Abstract: A powered wall plate with a plug-in module having an electrical plug and an module cover. The electrical plug has at least two electrical prongs that are configured to removably mate with an electrical receptacle. The module cover is located adjacent to the electrical plug and has a surround configured to extend around a portion of the perimeter of the wall plate, an LED light located along a bottom edge of the module cover, a USB port exposed on a surface of the module cover, and a circuit contained within the module cover and configured to supply power to the USB port and the LED light when power is supplied to the electrical prongs. The wall plate has a first mounting screw aperture and the plug-in module has a second mounting screw aperture that receive a mounting screw, attaching the plug-in module to the wall plate and the electrical device.

Abstract: A parking space monitoring system, with multiple microprocessors for handling various parking space management conditions, including at least one of the following conditions: (1) Space Occupancy (vehicle detection); (2) Parking Meter Status; (3) Display of Parking Policy to Motorists; (3) Motorist User Interactions; (4) Maintenance User Interactions; (5) Radio Communications with a Central management system and Network; and (6) Coordination of the operation between various ones of the microprocessors.

Abstract: A harvester grain bin monitoring system is disclosed. The system includes a sensor that monitors the perimeter of the bin proximate to the top rim to provide a warning to an operator when the grain level reaches approaches the bin rim. The sensor may be optical or mechanical.

Abstract: An article destruction device includes an electric motor driving at least one moving component. An indication panel includes at least three visual indicators situated in sequence. Each visual indicator is associated with a stage of an approaching overload (motor cool down) condition. A first visual indicator lights when the motor or corresponding sensor temperature is below a first threshold, i.e., when the device is first powered on. A second indicator lights when the temperature exceeds the first threshold and is below at least a second threshold, i.e., the temperature is approaching a fault condition. A last visual indicator lights when the temperature exceeds the first and the at least second thresholds, i.e., the fault condition is met. A thermistor on the motor energizes (self-heats) with the motor. A thermostatic switch controls current flow through windings of the motor depending on measured temperatures meeting operating and equilibrium temperature thresholds.

Abstract: A radio-based heat detection pellet is provided. The pellet includes a thermal switch configured to provide a detection signal when exposed to a temperature greater than a predetermined threshold temperature. The pellet further includes a transmitter circuit connected to the thermal switch and configured to transmit an alarm signal to a remote location in response to receiving the detection signal.

Abstract: An interface device includes an elongated sensor strap having a secured end and an unsecured end opposite to the secured end. The unsecured end of the sensor strap represents a first sensor half, and a second sensor half is adapted to receive the first sensor half/unsecured end to form a sensor link between the two sensor halves. A deployment sensor switch provides an input to a monitoring device for an alarm system. The deployment sensor switch is adapted to reside in an armed state when the first and second sensor halves form a sensor link, but change to an alarm state when the first sensor half and second sensor half are separated to break the sensor link. The sensor strap is sufficiently long to produce a closed loop around a firearm or other object to in a monitored position when the first and second sensor halves are placed together to form the sensor link.

Abstract: A safety apparatus has a configurable safety controller (10) and a configuration means, wherein the safety controller (10) has at least one input (18) for the connection of a sensor (20a-c), at least one output (22) for the connection of an actuator (24a-b), and a control unit (14) configured to carry out a control program which generates a control signal at the outputs (22) in a dependence on input signals at the inputs (18) by means of logic rules. The logic rules are settable by means of the configuration means. A number code representing the logic rules can be generated in the configuration means, and the safety controller (10) includes an interface (30) for the input of the number code. The control unit (14) is configured to carry out a control program with the logic rules represented by the number code.

Abstract: Described are a method and a sensor aware network for dynamic processing of sensor data. Network context data are inserted into data packets from sensors or local sensor networks coupled to the sensor aware network. Sensor aware nodes in the sensor aware network can read the context data and can respond by performing specific network actions. The sensor data and network context data are provided to one or more application nodes. The sensor data and network context data can be stored in a database and later searched according to the network context data. Advantageously, sensor data flows can be treated differently by the sensor aware network, the application and the user, depending on the type of sensor data and the actual data values. Thus critical responses to certain sensor data flows can be implemented more efficiently than otherwise possible using conventional network configurations.

Abstract: A load circuit disconnection detector includes: a current sensor (16) for detecting current flowing through a wire (W1) of a load circuit; and a protective device (100) for estimating temperature of the wire (W1) based on the detected current and forcibly turning off a semiconductor switch (Q1) if the estimated temperature of the wire reaches threshold temperature. The load circuit disconnection detector determines that there is a connection failure in the load circuit if a temperature increase calculated by a temperature calculation unit (24) is zero even a predetermined time (P1) after the semiconductor switch (Q1) is turned on.

Abstract: A method for teaching a switching circuit is provided. The method includes presenting a target within a sensing range of a sensor of the switching circuit for a pre-determined duration and acquiring an identification code of the target via the sensor. The method also includes storing the acquired identification code for operating the switching circuit and locking the switching circuit against learning identification codes of any other target prior to reaching an allowed number of reteaching attempts.

Abstract: A rotation-activated electronic component, preferably a RFID tag mounted on or incorporated in a support that is rotated when read, e.g. a CD or DVD. The RFID tag comprises an antenna, a rotational switch, a component, advantageously a processor, and a time usage limiter. The antenna is adapted to transform received RFID signals to electric energy that powers the component and the rotational switch is adapted to cut the circuit unless the support does not rotate at or above a certain rotational speed. The time usage limiter counts down a timer when it is powered via the rotational switch and disables the RFID tag when the timer expires. Supports equipped with the RFID tag of the invention will thus respond until the timer expires, and preferably only if they rotate sufficiently.

Abstract: A radio-based heat detection pellet is provided. The pellet includes a thermal switch configured to provide a detection signal when exposed to a temperature greater than a predetermined threshold temperature. The pellet further includes a transmitter circuit connected to the thermal switch and configured to transmit an alarm signal to a remote location in response to receiving the detection signal.

Abstract: A capacitor providing a thermal alert includes a wound film capacitor for carrying a large current when coupled to an AC generator. The wound film capacitor includes a hollow core extending from one end to another end of the capacitor. Also included are an in-line thermal switch, which is disposed in the hollow core for sensing a predetermined temperature; and a light indicator, which is coupled to the thermal switch. A single housing is integrally formed from an upper cover and a lower cover for housing the capacitor, the thermal switch and the light indicator. The upper cover of the housing is formed from translucent material. The thermal switch is configured to disconnect the wound film capacitor from the AC generator upon reaching the predetermined temperature, and activate the light indicator to emit a light. The upper cover is effective in transmitting the light from inside the housing to outside of the housing.

Abstract: A programmable graphical display switch is described herein that provides users with a way of controlling other devices and for customizing how that control is initiated and communicated to a user.

Abstract: An emergency override system includes first and second communication interfaces, a sensor, and a processor. The first communication interface is connected to the second communication interface by a communication line. The sensor is disposed along the communication line and is configured to output signals in response to sensing network data being transmitted on the communication line. The switch is disposed along the communication line and has an open configuration and a closed configuration. The processor is coupled to the switch and the sensor and is configured to control the opening and closing of the switch in response to the signals transmitted by the sensor. The processor provides device control data to the network device over the communication line when the switch is open. The network control data commands the network device to perform a predetermined function in response to a lack of network data being transmitted on the communication line.

Abstract: A fire detection system comprises a detection unit (2A) able to measure an electrical quantity between a first (BOA) and a second (B1A) terminal, and a first detector (11A) connected to the first and second terminals (BOA, B1A) and able to form a first value of the electrical quantity in a determined state of the first detector, for example in the event of the detecting of a fire in a first zone (Z). A second detector (12A) connected to the first and second terminals (BOA, B1A) is able to form a second value of the electrical quantity in said determined state, that is to say for example in the event of the detecting of a fire in a second zone, and a third value of the electrical quantity in another state different from the determined state, that is to say for example during normal operation. The first value and the third value are different from the second value.

Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: R3 is selected from cyclopentyl and cyclohexyl; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high dual efficacies for human cathepsin S and K and are useful for the treatment of rheumatoid arthritis, osteoarthritis, chronic obstructive pulmonary disease (COPD), atherosclerosis, cardiovascular diseases which exhibit significant damage and remodeling of extracellular matrix (ECM) and chronic pain.

Abstract: A detection apparatus includes a casing, a movable member moving from a position outside the casing to a position inside the casing upon contact of a detection object, a radio communication device disposed on the movable member and configured for radio communication with a sending and receiving unit via radio waves, a shielding member for shielding the radio communication between the radio communication device and the sending and receiving unit in a state that the movable member is located within the casing, and a controller for determining the presence of the detection object by determining whether the sending and receiving unit can communicate with the radio communication device.

Abstract: A capacitor providing a thermal alert includes a wound film capacitor for carrying a large current when coupled to an AC generator. The wound film capacitor includes a hollow core extending from one end to another end of the capacitor. Also included are an in-line thermal switch, which is disposed in the hollow core for sensing a predetermined temperature; and a light indicator, which is coupled to the thermal switch. A single housing is integrally formed from an upper cover and a lower cover for housing the capacitor, the thermal switch and the light indicator. The upper cover of the housing is formed from translucent material. The thermal switch is configured to disconnect the wound film capacitor from the AC generator upon reaching the predetermined temperature, and activate the light indicator to emit a light. The upper cover is effective in transmitting the light from inside the housing to outside of the housing.

Abstract: An over temperature detector circuit for use in a switching converter including one or more power switches in accordance with an embodiment of the present application includes a silent sense generator connected to at least one power switch and operable to detect a noise level of the switch and to provide a generator output signal indicative of absence of switching noise and a comparator operable to compare a temperature sensor signal from a temperature sensor with a reference voltage to provide an alarm signal indicating an over temperature condition when the temperature sensor signal exceeds the reference voltage, wherein the alarm signal does not indicate an over temperature condition when the generator output signal does not indicate absence of switching noise.

Abstract: A low cost flame sensing system having at last one floating point. For instance, the system may have two grounds. There may be a flame sensing rod for detecting a flame which has a model circuit which appears upon the existence of the flame proximate to the sensing rod. The sensing rod may function without an explicit or dedicated excitation source connected to it. There may be diagnostics in the system for detecting leakage or shorts of the sensing rod to ground. Also, the system may have AC grounding phase detection.

Abstract: An electrical device for performing a particular function includes a system circuit for performing the function, and a dedicated power supply for providing power to the circuit. Both the system circuit and the power supply are hermetically sealed within a housing. The device within the housing is intended to be sterilized using high temperature, reaching a sterilization temperature. According to the invention, the device includes a thermal switch which is electrically connected between the system circuit and the power supply. The thermal switch is switchable between an open position wherein the system circuit is electrically isolated from the power supply and receives no power therefrom and a closed position wherein the system circuit is electrically connected to the power supply and receives power therefrom. The thermal switch switches from its closed position to its open position in response to the temperature within the housing rising to a predetermined switch-open temperature value.

Abstract: The invention relates to a device for switching at least one current includes a switching mechanism located in a switching chamber. The switching mechanism interrupts and connects a current path in an orderly fashion. Switching devices frequently have a protective function, e.g. relative to a power grid, and it is therefore desirable for supporting the protective function to identify faults and/or wear within the switching device. To this end, the switching device includes at least one temperature measuring unit that aids in detecting faults and wear within the switching device.

Abstract: An over temperature detector circuit for use in a switching converter including one or more power switches in accordance with an embodiment of the present application includes a silent sense generator connected to at least one power switch and operable to detect a noise level of the switch and to provide a generator output signal indicative of absence of switching noise and a comparator operable to compare a temperature sensor signal from a temperature sensor with a reference voltage to provide an alarm signal indicating an over temperature condition when the temperature sensor signal exceeds the reference voltage, wherein the alarm signal does not indicate an over temperature condition when the generator output signal does not indicate absence of switching noise

Abstract: Temperature sensor device that allows changes of temperature (14) to be detected, as the materials that form said device (1) are deformed, that consists of a body formed by two valves (2) and a structure (8) provided in the hollow interior (7), so that they join together with the aid of a number of bolts (5), it having been envisaged that in one of the bolts (5) and in the structure (8) electrical terminals (4) are positioned, separated a distance (12) from each other, so that when an increase in temperature (14) takes place, it causes the deformation of the components of the device (1), allowing contact of the electrical terminals on having reached the critical temperature (14), and producing the activation of a warning device (13) with the aid of a conductive medium (10)

Abstract: An apparatus for indicating detection of an onset of a high-voltage condition at an output locus of a signal converter device, the signal converter device including a switching network for switchingly controlling a potential at a circuit node coupled with the output locus in response to a control signal received from a control signal source, includes: (a) a first sensing unit coupled for sensing a parameter at the circuit node; (b) a second sensing unit coupled for sensing the control signal; and (c) a comparing device coupled with the first sensing unit and with the second sensing unit; the comparing device effecting comparison of a first signal from the first sensing unit with a second signal from the second sensing unit. The comparing device effects the detection when the first and second signals have a predetermined relationship, then the apparatus effects the indicating.

Abstract: Mechanically and reversibly activating or deactivating a radio frequency identification (RFID) data tag. An RFID tag includes an RFID chip for storing an RFID code, an antenna for communicating a radio frequency (RF) signal, and a mechanical switch coupling the RFID chip to the antenna. Closing the mechanical switch enables the RFID chip and the antenna to communicate the RFID code via the RF signal.

Abstract: An alarm device for signaling when an object reaches a specified condition. The alarm device includes a sensor for detecting the condition of the object. The device further includes a switch element which is closed when the sensor indicates the specified condition. The closed switch element triggers an alarm which will signal a person monitoring the condition that the specified condition has been reached.

Abstract: An integrated piezo-resistive sensor for determining mirror position in an optical switch. One or more piezo-resistive layers may be formed in silicon springs supporting a movable mirror in the switch. Change in resistivity of those layers due to spring deformation during mirror motion is measured and related to the mirror deflection angle. Information about the angle may be used to provide feedback to the motion actuator, which then may be operated to orient the mirror more accurately. A sensor's sensitivity may be increased by appropriately orienting the springs with respect to the crystallographic axes of the silicon.

Abstract: A motion sensitive device for causing an electronic signal to be sent to one or more output devices, comprising a printed circuit board, a battery connected to the printed circuit board, electrical circuitry connected to the printed circuit board, a motion sensitive switch connected to the printed circuit board, electrical output devices such as light emitting diodes connected to the printed circuit board and electrical circuits all providing means whereby the motion sensitive switch causes a signal to be transmitted to the output device when movement is sensed by the switch. The device is small enough to be used in wearing apparel and can provide safety vis-à-vis increased visibility for the user.

Abstract: An apparatus for determining a melt spill during Czochralski crystal growing processes, having a sensor or detector that allows the creation or cessation of a signal when the presence of melt spill is detected. This invention includes a sensor or detector that can operate in high temperature conditions without causing contamination to the crystal growth process. Any detected melt spill triggers an alarm so that potentially dangerous and costly situations may be avoided. The melt spill detector may be placed in any location advantageous to detect the melt spill, and may be incorporated into the components of the crystal growing apparatus.

Abstract: Available spaces in a system may identified using detectors in each of the spaces. The detectors may communicate the availability of a space after detecting whether or not an item is currently situated at the space. This information may be assembled and displayed using mapping software to indicate available spaces. In addition, a user may be provided with information about how to traverse through the system of spaces to locate the available space. In one embodiment of the present invention, the available spaces are parking spaces and the user is a vehicle operator having an in-car personal computer system. An in-car personal computer systems may have a display showing a map of the parking facility, indicating an available space and providing directions to reach that space.

Abstract: An electrical system is provided which includes multiple electrical loads which are powered by an AC voltage source. A synchronization circuit generates a synchronization signal which is representative of the half-cycle of the AC voltage source. A load circuit includes multiple AC line-voltage switching devices and the multiple electrical loads. Each AC line-voltage switching device controls the application of power from the AC voltage source to a respective one of the electrical loads. An input circuit senses the multiple AC line-voltage switching devices and generates a single output signal which is representative of the states of the multiple AC line-voltage switching devices. A processing circuit determines the states of the multiple AC line-voltage switching devices based upon the synchronization signal and the single output signal.

Abstract: A temperature protection device and method for an air-cooled housing containing electronic equipment is disclosed. A fan forces air to circulate through the housing with air being expelled from the housing at a normal operating temperature inside the housing and with air at an ambient temperature being drawn into the housing. A temperature sensitive element such as a temperature sensitive switch is mounted to the housing such that it is maintained cooler than the operating temperature in the housing as a result of air being drawn into the housing and such that it is exposed to the operating temperature only upon failure of the air circulation. The temperature sensitive element or switch generates an interrupt signal when it senses a response temperature which is near the operating temperature in the housing. In the case of a temperature sensitive switch, power to the electronic equipment may be shut down by the switch.

Abstract: A device for operating a side airbag is capable of rapidly deploying the side airbag and utilizing a physical collision force without an ECU. The device comprises a U-shaped beam deformed in the event of a crash to generate heat, a plurality of pairs of plate springs fixed along an inner base surface of the U-shaped beam at a predetermined interval, a thin metal plate fixed on the ends of each of the pairs of plate springs, a shape memory alloy member being capable of bending the pair of plate springs against resilient force thereof at a transformation temperature, and connecting the pair of plate springs, a contact electrically connected to the squib and being in contact with the thin metal plate by the deformation of the shape memory alloy member, and a temperature holding portion for constantly keeping the temperature of the U-shaped beam lower than the transformation temperature of the shape memory alloy member.

Abstract: A heat-sensitive alarm trigger is used to set off a fire alarm system. The alarm circuit is triggered either when a resistance across two sensor leads, between which the alarm trigger is connected, falls below the rated trigger resistance or when an emf of a certain strength is produced between two electrodes of the trigger. The heat-sensitive alarm trigger comprises a laminate structure which includes an optionally perforated first electrode layer and a second electrode layer. A hydrated material layer is disposed between the two electrode layers. When the hydrated material is heated above a given alarm trigger temperature, moisture is given off and the barrier layer becomes sufficiently conductive so as to trigger the alarm. This is either caused by lowering the resistance of the hydrated material to below the rated trigger resistance or by producing a sufficient emf between the electrodes which have different electrode potentials.

Abstract: A heat-sensitive alarm trigger is used to set off a fire alarm system having an alarm circuit with a rated trigger resistance. The alarm circuit is triggered when a resistance across two sensor leads, between which the alarm trigger is connected, falls below the rated trigger resistance. The heat-sensitive alarm trigger comprises a laminate structure which includes an optionally perforated first electrode layer and a second electrode layer. A barrier material layer which is disposed between the two electrode layers has a resistance above the rated trigger resistance. A layer of hydrated material is disposed on the perforated electrode layer. When the hydrated material is heated above a given alarm trigger temperature, moisture is given off through the holes in the first electrode and, as a result, the barrier layer becomes sufficiently conductive so as to lower a resistance across the electrodes to below the rated trigger resistance.

Abstract: An overtemperature sensing and signaling circuit for electronic trip units includes a voltage divider (16) and a trigger circuit (18). The voltage divider is formed of a first resistor (R1) and a positive coefficient resistor (PT1). The trigger circuit is formed of a first bipolar transistor (Q1) of the PNP-type conductivity and a second bipolar transistor (Q2) of the NPN-type conductivity.

Abstract: A machining fluid temperature deviation alarm device is attached to an electrical discharge machining device which, having a temperature sensor (S1) for machining fluid temperature detection and a cooler (2) for machining fluid cooling, controls the cooler in response to a temperature sensor output signal, thereby controlling the machining fluid temperature within an allowable range. The alarm device employs a second temperature sensor (S2) for determining whether the machining fluid temperature is within a predetermined temperature range set by means of a second setter (5) and encompassing the allowable machining fluid temperature range.

Abstract: An abnormal temperature detector for an electronic apparatus includes a plurality of temperature detectors, an abnormality detector, and a power supply controller. The plurality of temperature detectors are arranged at least at one detection point of a rack, of an electronic apparatus, in which a plurality of wiring boards having IC elements mounted thereon are housed, and respectively output detection outputs when a temperature at the detection point becomes a preset temperature or more. The abnormality detector detects that detection outputs are output from all the temperature detectors at the detection point. The power supply controller interrupts a power supply of the apparatus in response to an abnormality detection output from the abnormality detector.

Abstract: An aural or visual alarm is arranged to be actuated upon leaving a door to an appliance open longer than a preselected period of time. An automatically resettable disarming device may be included to permit leaving the door open intentionally for an extended time to permit appliance cleaning or the like.

Abstract: An apparatus for protecting pipes subjected to freezing temperatures. An electric circuit is provided with a switch that senses the ambient air temperature in the vicinity of a pipe to be tested. The switch is set to activate an alarm when the water in the pipe reaches about 4.degree. C. to about 5.degree. C. The electric circuit is contained within a housing that is perforated to permit the sensing of the ambient air temperature. The housing may be provided with velcro straps to secure the housing to a pipe to be tested.

Abstract: In a combination heat-sensing fire detector provided with a differential diaphragm electric contact and a contact which operates at a predetermined temperature, a shape memory effect element is used as a device which operates at a predetermined temperature. The fire detector can generate a fire alarm without fail even when the ambient temperature rises very slowly.

Abstract: An improved fire detector vented to atmosphere, capable of closing or opening an alarm circuit on the happening of either two events, when the rate of rise of the temperature of the ambient atmosphere exceeds a predetermined prescribed rate of rise of temperature and when the temperature of the ambient atmosphere exceeds a predetermined fixed temperature, the detector being of the type comprising a base supporting a diaphragm enclosing a space between the base and diaphragm, a shell secured to the base enclosing the diaphragm, vent apertures through the base from the space between the diaphragm and shell, and between the diaphragm and base, to the back of the detector, and a fin for collecting heat from the ambient atmosphere. The vent aperture permits the spaces between the diaphragm and base, and shell and base to be vented to atmosphere under normal expansion and contraction of the ambient atmosphere.

Abstract: An automatic freeze control (10) includes a temperature sensor (18) and a valve (20) connected to the water line (22). Control circuitry (36, 38, 40, 42, 44 and 46) is responsive to the line water temperature continuously monitored by the sensor (18) to selectively open the valve (20) for increased periodic flow with decreasing temperature.

Abstract: A temperature sensor for a temperature limiter is made up of an outer tube and a number of inner component rods. The temperature sensor extends transversely over the top side of a moulding of a heating system for a glass-ceramic cooking unit. The heating system comprises a central heating surface and an outer connectable heating surface disposed in a circle therearound. Disposed in the zone of the central heating surface is an inner component rod whose coefficient of expansion is lower than that of the outer tube, while in the zone of the connectable heating surface the component rods have a higher coefficient of expansion than the outer tube.

Abstract: A portable room security alarm features a smoke detector alarm, a motion sensing intrusion alarm, a temperature sensing alarm, and a digital display alarm clock. The security alarm includes a deployable thermally conducting mounting clip for mounting the alarm at the top of a door with the clip extended to pass around the upper edge of the door. A deployable temperature sensor probe may be attached to the clip to give early warning of a fire outside the door. The temperature probe may alternatively be attached to other metallic structures passing through the door frame, e.g. door knobs, hinges, etc. Large ventilating apertures in an extensible telescoping housing allow access of smoke to the smoke sensor, and with the housing closed the sensor is sealed off against long term contamination.

Abstract: A water valve is disclosed for use in passenger vehicle heating systems. The valve includes a cylindrical metallic socket having a heat accepting surface portion connected to the valve housing and in fluid communication with fluid flowing through the valve. The position of the heat accepting surface portion relative to a rotatable butterfly valve member results in a vortex flow condition across the face of the heat accepting surface portion, thereby providing fast heat transfer from the fluid to the socket.

Abstract: A contact-controlled capacitive switching means utilized as a floor or cabin calling transmitter for lifts or the like is designed such that travel or drive commands for the lift are prevented from being generated by the action of heat or, if generated, from being further transmitted to a lift control system. Therefore, a thermal circuit breaker is interconnected between an actuating element, such as a contact button and a coupling member connected to an input of an oscillator. The thermal circuit breaker may be mounted directly at the contact button or at a mounting plate carrying the contact button. A further thermal circuit breaker is interconnected between an output of the switching means and a connection terminal of a signal transmitting line of the lift control system.

Abstract: The signalling system disclosed herein transmits groups of pulses to a plurality of transponders, and each transponder recognizes its address in a particular group of pulses. The group of pulses can reset the system, command a transponder to accomplish a specific function, or command the transponder to do nothing. Information returned from the transponder includes a reference voltage, which can be compared in the controller to continuously determine the margin from alarm of an associated transducer. The transponder further provides a signal identifying itself, and pulse duration signals representing analog signals received from one or more transducers associated with the transponders. No end-of-line termination is required, and branching is possible at any point along the loop.