EP2393073A1 - Method for operating a hazard notification assembly - Google Patents

Abstract

The method involves connecting subscribers (T01-T10) to a central unit (ZE) i.e. alarm central unit, via a two wire line i.e. field bus. An isolator is arranged between an input and an output. Current through the subscribers between the input and the output is measured and compared with a stored maximum value. A representative signal is produced at a processor during exceeding the maximum value. The isolator is opened when exceedance of the maximum value of the current is continued after a sequence of delay times (VZa, Vzb). An independent claim is also included for a hazard notification assembly with a central unit.

Description

The invention relates to a method for operating a hazard alarm system with a central unit (central office or coupler) to which a two-wire line as a field bus several participants are connected in parallel, each of which has an input (A) and an output (B) for the fieldbus, at least a processor, a processor-controlled disconnector between input (A) and output (B), a sensor or actuator and a communication module. The invention further relates to an operating according to this method hazard detection system.

Danger alarm systems with the above-mentioned basic structure have long been state of the art. The central unit supplies the operating voltage via the two-wire line operated as a field bus to the subscribers and communicates with these digitally via defined, usually proprietary protocols. Among other things, the central unit monitors the voltage and the current on the fieldbus to protect the alarm system. If a predetermined maximum value of the current is exceeded, as a rule caused by insulation faults, in the worst case a short circuit, the central unit switches off the operating voltage. As a rule, the alarm system can not be put into operation until the cause of the fault has been eliminated.

The invention has for its object to provide a method for operating such a hazard detection system available that a total failure of the hazard detection system usually avoids as a result of in the fieldbus, ie on the two-wire line or in a particular participant occurred insulation fault.

• der Strom durch den Teilnehmer zwischen dessen Eingang und dessen Ausgang gemessen, mit einem gespeicherten Maximalwert verglichen und bei dessen Überschreitung ein hierfür repräsentatives Signal an den Prozessor erzeugt wird
• und dann, wenn nach Ablauf einer teilnehmerspezifischen Verzögerungszeit die Überschreitung des Maximalwertes des Stromes fortbesteht, der Trenner geöffnet wird.

This object is achieved in that in each participant

• the current measured by the subscriber between its input and its output, compared with a stored maximum value and, when exceeded, a representative signal is generated to the processor
• and then, if after expiration of a subscriber-specific delay time, the exceeding of the maximum value of the current persists, the disconnector is opened.

This solution is based on a state-of-the-art alarm system in which the central unit and the subscribers communicate digitally with one another. The input and the output of the participants are equal, so that the "incoming" fieldbus can also be connected to the output and the "outgoing" fieldbus to the input. The sensors in the subscribers can be, in particular, smoke detectors or burglar alarms. The actuators may e.g. visual or acoustic escape route markings, extinguishing agent controls, and / or triggers for fire doors or smoke flaps. However, the solution according to the invention is also applicable to analog operating systems that work instead of a processor with a simple logic circuit in the subscriber and do not require a communication module.

The solution according to the invention is suitable both for a field bus in the form of a spur line and a ring-shaped closed fieldbus. In both cases, as is known, branch off from the field bus more field buses as stubs.

The core of the invention is that when an insulation fault, hereinafter referred to only as "short circuit" occurs, all participants recognize this error by the current measurement while at the same time, but only the one participant who is wiring the next fault location, his disconnector opens so that the other subscribers located between the subscriber with the open disconnector and the central unit remain fully functional.

The subscriber-specific delay time is determined as a function of the number of other participants located between the respective subscriber and the central unit and, preferably during the commissioning of the alarm system, stored individually in each subscriber.

Preferably, the subscriber-specific delay time VZ is defined as VZ = (N + 1-i) · t, where N is the number of subscribers, i is the physical position number of the subscriber counted by the central unit's serving port, and t is a time interval greater than that Time is required for each participant to complete his functional routine. Under the function routine here are all the participants assigned, usually preprogrammed and cyclically repeating subtasks to understand, that is, those that the participant performs in normal operation, such as periodic queries of the sensors, sending status messages to the center, receiving and processing Command from the headquarters, etc. In addition, in the context of the invention, the Time for the sake of energy saving usually also only at periodic intervals made measurement of the current by the subscriber, the comparison with the stored maximum value and the processing of the comparison result by the processor and for this possibly triggered by this opening the disconnector. The time interval t can be very short, for example of the order of 1 ms.

To increase reliability, the fieldbus is often designed as a loop in current hazard detection systems. In this case, the method according to the invention is that when commissioning the alarm system in each participant, the valid for normal operation current flow direction and a first delay time in the case of power via the A port of the central unit and a second delay time for the case during operation, as soon as an overcurrent ("short-circuit current") is detected, its direction is determined between the input and the output of the subscriber and depending on the determined current flow direction either at Expiration of the first delay time or at the end of the second delay time and in each case still persistent exceeding of the maximum value of the current of the disconnector is opened.

As a result, the availability of the hazard detection system is significantly improved even in the case of a short circuit, because the result of the short circuit location is separated from the fieldbus, because the short circuit immediately adjacent participants ("before" and "behind" the short circuit) both open their disconnectors, if the Central unit feeds the field bus at this time both the A port and the B port.

When the disconnector is opened, a data telegram that is significant for this purpose is preferably sent to the central unit via the communication module. The central unit or the operator thus not only recognizes, as before, that a short circuit has occurred, but the short circuit can be localized immediately and, for example. be output in plain text.

Because in the case of a complete short circuit between the wires of the field bus or the two-wire line embodying this, the operating voltage of at least the subscriber positioned in the nearer region of the short circuit collapses to 0 volts or nearly 0 volts, it must be ensured in another way that the subscribers concerned at least as long be supplied with their operating voltage until the disconnector of the short circuit location next participant (or the disconnector of the participants on both sides of the short circuit location) has opened and all remaining participants receive their operating voltage again from the central unit. If the subscribers have no operating voltage available from an external auxiliary voltage source, they must therefore, when the minimum value of their operating voltage falls below an internal energy store, e.g. a capacitor, sufficiently long, at least until the opening of the relevant disconnector, are supplied.

In addition, the applied operating voltage can be measured in each participant, compared with a stored minimum value, and the comparison result supplied to the processor.

In order to shorten the time until opening of the isolator or disconnector, when the maximum value of the current and / or falls below the minimum value of the operating voltage In each participant an interrupt command for its processor are generated, so that the latter immediately issues the command to open the separator.

It is expedient to activate a signal lamp of this subscriber which identifies this condition when the disconnector is open. This simplifies the search for the error location.

• einen Eingang und einen Ausgang für den Feldbus,
• mindestens einen Prozessor,
• einen von dem Prozessor gesteuerten Trenner zwischen Eingang und Ausgang
• einen Sensor oder Aktor,
• ein Modul zur Messung des Stromes zwischen dem Eingang und dem Ausgang des Teilnehmers und
• ein Kommunikationsmodul zum Austausch von Datentelegrammen mit der Zentraleinheit und hat erfindungsgemäß desweiteren
• mindestens einen Speicher für mindestens eine teilnehmerspezifische Verzögerungszeit,
• einen weiteren Speicher zur Speicherung mindestens des Betrages des im Normalbetrieb zulässigen Maximalwertes des Stromes zwischen dem Eingang und dem Ausgang des Teilnehmers,
• eine Auswerteschaltung, die den gemessenen Strom mit dem gespeicherten Maximalwert vergleicht und das Vergleichsergebnis an den Prozessor liefert
• und einen Energiespeicher zum Betrieb des Prozessors bei Wegfall der Betriebsspannung des Teilnehmers.

The invention further relates to a hazard alarm system which can be operated according to the proposed method. This alarm system comprises a central unit (central unit or coupler) to which a plurality of subscribers are connected in parallel via a two-wire line as field bus. Every participant has

• an input and an output for the fieldbus,
• at least one processor,
• a processor controlled divider between input and output
• a sensor or actuator,
• a module for measuring the current between the input and the output of the subscriber and
• a communication module for exchanging data messages with the central unit and according to the invention furthermore
• at least one memory for at least one subscriber-specific delay time,
• another memory for storing at least the amount of the maximum value of the current permissible in normal operation between the input and the output of the subscriber,
• an evaluation circuit which compares the measured current with the stored maximum value and supplies the comparison result to the processor
• and an energy storage for operating the processor when the operating voltage of the subscriber.

If the fieldbus is designed as a loop and can be fed accordingly by the central unit via its A port and / or its B port, the current measuring module determines in addition to the amount of current and its sign, i. its direction between the A port and the B port of the subscriber.

The hazard alarm system may additionally comprise a voltage measuring module which compares the voltage applied to the input or the output of the subscriber operating voltage with a stored minimum value and supplies the comparison result to the processor, which interprets an undershooting of the stored minimum value of the operating voltage as an interrupt command.

• Fig. 1: ein Schema einer Gefahrenmeldeanlage
• Fig. 2: ein Blockschaltbild eines der Teilnehmer dieser Gefahrenmeldeanlage
• Fig. 3: eine symbolische Darstellung der Teilnehmerzustände nach dem Auftreten eines Kurzschlusses.

The invention will be explained with reference to the drawing, which refers to a highly simplified illustrated embodiment. It shows:

• Fig. 1 : a scheme of a hazard detection system
• Fig. 2 : a block diagram of one of the participants of this alarm system
• Fig. 3 : a symbolic representation of the participant states after the occurrence of a short circuit.

In FIG. 1 is, simplified, the scheme of a hazard detection system shown.

It comprises a central unit ZE, which is the alarm center, in the case of larger systems a sub-center or an alarm center or a sub-center connected coupler can act. The central unit ZE has a connection A and a connection B for a guided in the ring, embodied by a second wire line field bus whose beginning is accordingly connected to the terminal A and the end to the terminal B of the central unit ZE. The fieldbus supplies eg up to 123 subscribers with their operating voltage and at the same time serves the digital communication between the central unit and these subscribers. For the sake of simplicity, only 10 subscribers are represented in a ring R. These have the item numbers T01 to T10 counted from the connection A to the connection B or the position numbers (T01) to (T10) counted from the connection B to the connection A. Each participant has a two-pole input a and a two-pole output b.

The participants can have both the function of sensors and the function of actuators. For example, T01 to T03 may be fire detectors, T04 may be an optical or acoustic escape route identifier, T05 may be an extinguishant controller, and so on.

The central unit can supply the ring R in an operating mode A via the connection A and / or in operating mode B via the connection B with operating voltage. The same applies to the communication between the central unit ZE and the participants. As is known per se, the central unit ZE comprises a logic which determines the operating mode as a function of the state of the fieldbus.

For example, if the logic detects an open circuit or a short on the fieldbus in A-mode, it will attempt to be ready for operation by switching to B-mode or A / B mode, ie powering the fieldbus and communicating between them Terminals A and B off, to maintain.

Each of the participants in Fig. 1 has to carry out the proposed operating procedure in FIG. 2 Structure shown as a block diagram. If the fieldbus is not operated as a ring but only as a stitch, the structure is simplified accordingly.

The subscriber has input terminals a + and a- as well as output terminals b + and b-. The example coming from the terminal A of the central unit, the field bus embodying two-wire line is connected to the input terminals a + and a-. The continuing two-wire line is connected to the output terminals b + and b-, respectively. Between the terminals a + and b + is a closed in regular operation disconnector TR, for example, a relay contact or a controlled semiconductor switch. The disconnector TR can also lie between the terminals a and b. Preferably, the separator TR comprises two series-arranged FETs as switches, which are selectively, ie programmatically, individually or jointly switchable via switching commands. A current sensor IS, for example in the form of a current measuring resistor whose current-proportional voltage drop measures an evaluation circuit AS, compares with a maximum value stored in a memory MA and the result and, in the case of an annularly guided field bus, also the direction of current flow to a processor between the terminals a and b transmitted μP. Depending on the application, the processor μP is furthermore connected to a sensor or an actuator S / A, for example to the detection circuit of a scattered light smoke detector or to the control circuit of an extinguishing agent system. The processor sends status messages to the central unit ZE in via a communication module KM Fig. 1 and receives from these commands in the form of data telegrams. Furthermore, the processor μP controls the switching state of the disconnector TR. The communication module KM can also report the switching state of the disconnector TR to the central unit ZE.

The evaluation circuit AS queries via the current sensor IS, the current on the fieldbus, that is, the current through the subscriber, in short intervals periodically. The maximum value is preferably stored in the memory MA during the commissioning of the alarm system, as well as the current flow direction in normal operation of the ring. If the maximum value is exceeded, the processor μP starts a timer ZG. Depending on the direction (the sign) of the current, the processor determines μP after expiration of either a stored delay time VZa or after the lapse of a stored delay time VZb, whether the exceeding of the maximum value of the current characterizing signal persists. Only if this is the case does the processor μP trigger the opening of the disconnector TR. The resulting performance is then based on Fig. 3 be explained.

If the current through the subscriber significantly exceeds the predetermined maximum value, for example in the event of a short circuit, the operating voltage at terminals a and b breaks down. Therefore, the processor .mu.P receives its internal operating voltage from an energy store ES, for example a capacitor, which is dimensioned so that at least the processor .mu.P and the current measuring circuit IS, AS remain operable at least until the disconnector TR is opened. The energy store ES is connected to the line between a + and b + via diodes D1 and D2 on both sides of the disconnector TR in order to prevent the energy store ES from discharging via the short-circuit point in the event of a short circuit. Optionally, the subscriber has a voltage measuring module Sa and Sb on the input side and output side.

The voltage measuring modules compare the operating voltage present at the input and the output of the subscriber with a stored minimum value and, if not reached, supply a signal to the processor which can interpret this signal as an interrupt command to execute certain routines such as the control or interrogation of the sensor or actuator S /. A or the data traffic with the communication module KM cancel and immediately start the timer ZG. This shortens the time until the necessary opening of the disconnector TR.

The illustrated function blocks are only for explanation. In practice, certain functions and / or the not shown A / D converters can be integrated in the processor μP and all values to be stored can be stored in a common memory IC.

The operating behavior of a hazard detection system according to Fig. 1 with participants according to Fig. 2 and in particular the function of the subscriber-specific delay times VZa and VZb is determined on the basis of Fig. 3 explained, in the case of an overcurrent or short circuit by an error between the participants 06 and 07. It is assumed that the alarm system or the central unit ZE according to Fig. 1 the fieldbus is supplied via the A connection as well as via the B connection at least as soon as the short circuit occurs, which is also detected by the central unit.

In Fig. 3 in the ordinate direction, the subscribers T01 to T10 are plotted in the abscissa direction, the delay times VZa and VZb rising from left to right in a symbolic time grid.

Each of the participants T01 to T10 is assigned a specific delay time for him. This depends on its "distance" from the respective feeding connection of the central unit ZE and the longer, the closer the relevant subscriber is to the feeding connection. By "distance" is meant the number of further participants up to the (respective) connection.

The respective delay times may be determined according to the relationship VZ = (N + 1-i) · t, where N is the number of subscribers, in the present example 10, i the subscribers' physical position number counted by the serving terminal of the central unit ZE and t Time interval is that has been chosen at least so large that each participant on the basis of Fig. 2 in the case of a current exceeding the stored maximum current can be processed until the necessary opening of the separator TR, without overlapping these processes of the individual participants in time.

Because the subscriber T01, as seen from the A port of the central unit ZE, the first subscriber, but when fed via the B port of the central unit ZE is the last subscriber (T10), the subscriber T01 is at startup of the system as a delay time VZa of Value t10 and assigned as delay time VZb the value t1 for storage, etc. Conversely, for example, the participant T10 as the delay time VZa the value t1 and assigned as delay time VZb the value t10 and stored in this. Consequently, the subscriber T01 has the longest delay time t10 [VZa] and the shortest delay time t1 [VZb], the subscriber T09 the delay times t9 [VZa] and t2 [VZb], etc.

If, as assumed here, a fault location between the subscribers T06 and T07 results, which leads to an overcurrent ("short circuit"), the subscribers T07 to T06 are supplied (only) with operating voltage via the A connection; T10, however, via the B port. Therefore, for T01 to T06 only the delay times VZa from t10 to t5 are relevant and marked as circles. The delay times t4 [VZa] to t1 [VZa], which are not relevant in the case under consideration but are also stored, are shown as dashed circles. Analogously, only the relevant delay times t7 [VZb] to t10 [VZb] are represented as circles for the subscribers T10 to T07. The further stored delay times t1 [VZb] to t6 [VZb] are also not shown for the sake of clarity.

• Alle Teilnehmer T01 bis T10 erkennen diesen im Zeitpunkt t0 auftretenden Zustand gleichzeitig. Somit startet jeder Teilnehmer über seinen Prozessor µP seinen Zeitgeber ZG.
• Gesteuert von der Information über die Richtung des Stromes, also abhängig davon, ob der betreffende Teilnehmer ab t0 von dem A-Anschluss oder dem B-Anschluss der Zentraleinheit ZE gespeist wird, wartet der Prozessor µP jedes Teilnehmers entweder bis zum Ablauf seiner Verzögerungszeit VZa, im Fall der Fig. 3 die Teilnehmer T06 bis T01, oder
• bis zum Ablauf der Verzögerungszeit VZb, im Fall der Fig. 3 die verbleibenden Teilnehmer T07 bis T10. Bis zum Ablauf der jeweiligen Verzögerungszeit oder erst bei deren Ablauf prüft der jeweiligen Prozessor µP, ob die Information über den Überstrom noch fortbesteht. Wenn das der Fall ist, löst der Prozessor µP des betreffenden Teilnehmers das Öffnen des Trenners TR dieses Teilnehmers aus.

As a result, for the fault location between subscribers T06 and T07, which generates in each subscriber a current greater than the stored maximum value MA, the following results:

• All subscribers T01 to T10 recognize this state occurring at time t0 simultaneously. Thus, each participant starts his timer ZG via his processor μP.
• Controlled by the information about the direction of the current, that is, depending on whether the participant in question is fed from t0 of the A port or the B port of the CPU ZE, waiting for the processor μP each participant either until the expiry of its delay time VZa, in the case of Fig. 3 the participants T06 to T01, or
• until expiration of the delay time VZb, in the case of Fig. 3 the remaining participants T07 to T10. Until the end of the respective delay time or until it expires, the respective processor μP checks whether the information about the overcurrent still persists. If this is the case, the processor uP of the relevant subscriber triggers the opening of the disconnector TR of this subscriber.

Because the error location is between the subscribers T06 and T07, the subscriber T06 with the shortest delay time t5 [VZa] and also the subscriber T07 with the shortest delay time t7 [VZb] are the first to recognize this state. These delay times are additionally marked with "X". These two participants consequently open their separators TR. Thus the fault location is separated from the ring bus. The participants T01 to T05 and the participants T08 to T10 recognize, however, at the end of their respective longer delay times VZa or VZb that the maximum permissible value MA of the current is (again) below. Their disconnectors TR therefore remain closed. Consequently, the previous functioning of the hazard alarm system is restored at least for the participants T01 to T05 and T08 to T10. The functionality can be completely restored, ie also for the subscribers T06 and T07 on both sides of the fault location, if these two subscribers in turn can also process signals from their sensors or commands for their actuators after opening their disconnectors.

The command of the processor μP, which triggers the opening of the disconnector TR, can be used at the same time for switching on an LED (not shown), which facilitates the location of the fault location for the maintenance personnel.

Claims (11)

Method for operating a hazard alarm system with a central unit (central office or coupler), to which two subscribers (T01 to T10) are connected in parallel via a two-wire line as field bus, each of which has an input (a) and an output (b) for the fieldbus, at least one processor (μP), a processor controlled disconnector TR between input (a) and output (a), a sensor or actuator (S / A) and a communication module (KM), characterized in that in each participant ( T01 to T10) - The current measured by the participant between its input (a) and its output (b), compared with a stored maximum value and its exceeding a representative signal to the processor (μP) is generated - And then, if after expiry of a subscriber-specific delay time (VZ) exceeding the maximum value of the current persists, the disconnector (TR) is opened. Method according to Claim 1, characterized in that the subscriber-specific delay time (VZ) is determined as a function of the number of other subscribers located between the respective subscriber and the central unit (ZE) and is stored in the respective subscriber when the security alarm system is put into operation. Method according to Claim 1 or 2, characterized in that the subscriber-specific delay time VZ is defined as VZ = (N + 1-i) · t, where N is the number of subscribers (T01 to T10), i is the number of subscribers (A, B) the central unit (ZE) counted physical position number of the subscriber and t is a time interval which is greater than the time required for the subscriber to complete his function routine. Method according to one of Claims 1 to 3, for a hazard alarm system whose central unit (ZE) has an A connection for the beginning of the fieldbus and a B connection for the end of the fieldbus and the latter via the A connection and / or the B Connection, characterized in that when commissioning the alarm system in each participant applicable for the normal operation current flow direction and a first delay time (VZa) for the case of power supply via the A port of the central unit (ZE) and a second delay time ( VZb) is stored in the case of power supply via the B port of the central unit (ZE), and that in operation when exceeding the stored maximum value of the current whose direction between the input (a) and the output (b) of the subscriber is determined and in that, depending on the determined current flow direction, either at the end of the first delay time (VZa) or at the expiration of the second delay opening time (VZb) and continued exceeding of the maximum value of the current of the disconnector (TR) is opened. Method according to one of Claims 1 to 4, characterized in that, when the disconnector (TR) is opened, a data telegram significant for this purpose is sent to the central unit (ZE) via the communication module (KM). Method according to one of Claims 1 to 5, characterized in that the subscribers (T01 to T10) are supplied from an internal energy store when they fall below the minimum value of their operating voltage. Method according to one of claims 1 to 6, characterized in that measured in each participant (T01 to T10), the applied operating voltage, compared with a stored minimum value and the comparison result to the processor (μP) is delivered. Method according to one of claims 1 to 7, characterized in that falls below the minimum value of the operating voltage and / or when exceeding the maximum value of the current in each participant (T01 to T10), an interrupt command for its processor (μP) is generated. Method according to one of claims 1 to 8, characterized in that when the disconnector (TR) an indicator light of the subscriber is activated. Danger alarm system with a central unit (central unit or coupler) to which two subscribers (T01 to T10) are connected via a two-wire line as a field bus, each of which an input (a) and an output (b) for the fieldbus, at least one processor (μP), a separator (TR) controlled by the processor (μP) between input (a) and output (b) a sensor or actuator (S / A), a current sensor (IS) for measuring the current between the input (a) and the output (b) of the subscriber and a communication module (KM) for exchanging data telegrams with the central unit (ZE), marked by at least one memory (VZa / VZb) for at least one subscriber-specific delay time (VZ), a further memory for storing at least the amount of the maximum value of the current permissible in normal operation between the input (a) and the output (b) of the subscriber, - An evaluation circuit (AS), which compares the measured current with the stored maximum value and the comparison result, in the case of a ring-connected field bus and the direction of the current to the processor (μP) supplies - And an energy storage for operation of the processor (μP) in case of loss of operating voltage of the subscriber. Security alarm system according to claim 10, characterized by a voltage measuring module which compares the voltage applied to the input (a) or the output (b) of the subscriber operating voltage with a stored minimum value and at low voltage, a signal to the processor (μP) delivers.

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