit re-calibration instructions for individual sensors in the event of sensor drift. It is possible to transmit a "zero adjust" token or a "span adjust" token to recalibrate sensor Io measurements.
Each of the foregoing commands form part of customized operating system created by means of the "poke" and "query" command; the aforementioned functions are possible by "poking" a new value into any of the Is RAM memory locations and by "querying" the contents of RAM memory locations. ProComm may be programmed to "insert" specified valued at selected memory locations of a particular UDC. According to the preferred embodiment of the invention, various redundancy checks and verifications processes are used to ensure accuracy and security of data. As such, it is possible to adjust 2o tolerance levels, activate buzzers, trigger gas shutoff valves, and alarms, modify timeout intervals, read any set of memory locations, and perform very powerful energy conservation management.

Figures 5, 6, and 7 represent various implementations of the invention.
As will be apparent to those skilled in the art in light of the foregoing disclosure, many alterations and modifications are possible in the practice of this s invention without departing from the spirit or scope thereof. For example, while the system as described in the foregoing specification relates to monitoring and controlling indoor environmental conditions, the system need not be limited to monitoring and controlling indoor environments. By encasing the electronic components of each UDC in a weather-resistant housing (except for the sensors, ~o of course), and by connecting the series of UDCs together using weather-resistant RJ45 cables, the system may readily be adapted for outdoor use as well. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims

WHAT IS CLAIMED IS:

1. For use in a system for monitoring parameters and controlling actuators comprising a connected series of detector-controllers, each detector-controller located at one of a plurality of sites throughout a building, each detector-controller comprising:
(a) a set of sensors for generating a set of signals indicative of the environmental characteristics of the site;
(b) means for storing a set of operating instructions;
(c) means for reading the set of signals generated at the site in accordance with instructions as defined within the set of operating instructions;
(d) means for controlling an actuator when the set of signals meet a predetermined criterion as defined within the set of operating instructions; and (e) means for communicating both the set of signals and the set of operating instructions with two neighbouring detector-controllers;
a system for communicating data over a communications network to a remote computer comprising:
(a) means for communicating a set of signals indicative of the environmental characteristics at any one of a plurality of sites within a building to the remote computer; and (b) means for communicating operating instructions to any one of a series of controller-detectors from the remote computer.

2. The system as defined in claim 1 wherein the parameters include the environmental conditions and characteristics of a building, and the actuators include actuators to control the environmental conditions, characteristics and energy usage of a building.

3. The system as defined in claim 2 wherein the series of detector-controllers form a local area network.

4. The system as defined in claim 3 wherein each detector-controller in the local area network is uniquely identified by a network address.

5. The system as defined in claim 4 wherein the set of operating instructions is stored digitally.

6. The system as defined in claim 5 wherein the means for reading the set of signals is regular and periodic.

7. The system as defined in claim 6 wherein the means for reading the set of signals comprises a microprocessor.

8. The system as defined in claim 2 wherein the predetermined criterion is based upon one or more sets of signals.

9. The system as defined in claim 2 wherein the predetermined criterion is based upon the current time.

10. The system as defined in claim 2 wherein the communications network is the telecommunications network.

11. The system as defined in claim 10 wherein the means for communicating a set of signals over a communications network to a remote computer comprises a modem connected to one end of the series of detector-controllers.

12. The system as defined in claim 10 wherein the means for communicating a set of operating instructions over a communication network from a remote computer comprises a modem connected to one end of the series of detector-controllers.

13. The system as defined in claim 2 wherein the means for communicating the set of signals over a communications network and the means for communicating a set of operating instructions over a communications network occur during a communication session.

14. The system as defined in claim 13 wherein a series of communication sessions are regular and periodic.

15. The system as defined in claim 14 wherein during a communication session, sequentially, each detector-controller in the series of detector controllers is granted a unique priority communication interval in which to communicate a plurality of sets of signals through the series of detectors, over the communication network to the remote computer.

16. For use in a system for monitoring parameters and controlling actuators comprising a connected series of detector-controllers, each detector-controller located at one of a plurality of sites throughout a building, each detector-controller comprising:

(d) a set of sensors for generating a set of signals indicative of the environmental characteristics of the site;
(e) means for storing a set of operating instructions;
(f) means for reading the set of signals generated at the site in accordance with instructions as defined within the set of operating instructions;
(d) means for controlling an actuator when the set of signals meet a predetermined criterion as defined within the set of operating instructions; and (e) means for communicating both the set of signals and the set of operating instructions with two neighbouring detector-controllers;
a method for communicating data over a communications network to a remote computer comprising the steps of:
(c) communicating a set of signals indicative of the environmental characteristics at any one of a plurality of sites within a building to the remote computer; and (d) communicating operating instructions to any one of a series of controller-detectors from the remote computer.

17. The method as defined in claim 16 wherein the parameters include the environmental conditions and characteristics of a building, and the actuators include actuators to control the environmental conditions, characteristics and energy usage of a building.

18. The method as defined in claim 17 wherein the series of detector-controllers form a local area network.

19. The method as defined in claim 18 wherein each detector-controller in the local area network is uniquely identified by a network address.

20. The method as defined in claim 19 wherein the predetermined criterion is based upon one or more sets of signals.

21. The method as defined in claim 19 wherein the predetermined criterion is based upon the current time.

22. The system as defined in claim 17 wherein the steps of communicating the set of signals over a communications network and communicating a set of operating instructions over a communications network occur during a communication session.

23. The system as defined in claim 22 wherein a series of communication sessions are regular and periodic.

24. The method as defined in claim 23 wherein during a communication session, sequentially, each detector-controller in the series of detector controllers is granted a unique priority communication interval in which to communicate a plurality of sets of signals through the series of detectors, over the communication network to the remote computer.