Programmable temperature sensor for security system

IS 2 174 598 T3

DESCRIPTION

Programmable temperature sensor for security system.

Technical sector of the invention

The present invention relates to a programmable temperature sensor for a device as part of a security system, as well as to the device incorporating such a temperature sensor. In a preferred embodiment, the programmable temperature sensor is capable of having multiple set points, each individually programmable in effect.

Background of the invention

Temperature sensors are used in a wide variety of applications where it is necessary to monitor the temperature in a space. For example, cold rooms are used for the preservation of perishable items, in which the items must be kept within a specific range of temperatures to prevent deterioration of the items. In such areas, temperature sensors are used to monitor the temperature inside the area to ensure that the temperature does not rise to a point where the items are at risk of spoiling. In such applications, a separate temperature sensor is connected to an alarm system to provide a warning signal if the temperature rises above a particular limit. This limit is generally set at the factory when the unit is manufactured and represents a temperature sensor set point for the temperature sensor. If the temperature detected by the temperature sensor exceeds the temperature set point established in the manufacture of the unit, the alarm system indicates the alarm. In applications where it is necessary to monitor mine for a set point, such as an upper and lower limit, a second independent temperature sensor is typically used with its own individual set point other than the first sensor set point. These sensor set points are generally set during unit manufacture and are not field programmable.

In addition to cold rooms, there are many other applications in which temperature sensors are used. For example, storage areas where products are stored that must be prevented from freezing need to have the temperature monitored to ensure that it does not drop below a level at which the products can freeze. Another example would be greenhouses used for the production of commercial crops, particularly high value crops such as flowers and exoitic plants, as well as certain herbs. In such applications it is critical to keep the temperature in the greenhouse within an acceptable growth range, while ensuring that the temperature has not reached a level that could cause permanent damage to the crops, either because the temperature falls below a level where crops are damaged, already because the temperature rises to a level where crops are damaged.

Currently, in such circumstances, when it is desired to monitor a variety of set points, the requirement for independent temperature sensors is necessary for each of the set points to be monitored. Furthermore, once the temperature set points have been established in the unit, it is extremely difficult to modify or vary these temperature set points, often requiring the unit to be returned to the factory to change the temperature set points.

Temperature sensors are also used in a number of different applications, specifically for monitoring environments where computer equipment is installed. One such monitoring system is described in US Patent 5,566,339, issued October 15, 1996 to Fox Network Systems Inc. The monitoring apparatus described in this patent allows computers to continue to operate in the event of a power failure including an uninterruptible power supply system and a number of monitoring systems to monitor the operation of the computer network as well as for the audition of a system of several alarms. The unit also includes a telephony interface to automatically contact a person in the event of a problem with the system. Included in the monitoring unit is a temperature sensor to monitor the temperature of the space in which the monitoring unit is located.

DE-A-4,020,395 describes a temperature sensor which has several programmable alarm set points and which is coupled to an alarm system, see col. 1, lines 55 to 61; cabbage. 2, lines 37 to 42.

Alarm systems that include a temperature sensor function require that the temperature sensor be an individual device, independent and separate from the other devices in the alarm system. Providing the temperature sensor as a standalone device increases the cost of installing the alarm system, both in terms of the cost of the device and the cost of installing the alarm system, since the temperature sensor requires its own wiring and interface with the alarm control panel. If the temperature sensor function could be part of another alarm system, the complexity and cost of the alarm system could be reduced.

There therefore remains a need for a means for providing a device for an alarm system with a temperature sensor function, in which the temperature sensor set point is easily programmable. There is also a need for an alarm system that allows the monitoring of multiple temperature set points and in which the set points can be easily programmed depending on the situation or position in which the alarm system is located.

Summary of the invention

The invention is defined in the appended claims.

IS 2 174 598 T3

The present invention provides, in one aspect, a programmable temperature sensor for a device as part of a security or alarm system. The programmable temperature sensor is capable of having multiple programmed set points, each set point being individually programmable in terms of level and effect.

In another aspect of the invention, a keypad controller is provided for use in an alarm system. The keyboard controller comprises input means for interfacing a user with the keyboard controller and an alarm system to which the keyboard controller is connected, output means for providing one or more visual and audible feedback to a user about the status of the system, an interface means for communicating with an alarm control panel of an alarm system, processing means to process the inputs from the input means or an alarm control panel and cause the output means to be provided with the appropriate information, and a programmable temperature sensor to monitor the temperature in the space in the room. that the keyboard controller must be located, the temperature sensor being provided with at least one programmable alarm set point in terms of its level.

Brief description of the drawings

The preferred embodiments of the present invention are illustrated in the accompanying drawings, in which:

Figure 1 is a block diagram of an alarm system of the present invention incorporating a keypad with a programmable temperature sensor that is part of the keypad;

Figure 2 is a graph illustrating the detection of an increase and recovery in temperature in the programmable sensor of the keyboard of Figure 1 as a function of time and the associated events that occur; and Figure 3 is a flow chart showing the flow of the temperature evaluation program in a monitored area using a device according to Figure 1.

Detailed description of preferred embodiments

Figure 1 illustrates a block diagram of an alarm or security system incorporating a device having a programmable temperature sensor in accordance with a preferred embodiment of the present invention. The alarm system comprises an alarm control panel 10 that controls the operation of the entire system. A number of detection devices or sensors 12, used to monitor a protection zone or area, are connected to the control panel in a typical way. The sensors 12 can be any of the commonly used sensors such as motion detectors, door contacts, glass break detectors, shock sensors, fire detectors, water detectors, etc. The sensors 12 in Figure 1 are shown wired with the control panel 10, although wireless technology is in common use and any of the sensors 12 could use wireless communications between the detection devices 12 and the control panel 10. The alarm system may be able to report to a remote monitoring station 14, using any of the commonly used communication methods such as the use of a telephone dialer that sends messages to the remote monitoring station 14 using telephone systems. local 16. In some situations, the connection between the control panel 10 and the remote monitoring position 14 may also be wireless, using cell phone technology or other means of wireless communication. The system may also employ other communications arrangements such as two-way cable systems. A keyboard controller 20 is also connected to the control panel 10 to act as a user interface with the alarm system, to program the system and control the operation of the system, and to display the status of the system and its different components.

The keypad controller 20 of the alarm system illustrated in Figure 1 was provided with a system I / O interface (I / O SYSTEM) 22 that interfaces with the alarm control panel 10. The I / O SYSTEM 22 can also be used as an interface with other devices, such as auxiliary heating or cooling equipment, either directly using the I / O SYSTEM 22, or through the alarm panel 10 which, as illustrated in Figure 1, it interfaces with a climate control system 18. The keyboard controller 10 is provided with input means 24 for user interface with the alarm system. The input means 24 may be a simple numeric keypad, or an alphanumeric keyboard, or may be provided through a graphical interface provided as part of a touchscreen monitor of the keyboard controller 20. The keyboard controller 20 is also provided with output means 26 that provide visual or sound feedback to the user and to provide information about the status of the system and its different components. The output means 26 may provide visual or audible feedback or may provide a combination of both types of feedback. For visual feedback, the output means 26 may include a single LED or dual-line LCD monitor, or it may be a larger LCD monitor capable of displaying graphical messages in addition to alphanumeric messages. If such a larger LCD monitor is provided, it may also serve as input means 24 with touchscreen capability.

The input means 24 and the output means 26 of the keyboard controller 20 are connected to a processing means 28 that processes the inputs from the input means 24, passes the data to the alarm control panel 10 and receives the data from the same through the I / O SYSTEM 22 defined above, and allow feedback from the monitor to the user and the status of the system to the output means 26. The keyboard controller 20 may also be provided with a non-volatile memory 30 for soul3

ES 2 174 598 T3 storage of instructions for the processing means 28 as well as for storing different parameters for the operation of the system. The keyboard controller 20 is also provided with a temperature sensor 32 which, according to the present invention, has at least one programmable set point for its level. Preferably, as described later, temperature sensor 32 is programmable to have multiple set points. The temperature sensor 32 is provided with temperature sensor means that provide an output that varies in proportion to the captured temperature. The temperature sensor is also provided with an interface or signal conditioning means to allow the processing means 28 to receive a signal indicative of the temperature, compare this signal with one or more set points and take the appropriate action. The temperature sensing means can use any of the currently available technologies or any technology that is developed in the future. For example, the temperature sensing means may be a resistive sensor whose resistance varies with temperature. Examples of resistive sensors include a Resistance Temperature Detector using platinum film or filament or a thermistor. The temperature sensing element can also be a thermocouple whose output voltage varies with temperature. The temperature sensing element can also be a temperature sensing integrated circuit whose output varies with temperature. The output of the integrated circuit can be voltage or current or it can be provided with an internal comparator that outputs a digital signal. Examples of such temperature sensor ICs are those manufactured by National Semiconductors such as the LM35 and LM45 Celsius sensors that provide a voltage output, the LM134, LM234 and LM334 current output temperature sensors, and the LM56 low power thermostat. which provides a comparator output. For temperature sensing elements that provide a resistance, voltage or current output, signal conditioning will be required to provide an appropriate signal for the processing means. Such signal conditioning means may include an A / D converter to convert the output voltage or current into a digital word that can be used by the processing means to compare with the threshold value, or a comparator to compare the output with the reference levels representing the expected values ​​at the threshold set points. The output from the signal conditioning means will be supplied to the processing means and may also require an interface, depending on the nature of the output.

Another integrated circuit temperature sensor is the LM75 Digital Temperature Sensor, which originally incorporates an A / D converter that converts the output of the temperature sensing element into a digital word and stores the digital word in an addressable register. This is the preferred temperature sensor to be used in the present invention, since the captured temperature has already been converted into a digital word and stored in an addressable register. Another advantage of the LM75 Temperature Sensor is that it uses an I bus²C, so it is easy to interface to the processing means 28. The processing means 28 will interrogate the LM75 temperature sensor 32 by reading the value stored in the temperature register. This value will be compared to the value for the temperature set point to determine if the temperature exceeds the set point temperature as described later.

The set-up of the control system illustrated in Figure 1 is of particular use in installations where it is desirable or necessary to monitor the temperature in the space in which the keyboard controller is located. Examples of such locations may include greenhouses, cold rooms, or other such facilities.

Figure 2 illustrates the concept of multiple set points using a device such as the keypad controller 20 shown in Figure 1 with a temperature sensor with three thresholds or set points to which the alarm system will respond. The alarm system in Figure 2 has been programmed for use in a cold zone so that the alarm condition being monitored is a rise in temperature. In prior art systems, a single set point would have been provided and when the temperature had exceeded the threshold, an alarm condition would have been indicated, which could also be transmitted to a remote monitoring station, depending on the case. In the embodiment of the invention illustrated in Figure 2, the ALARM 1 threshold may, for example, indicate a local trouble condition, the ALARM 2 threshold may indicate an alarm and initiate an alarm transmission to a parking station. remote monitoring and ALARM 3 threshold can activate a safety cooling system. As the temperature in the monitored area increases, the ALARM 1 threshold will be exceeded and the alarm system will announce a local trouble condition to alert the user of a potential failure of the climate control system. If no corrective action is taken, and the temperature continues to rise until it exceeds the ALARM 2 threshold, the alarm system will report the overheating status to a remote monitoring station, indicating that a call to technical assistance is required. . If the necessary repairs are not made before the temperature exceeds the ALARM 3 threshold, the security system employing a preconfigured I / O such as the one shown in Figure 1 will activate a climate control system from safety or take other actions to limit the severity of the damage caused by the overheating state.

When the temperature falls below the ALARM 3 threshold again, no action is taken. The temperature should drop by

ES 2 174 598 T3 below the RESET 3 threshold before the security system deactivates or the other action associated with the ALARM 3 threshold is deactivated or reversed. This hysteresis prevents multiple unwanted ALARM and RESET states from occurring if the temperature fluctuates around the threshold point. The system responds in a similar way when the temperature falls below the RESET and RESET 1 thresholds, sending an overheating reset signal to the monitoring station and resetting the trouble status due to excess temperature, respectively.

Figure 3 illustrates a flow chart for one embodiment of a program to be used in a system having multiple set points as illustrated in Figures 1 and 2 in order to evaluate the temperature in a monitored zone. In the system, the temperature sensor 32 would be periodically interrogated by the processing means 28 about the current temperature. This routine will be executed every time a new temperature is read. In the flow chart of Figure 3, ALARM 1, ALARM 2 and ALARM 3 represent flags (single bit volatile storage locations, preferably formed by part of the processing means 28). These flags are used to track the current status of each of the alarm levels. If the flag is set, the associated alarm is active, and if the flag is steel or not set, the associated alarm is not active.

Once read, the temperature is compared with the ALARM 3 and RESET 3 thresholds to determine if it is above, below or within this range. If the temperature read was above the ALARM 3 threshold and ALARM 3 is not currently active, the action assigned to the ALARM 3 event is activated and the ALARM 3 flag is set. If the read temperature was below the RESET 3 threshold and ALARM 3 is currently activated, the action assigned to the RESET event is processed and the ALARM 3 flag is reset. Once the appropriate action has been carried out or if any of the above conditions are not satisfied, the same tests are performed for the ALARM 2 and ALARM 1 ranges. After all the tests and actions are completed, the program control of the processing means 28 returns to the main routine.

A preferred embodiment of the present invention has just been described with respect to an alarm system for use in a cold storage area, in which the keyboard, which is located within the area to be monitored, was provided with a programmable temperature sensor. to monitor the temperature of the area. The temperature sensor communicates with the keyboard controller processing means and the alarm control panel to provide the processing means and the control panel with an indication of the temperature in the space that is monitored at any given time. The processing means and the control panel compare the temperature indication of the temperature sensor with one or more thresholds programmed in the keyboard controller or the control panel and the system performs various actions as described above, based on the result of the comparison.

The alarm system temperature thresholds are fully programmable and can be easily adjusted based on the requirements of the system and the location to be monitored.

In addition to the keyboard controller, other devices than those used in alarm and security systems can also be provided with programmable temperature sensors. For example, a smoke detector could be provided in conjunction with the temperature sensor, to provide additional smoke detector functionality. The temperature sensor may have thresholds programmed to allow it to function as a heating or rate-of-rise detector. The temperature sensor could also be programmed so that one of the actions to be taken could be to adjust the sensitivity of the detector for detecting fire conditions. IF the temperature sensor finds that the temperature in the space being monitored is increasing, albeit at a slower rate than the rate set for the rate of increase function, one of the actions taken could be to supply a local or remote trouble status. . Another potential action could be to adjust the sensitivity of the rate of rise or heat detector to provide a quick warning of a potential fire condition.

The programmable temperature sensor of the present invention may also be provided with means for determining the time of day as well as the day of the year. By providing an indication to the temperature sensor regarding the time of day as well as the day of the year, additional functionality can be provided to the alarm system. For example, when the alarm system is located in a space that is normally only occupied on weekdays, the system could be programmed for different functions depending on the day and time. During the time the space is occupied, the system can be programmed to primarily monitor temperature increases above set points and would provide local trouble indication at the first threshold. At night, when the temperature in space is expected to drop naturally, primary monitoring may use a lower ALARM threshold than during the day. In addition, since it is to be expected that no person is present in the space, when the first threshold is exceeded, the system can, in addition to providing a local trouble indication, be programmed to provide a trouble condition indication to a monitoring station. remote, in order to be able to act from the first moment.

By providing the system with indication of the day of the year, the system can also be programmed to execute different actions on days when the space is expected to be unoccupied, such as on weekends and holidays. The system can also be programmed to consider seasonal changes based on the

ES 2 174 598 T3 indication of the day of the year. For example, an occupied space is extremely unlikely to risk reaching freezing temperatures during the summer months, so the system's primary thresholds in summer would be to monitor temperature increases. On the contrary, in winter, when the risk of freezing is higher, primary monitoring would be carried out for temperature drops.

Although the system has been described with a primary monitoring threshold that can be modified based on the time of day and the day of the year, the system can be programmed to continue to monitor temperature changes in both directions. The time of day or the day of the year can be used as a parameter to vary the action to be taken in response to the system detecting that any particular ALARM threshold has been exceeded.

The programmable temperature sensor of the present invention can also be adapted to respond to the alarm state of the system. In many situations, the alarm system can function as a security system that would arm itself when the premises are not occupied. When the alarm system is armed, the action performed with the detection that a temperature ALARM threshold has been exceeded may differ from that performed when the system is not armed. When the system is armed, it would be expected that no one is occupying the premises and that responses to exceeding the threshold of a first ALARM could include notification of a remote monitoring service or other remote location such as a business owner. When the system is disarmed, it would be expected that someone is occupying the space and that a local notification will be given when the threshold of the first ALARM is exceeded.

The preferred embodiment of the above-described system having a keyboard with the temperature sensor of the present invention is adaptable for many different applications. The illustrated embodiment is for use in a location where temperature rise is monitored. The system is equally adaptable for monitoring the drop in temperature such as in a space that needs to be heated or for situations in which both a drop and an increase in temperature must be monitored, such as in a space where the temperature it must be kept within a specific range. If it is desired to monitor a drop in temperature, either itself or in conjunction with an increase in temperature, the ALARM thresholds should be set based on the desired temperature at which the different alarm events should be executed. Individual RESET thresholds would be set a few degrees above their respective ALARM thresholds to provide hysteresis. The operation of the system would be similar to the described embodiment, first comparing the monitored temperature with the extreme ALARM and RESET thresholds, followed by the less extreme ALARM and RESET thresholds. The system could be programmed to recheck against the extreme low or high thresholds, followed by the other extreme low or high threshold. The system could then be checked against each pair of less extreme thresholds, again against one of the high or low thresholds and then against the other. This would continue until the monitored temperature has been compared with all the thresholds, at which time the time control would return to the main routine, or until an alarm condition was detected, at which time the action associated with the alarm condition would be executed.

The illustrated preferred embodiment has the control programs for the verification of the temperature thresholds resident in the keypad controller. In this embodiment, the processing means has the necessary programming to compare the monitored condition with the thresholds in the manner previously described. If a first alarm event is determined from this comparison, the keypad controller processing means passes an instruction to the alarm control panel to initiate the appropriate alarm notification. If the processing means does not detect any alarm events, control returns to the main routine for the processing means described above.

Under some conditions, some or all of these control programs could be resident in the alarm control unit. The keyboard could monitor the temperature and perform the comparison verification with the thresholds and pass the test result to the control panel, where the results would be processed to execute the opportune action. Alternatively, the keyboard control processing means could monitor the temperature of the temperature sensor and pass the level of the monitored temperature to the control panel, where all the treatments and checks of the temperature against the thresholds would be carried out.

The device for an alarm system of the present invention that includes the programmable temperature sensor allows to design low-cost security and alarm systems with flexibility regarding the monitoring of temperature in a space and the adoption of appropriate actions depending on the temperature in space. The programmable temperature sensor set point is easily adjusted based on the application and desired alarm point by modifying the set point value stored in memory to which the temperature in space is compared. Furthermore, the action to be executed by the alarm system in response to the temperature exceeding the set point value is easily programmable by modifying the routines stored in memory.

The programmable temperature sensor of the preferred embodiment of the present invention with multiple programmable set points allows alarm and security systems to have improved flexibility for temperature monitoring and appropriate action. For the provision of multiple

ES 2 174 598 T3 set points, problems in temperature control can be detected earlier than in systems that use a single set point, and different actions can be assigned to each threshold level. Individual set points are programmable, allowing the system to be easily adapted to many different locations and applications. By providing multiple set points, both temperature excesses and defects can also be monitored.

Although various preferred embodiments of the present invention have been described in detail herein, it will be appreciated by those skilled in the art that it may be subject to variations without departing from the scope of the appended claims.