Method and device for measuring a line resistance of control lines in hazard warning and control systems

Abstract

A method for measuring a line resistance R.sub.L (7) and determining control line (16) faults in a hazard warning and control system. The control lines (16) connect a control device (20) to an actuator (10) using an actuation voltage U.sub.A in the case of an event and supplies the actuator (10) with a monitoring voltage U.sub.M in the case of a monitoring process using a monitoring module (21). Furthermore, the control device (20) has a constant current sink (6), which can be activated by a microcontroller (1), and a switchover device (5). In order to determine the line resistance R.sub.L (7), a constant voltage supply is provided in a measurement time interval t.sub.M by an energy store (9) integrated into the monitoring module (21) and is fed back to the control device (20), and the switchover device (5) deactivates the monitoring voltage U.sub.M supply from the control device (20) to the actuator (10) during the entire measurement time interval t.sub.M.

Claims

1. A method for measuring a line resistance R.sub.L (7) and thus for determining faults of control lines (16) in a hazard warning and control system, the control lines (16) connecting a control device (20) to an actuator (10), the control device (20) in the case of an incident driving the actuator (10) using a drive voltage U.sub.A and in the case of monitoring supplying the actuator (10) with a monitoring voltage U.sub.M, there being arranged at or in the actuator (10) a monitoring module (21) at the end of the control lines (16), the control device (20) furthermore exhibiting a constant current sink (6) connectable via a microcontroller (1) or a connectable load resistance and a switching device (5) and the beginning of the control lines (16) being arranged on the control device (20), wherein for determining the line resistance R.sub.L (7) a constant voltage supply is provided in a measurement time interval t.sub.M by means of an energy storage (9) integrated into the monitoring module (21), and fed back into the control device (20), and in the entire measurement time interval t.sub.M the switching device (5) switches off the supply of monitoring voltage U.sub.M provided by the control device (20) for the actuator (10).

2. The method according to claim 1, wherein the following method steps are carried out: providing a monitoring voltage U.sub.M at the contacts (17) of the control device (20) for electrically tying the control lines (16) for the duration of a time interval t.sub.1, charging the energy storage (9) of the monitoring module (21) by means of the applied monitoring voltage U.sub.M for the duration of the time interval t.sub.1, switching off the monitoring voltage U.sub.M after the expiration of the time interval t.sub.1, generating a regulated voltage U.sub.0 from the energy storage (9) using a voltage regulator (8), measuring a resulting voltage value U.sub.1 at the contacts (17) using an A/D converter (2) and storing the voltage value U.sub.1 in a memory (22), driving the constant current sink (6) by means of the microcontroller (1) and impressing a current value I.sub.2 into the control lines (16), measuring a voltage value U.sub.2 using the A/D converter (2) at the contacts (17), that is generated by the impressed current value I.sub.2, storing the voltage value U.sub.2 in the memory (22) and calculating the line resistance R.sub.L (7), the duration of all method steps after the expiration of the time interval t.sub.1 determining the measurement time interval t.sub.M.

3. The method according to claim 2, wherein the line resistance R.sub.L (7) is calculated by forming the quotient from the difference of the voltage values U.sub.1 and U.sub.2 and the difference of the associated currents.

4. The method according to claim 1, wherein measurement of the line resistance R.sub.L (7) takes place periodically, aperiodically and/or on demand.

5. The method according to claim 1, wherein when a predefined limit value for the line resistance R.sub.L (7) is exceeded, the microcontroller (1) generates a fault signal that signals a fault of the control lines (16).

6. The method according to claim 5, wherein a slow developing wire breakage is detected as a fault of the control lines (16).

7. The method according to claim 5, wherein faulty installation with increased values of the line resistance R.sub.L (7) of the control lines (16) is detected as fault of the control lines (16).

8. The method according to claim 5, wherein the fault of the control lines (16) is indicated optically and/or acoustically.

9. A device for measuring a line resistance R.sub.L (7) and thus for determining faults of control lines (16) in a hazard warning and control system, comprising: a control device (20) that exhibits a constant current sink (6) connectable via a microcontroller (1) or a connectable load resistance, a switching device (5) and a voltage source (4) for generating a monitoring voltage U.sub.M, and a monitoring module (21) that is arranged at the end of the control lines (16) at or in an actuator (10), the beginning of the control lines (16) being arranged at the control device (20), wherein the monitoring module (21) exhibits an energy storage (9) for generating and feeding-back a constant voltage supply into the control device (20) in a measurement time interval t.sub.M for determining the line resistance R.sub.L (7), and the switching device (5) and the microcontroller (1) is designed and formed such that the supply of monitoring voltage U.sub.M provided by the control device (20) for the actuator (10), is switched off in the entire measurement time interval t.sub.M.

10. The device according to claim 9, wherein the control device (20) is set up and designed such that the switching device (5) can be controlled by means of the microcontroller (1), for switching on and off the voltage supply of the actuator (10), preferably the monitoring voltage U.sub.M, and/or for driving the actuator (10) using a drive voltage U.sub.A in the event of an incident.

11. The device according to claim 9, wherein the control device (20) is designed for periodically and/or aperiodically measuring the line resistance R.sub.L (7) and/or for measuring on demand.

12. The device according to claim 9, wherein the monitoring module (21) exhibits a terminating resistance R.sub.EOL (12) connected in series to an inside resistance of the actuator (10), a limit-value switch (14) and a switch (13), the terminating resistance R.sub.EOL being designed such that the voltage applied to the actuator (10) is below the minimum drive voltage when the monitoring voltage U.sub.M is applied.

13. The device according to claim 9, wherein the control device (20) is set up and designed such that when a predefined limit value for the line resistance R.sub.L (7) is exceeded the microcontroller (1) generates a fault signal that signals a fault of the control lines (16).

14. The device according to claim 9, wherein the energy storage (9) represents a capacitor or a battery that are dimensioned such that they ensure a constant voltage supply during the measurement time interval t.sub.M.

15. The device according to claim 9, wherein the actuator (10) represents a solenoid valve.

16. The device according to claim 9, wherein the control device (20) is designed as constituent part of a fire detection panel and/or extinguishing control panel (23).

17. The device according to claim 16, wherein the control device (20) represents a control group module (24) or a ring bus participant module.

18. The device according to claim 9, wherein the control device (20) is designed as an addressable module.

Description

DRAWINGS

(1) Further advantageous or convenient features and developments of the disclosure derive from the sub claims as well as the description. Preferred and advantageous embodiments are illustrated in the attached drawings. In the drawings:

(2) FIG. 1 illustrates a schematic block diagram of the device for the measurement of the line resistance R.sub.L;

(3) FIG. 2 illustrates a schematic block diagram of a second exemplary embodiment;

(4) FIG. 3 illustrates a schematic representation of the control device as a control group module of a fire detection and/or extinguishing control panel;

(5) FIG. 4 illustrates a schematic representation of the control device as an addressable module on a ring bus line of a fire detection and/or extinguishing control panel.

DETAILED DESCRIPTION

(6) A particularly preferred development of the device for measuring a line resistance R.sub.L 7 and thus for determining faults of control lines 16 in a hazard warning and control system is illustrated schematically in FIG. 1. The device comprises two functional parts, the control device 20 and the monitoring module 21, which is arranged at the end of the control lines 16 at or in an actuator 10, wherein the beginning of the control lines 16 is arranged at the contacts 17 at the control device 20. The end of the control lines is connected to the monitoring module 21 at the connecting contacts 18.

(7) Various embodiments are used for the arrangement of the monitoring module 21 at or in the actuator 10, which are not illustrated. In a preferred embodiment the monitoring module 21 is located in a separate housing and is directly attached to the actuator 10 via the electrical contact points 19. It is crucial that there are no further line connections between the monitoring module 21 and the actuator 10 in which a slow developing wire breakage can occur. In a further preferred embodiment the monitoring module 21 is integrated into the housing of the actuator 10 as a pluggable and replaceable module, wherein the circuit of the actuator 10 exhibits receiving means to plug the module and the electrical contact points 19. In a particularly preferred embodiment the monitoring module 21 is integrated into the circuit of the actuator 10 and thus constitutes an integrated monitoring module 21. Both for the design variant of the monitoring module 21 as a replaceable module and as an integrated monitoring module 21 the terminal contacts 18 are located on or in the housing of the actuator 10.

(8) The control device 20 exhibits a constant current sink 6 connectable via a microcontroller 1, a switching device 5 and a voltage source 4 for generating a monitoring voltage U.sub.M. Instead of the constant current sink 6 a connectable load resistance can be arranged as well. A switching device 5, preferably an electronic one with three switch positions A, B and C, and a memory 22 are furthermore arranged in the control device 20. The control device 20 is also equipped with a voltage source 3 for generating the activation voltage U.sub.A of the actuator 10. In switch position A of the switching device 5 the monitoring voltage U.sub.M is applied at the contacts 17, at the beginning of the control lines 16. In switch position B of the switching device 5 there is no voltage at the contacts 17, at the beginning of the control lines 16, i.e. the voltage supply of the actuator 10 is switched off on the side of the control device 20.

(9) The memory 22 can be integrated into the microcontroller 1 or in a further microcontroller or microprocessor of the control device 20, or, as presented, it can be designed as a separate component.

(10) As illustrated in FIG. 1, the monitoring module 21 exhibits an energy storage 9 for generating a constant voltage supply in a measurement time interval t.sub.M for determining the line resistance R.sub.L 7. In a particularly preferred embodiment this energy storage 9 is an adequately dimensioned capacitor.

(11) The switching device 5 and the microcontroller 1 are designed and formed such that the voltage supply of the actuator 10 is switched off in the entire measurement time interval t.sub.M on the side of the control device 20. For this purpose appropriate software is implemented in the microcontroller 1. Here the switching device 5 has switch position B, shown in FIG. 1.

(12) The control device 20 is set up and designed such that the switching device 5 can be controlled by means of the microcontroller 1, for switching on and off the voltage supply, in particular the monitoring voltage of the actuator 10 and/or for activating the actuator 10 using an activation voltage U.sub.A in the event of an incident. For providing the activation voltage U.sub.A the switching device 5 is switched to switch position C.

(13) Through the software implemented in the microcontroller 1, the control device 20 is designed such that the line resistance R.sub.L 7 is measured periodically and/or aperiodically and/or on demand.

(14) An alternative development of the inventive device for measuring the line resistance R.sub.L 7 is schematically illustrated in FIG. 2. In the monitoring module 21 a terminating resistance R.sub.EOL 12, connected in series to the internal resistance of the actuator 10, is additionally arranged. In the illustrated case of monitoring, the switching device 5 is in switch position A for providing the monitoring voltage U.sub.M and the terminating resistance R.sub.EOL 12 together with a series resistor 15 of the voltage source 4 for generating the monitoring voltage U.sub.M in the control device 20 and the internal resistance of the actuator 10 form a voltage divider. The voltage that thereby ensues in the measuring circuit of the control device 20 is measured with the A/D converter 2 and evaluated by the microcontroller 1.

(15) In both design variants of the inventive device from FIG. 1 and FIG. 2 the microcontroller 1 switches the switching device 5 into switch position C at the activation of the actuator 10 in the event of an incident. The actuator 10 is here supplied with the activation voltage U.sub.A, for example 24V DC.

(16) In the design variant that is presented in FIG. 2 a limit-value switch 14 that is additionally arranged in the monitoring module 21, together with an additionally arranged switch 13 ensures that the terminating resistance R.sub.EOL 12 is shorted and thus at activation in the event of an incident the whole activation voltage U.sub.A is applied to the actuator 10.

(17) A further design variant of the inventive device is presented in FIG. 3. The control device 20 is designed here as an addressable module on a ring bus line of the fire detection panel and/or extinguishing control panel 23. The ring bus line is connected to the ring bus participant module 25 as for supply and signaling, which is preferably arranged in the fire detection panel and/or extinguishing control panel 23. Further addressable ring bus participants 27, preferably fire detectors, are arranged on this ring bus line. Thus the control device 20, designed as an addressable module, is itself a ring bus participant 27. This has the advantage that an address is assigned to fault messages of a detected slow developing wire breakage and thus the fault message is associated with a defined control line in the building at a particular place.

(18) In FIG. 4 a further advantageous design of the inventive device is schematically presented. The control device 20 represents here a control group module 24 of a fire detection panel and/or extinguishing control panel 23 and thus is designed as a component of a fire detection panel and/or extinguishing control panel 23.

(19) The presentation of the functional elements of the inventive device in FIG. 1 now illustrates the inventive method in a particularly preferred design.

(20) In switch position A of the switching device 5 in normal operation, that means in the case of monitoring when no activation of the actuator 10 occurs in the event of an incident, the energy storage 9 of the monitoring device 21 is charged with a monitoring voltage U.sub.M to a specific voltage. This monitoring voltage U.sub.M is provided by the voltage source 4. The measurement of the line resistance R.sub.L 7 and thus the line monitoring for faults takes place preferably periodically: The monitoring voltage U.sub.M of the actuator 10 is switched off on the side of the control device 20, through switching the switching device 5 into switch position B. The switching device 5 remains in this switch position B during the entire measurement time interval t.sub.M. In this measurement time interval t.sub.M the voltages U.sub.1 and U.sub.2 are measured. The voltage regulator 8 of the monitoring module 21 is now supplied from the energy storage 9 and feeds the regulated constant voltage back into the control device 20. This voltage value U.sub.1 is measured by the control device 20 using the A/D converter 2 and the microcontroller 1 and is stored in the memory 22. Subsequently the constant current sink 6 is triggered with a current value I.sub.2. This constant current sink 6, too, is supplied by the energy storage 9 and the voltage regulator 8. Then a new voltage measurement is done with the value U.sub.2 in the control device 20 and the microcontroller 1 calculates the line resistance R.sub.L 7 according to a predefined calculation rule.

(21) The method for measuring a line resistance R.sub.L 7 and thus for determining faults of control lines 16 in a hazard warning and control system is characterized in particular in that for determining the line resistance R.sub.L 7 a constant voltage supply is being provided in a measurement time interval t.sub.M by means of an energy storage 9 integrated into the monitoring module 21 and in the entire measurement time interval t.sub.M the switching device 5 switches off the voltage supply of the actuator 10 on the side of the control device 20.

(22) In detail the following substantial method steps are carried out: providing a monitoring voltage U.sub.M at the contacts 17 of the control device 20 for electrically tying the control lines 16 for the duration of a time interval t.sub.1, charging the energy storage 9 of the monitoring module 21 by means of the applied monitoring voltage U.sub.M for the duration of the time interval t.sub.1, switching off the monitoring voltage U.sub.M after the expiration of the time interval t.sub.1, generating a regulated voltage U.sub.0 from the energy storage 9 using a voltage regulator 8, measuring a resulting voltage value U.sub.1 at the contacts 17 using an A/D converter 2 and storing the voltage value U.sub.1 in a memory 22, activating the constant current sink 6 by means of the microcontroller 1 and impressing a current value I.sub.2 into the control lines 16, measuring a voltage value U.sub.2 using the A/D converter 2 at the contacts 17, that is generated as a result of KL5 the impressed voltage value I.sub.2, storing the voltage value U.sub.2 in the memory 22, and calculating the line resistance R.sub.L 7.

(23) Providing the monitoring voltage U.sub.M preferably takes place by switching the switching device 5.

(24) This inventive method can be carried out preferably with all development variants of the inventive device that are presented in FIGS. 1 to 4, but it is not limited to these devices.

LIST OF REFERENCE SYMBOLS

(25) 1. microcontroller 2. A/D converter 3. voltage source for generating the activation voltage U.sub.A of the actuator 10 4. voltage source for generating the monitoring voltage U.sub.M 5. switching device 6. constant current sink 7. line resistance R.sub.L 8. voltage regulator 9. energy storage 10. actuator 11. rectifier 12. terminating resistance R.sub.EOL 13. switch 14. limit-value switch 15. series resistor 16. control lines 17. contacts for connecting the control lines to the central control device 20 18. terminal contacts on the monitoring module 21 for the control lines 16 19. electrical connection points of the monitoring module 21 with the actuator 10 20. control device 21. monitoring module 22. memory 23. fire detection and/or extinguishing control panel 24. control group module 25. ring bus participant module 26. ring bus participant