[0001] The present invention is directed to a bus system and to a method for operating such
a bus system.
[0002] Bus systems are used in fire detection and alarming installations in buildings, where
a two-wired bus is used to supply power and communication to a plurality of bus devices
connected in parallel to each other between two of the bus lines.
[0003] It is well-known to form these bus lines into a loop starting and ending at a central
control unit. Such a bus system is known for example from
DE 102010047220.
[0004] If a short circuit arises along a bus line or in a bus device, in case of forming
the bus lines into a loop it is possible to isolate a short circuit and to operate
the system now as two branch lines, each starting at the central control unit and
ending immediately before the short circuit. In this way, it is possible to preserve
the operability of the bus system to a large extent.
[0005] Usually, the bus is divided by a plurality of switching elements or interrupters,
which might be associated with the bus devices, so as to interrupt or connect a respective
bus line. For example, a bus device might have for two switching elements, one on
an input side and the other on an output side.
[0006] In operation, when a short circuit occurs along a bus line, the supply voltage at
the bus drops remarkably and in consequence all switching elements open.
[0007] Subsequently, the central control unit restarts the bus system by applying the supply
voltage to the bus line. The first switching element, which is in an open state, will
detect the supply voltage and close the switches so as to connect with the bus line.
Subsequently, the second switching element will detect the supply voltage and will
change in the closed state as well. This process goes on until reaching the short
circuit. That is, when closing the switching element immediately before the short
circuit, the drop of the voltage will be recognized, and the switching element will
open again.
[0008] Subsequently, the central control unit will start to apply the supply voltage to
the other branch line that is to other end of the former loop of bus lines and one
switching element after the other will close until reaching the short circuit. When
closing the switching element immediately before the short circuit, the associated
bus device will detect the drop in the voltage and will open this switching element
again. At the end, the system will be implemented as two separated branch lines, each
extending from the central control unit to the switching element immediately before
the short circuit.
[0009] One drawback of this configuration is that it might take a long time to restart this
system after a short circuit.
[0010] In modern fire detector systems implementing this kind of bus configuration some
of the bus devices have large capacities, and it might take a long time after closing
one switching element before the supply voltage applies to the next switching element
with a necessary level to close the next switching element. The same holds true for
voice-operated alarm devices.
[0011] EP0532787 A1 discloses a bus system comprising tow bus lines formed as respective loops, a plurality
of bus devices connected in parallel between the two bus lines and distributed along
the bus lines, a central control unit and a switching element. The switching element
is provided at the middle of the bus lines and can be controlled by the central control
unit, so that the bus system can be operated as a closed loop bus or as two separate
systems.
[0012] The present invention intends to solve this problem.
[0013] The above object is achieved by a method according to claim 1, by a bus system according
to claim 6, and a computer program according to claim 9. The dependent claims are
directed to different advantageous aspects of the invention.
[0014] According to the present invention there is provided a method for operating a bus
system. The bus system comprises at least two bus lines formed as respective loops,
a plurality of switching elements connected in series so as to divide one of the bus
lines in a plurality of sections, a central control unit connected with the ends of
the bus lines and a plurality of bus devices connected in parallel between the two
bus lines and distributed along the bus lines, so that a bus device is interposed
between two consecutive switching elements.
[0015] According to the invention the method comprises the steps of:
- (a) applying a supply voltage to both ends of the bus lines starting from the central
processing unit;
- (b) closing the switching elements upon reception of the supply voltage, so as to
connect the subsequent respective sections of the bus including the bus devices from
both ends;
- (c) monitoring the bus lines in order to detect a first short circuit;
if no first short circuit is detected, repeating steps (a), (b) and (c) until all
switching elements are closed or until a first short circuit is detected.
[0016] If a first short circuit is detected, the method comprises:
(d) opening the two switching elements closed immediately before detecting the first
short circuit;
(e) closing again one of the switching elements opened in step (d);
(f) monitoring the bus lines in order to detect a second short circuit.
[0017] If a second short circuit is detected:
(g) opening the switching element closed immediately before detecting the second short
circuit and keeping this switching element open and
(h) closing again the other switching element opened in step (d).
[0018] The invention provides the benefit that the system is started from both ends of the
bus lines simultaneously, so that the time for connecting all bus devices is reduced
to a half.
[0019] However, since in this case, when two switching elements - one at each side - close
within a short time period and one of them is adjacent to a short circuit, it is not
easy to discriminate which of the switching elements closed in the last step is adjacent
to the short circuit. The invention therefore proposes the above method, to open again
the last two switching elements closed immediately before detecting the short circuit,
and then, with different time periods respectively time delays, closing these switching
elements again, so as to surely recognize which of these switching elements is adjacent
to the short circuit.
[0020] In this way, the reliable and fast recovery of the alarm system in case of a short
circuit is possible.
[0021] According to a further advantageous aspect of the invention the method comprises
an initialization step for setting the time periods for closing each switching element
again after the detection of a first short circuit.
[0022] Basically, there are various different forms to set these time periods or delay times.
[0023] One advantageous form to set the time periods might be a dedicated time period writing
command from the central control unit, which can be used to write a corresponding
individual delay time into an internal memory of each switching element or an associated
bus device.
[0024] A further advantageous system might be to allow the central control unit to run a
dedicated initialization sequence that can be used the first time the system is started.
In this case, the central control unit would apply the supply voltage only from one
end of the bus lines, so that all switching elements are closed one after the other
in series. At that occasion the switching elements can recognize the direction from
which the voltage is applied, and can store a first delay time for this event. Additionally,
the switching elements can store a second delay time, which can be set at a different
value, for the case that a supply voltage would be applied from the other direction.
[0025] Accordingly, after opening the switching elements upon detection of a first short
circuit in step (d), the closing of the switching elements in steps (e) and (h) will
be done at a different timings so that it can be identified which one of these switching
elements is adjacent to the short circuit.
[0026] As a further alternative it might be possible to construct the switching elements
by hardware so that they have a dedicated direction of connection with the bus.
[0027] Finally it is possible to set individual delay times at random when manufacturing
the switching elements. In this way the probability that the two switching elements
will close again at the same time can be reduced.
[0028] As a further advantageous aspect of the invention - in a bus system offering an information
exchange capability between the switches, bus devices and central control unit, it
is possible to register the bus address of the last bus device before the switching
elements which remain open. This information can be stored in a memory of the central
processing unit and can be used to issue a notification message helping to locate
the short circuit.
[0029] According to the invention, furthermore, there is provided a corresponding bus system
which is configured to operate according to the above-described method.
[0030] According to another aspect of the invention a bus device and one or two switching
elements are grouped together at the bus unit, which is individually addressable by
the central control unit.
[0031] A bus device of the invention can be any one of: an audio alarm device, an optical
alarm device, a fire detector, a burglar detector and a building service management
device.
[0032] Furthermore, according to the invention a central control unit is provided, which
is specially configured to be used in a method as described above.
[0033] Furthermore, the invention is directed to a switching element for a bus system.
[0034] Finally, the invention is directed to a computer program that, when loaded in the
internal memory of a processor of a central control unit of a bus system will cause
the bus system to perform the above-described method.
[0035] In the following, preferred embodiments of the invention will be described based
on the enclosed Figures, showing further advantageous modifications of the invention.
- Fig. 1:
- the basic design of a bus system;
- Fig. 2:
- a block diagram of a switching element used in the bus system of Fig. 1;
- Fig. 3:
- a flowchart of the initialization step in a preferred embodiment, and
- Fig. 4:
- a flowchart of the program execution in a microprocessor of a switching element according
to Fig. 2;.
[0036] As Fig. 1 shows, a central control unit containing the inherently-known components,
e.g. for public address systems, has a connection R for the start of a two-wired ring
line and a connection B for the end of this ring line. The wires of the ring line
are looped through switching elements 5
1, 5
2 ... 5
n. In practice, the ring line may comprise 60 or more switching elements. Loudspeakers
- not shown here - are connected to the wires of the ring line in the switching elements
of the public address system. Loudspeakers is only one example of a bus device which
might be used in connection with the bus system. Other bus devices might include audio
alarm devices, optical alarm devices, fire detectors, burglar detectors or other kind
of building service management devices.
[0037] Furthermore, although in the embodiment of Fig. 1 loudspeakers are shown to be connected
with the switching element, it is possible to connect the bus devices, including loudspeakers
to the line sections between the switching elements directly.
[0038] Usually, such systems involve the audio signals being supplied at up to 100 Vrms.
In addition, the AC supply voltage supplied is a signal at 22 kHz and with an amplitude
of 50 V, for example.
[0039] Between the central control unit 7 and switching elements 5
1 to 5
n and between switching elements 5
1 to 5
n themselves, there is no need to provide separate communication links, unlike in the
case of some alarm systems, e.g. fire alarm systems, which are designed using ring
bus technology and have, on the ring bus, switching elements which communicate digitally
at least with a central control unit and are controlled by a dedicated bus communication
protocol. However, communication between the bus devices, switching elements and central
control unit is not excluded and can be advantageously used in many cases.
[0040] Fig. 2 shows a simplified block diagram of a switching element 5
1, drawn with one pole. The contact terminal 5A has the incoming ring line 1 connected
to it, and the contact terminal 5B has the outgoing ring line connected to it. Two
switches S1 and S2 are connected in series in a wire of the ring line. The ring line
is looped through contact terminal 5A to contact terminal 5B. Between S1 and S2 there
is a contact terminal 5C for connecting a loudspeaker 9
2 as a bus device 9. Further loudspeakers 9
1 to 9
n may be connected to the ring line outside the switching elements.
[0041] The switches S1 and S2 are in this case designed as relays which are not shown here
in any more detail, both on account of the high audio voltages and on account of the
high audio currents. The relays and hence the switches S1 and S2 are controlled by
a microcontroller, specifically on the basis of whether there is an adequate voltage
level on the input and/or the output, to be more precise, whether a prescribed supply
voltage level is exceeded or undershot. The separate voltage checking circuits, respectively
the short circuit detection means, which are required for this purpose are known and
therefore not shown in more detail.
[0042] The microcontroller receives its operating voltage from a power supply unit. The
power supply unit can be any of an external power supply unit or an internal power
supply unit like a large capacitor or a secondary cell, which might be charged from
the AC supply voltage via rectifiers during normal operation.
[0043] Fig. 3 shows an example of an initialization routine that can be used when setting
up the bus system of the invention for the first time.
[0044] In the following, the routine of Fig. 3 is described as one example for initialization
of the bus system.
[0045] In an initial state of the bus system, all switches of all switching elements 5
1 to 5
n are in an open state, that is, so that the bus lines are interrupted at any switching
element.
[0046] At the beginning, the central control unit 7 is advised to apply the supply voltage
to the terminal A. The terminal B does not receive the supply voltage from the central
control unit 7.
[0047] In reaction to applying the supply voltage to terminal A, the first switching element
5
1 of the series of switching elements 5
1 to 5
n connected along the bus will close the switch S1 and, once the supply voltage reaches
the second switch S2, the second switch will close as well.
[0048] The microcontroller of the switching element 5
1 will memorize the switching order of switches S1 and S2. In this way, the switching
element 5
1 knows in which direction of the bus line the terminal A and the terminal B respectively
are located.
[0049] After closing the switches S1 and S2 of the first switching element 5
1, the supply voltage applies to the switching element 5
2 and again, the first switching element S1 and S2 of this switching element 5
2 will close in the order described in connection with the first switching element
5
1.
[0050] The initialization process will continue until closing the switches S1 and S2 of
the last switching element 5
n.
[0051] After that, the bus system is in a condition to operate normally.
[0052] Based on the information memorized in the memory element of the individual switching
elements 5
1 to 5
n regarding the arrangement of the switches S1 and S2 with respect to the terminals
A and B, the switching elements 5
1 to 5
n are designed to allocate delay times to the switches S1 or S2 of each switching element
5
1 to 5
n, depending on the orientation of the switches S1 and S2 with respect to the terminal
A or terminal B.
[0053] For example, a delay time of 0.1 s can be assigned to the switches S1 and a delay
time of 0,5 s can be assigned to the switch S2.
[0054] If during the operation of the bus system a short circuit occurs along the bus or
at one of the bus devices, the supply voltage on the bus line will drop immediately.
As a consequence, all switches S1 and S2 of all switching elements 5
1 to 5
n will open immediately to protect the bus system..
[0055] Upon detection of this event, the central control unit 7 will start a short circuit
recovery process, as shown in the flowchart of Fig. 4.
[0056] In order to accelerate the reestablishment of the operationability of the bus system
of the invention, when restarting the bus system after a short circuit, the central
control unit 7 is designed to apply the supply voltage at both terminals A and B,
simultaneously.
[0057] As a consequence, the reconnection of the bus devices 9
1 to 9
n which start from both sides of the loop and consequently, the time needed to reconnect
the bus devices will be reduced, in best case only half of the time will be needed
to reconnect all the bus devices.
[0058] However, when the connection process continues, as shown in Fig. 4, so as to reach
a location of the short circuit, upon closing switches S1 or S2 of a switching element
5
x, immediately adjacent to the location of the short circuit, the voltage on the supply
line will drop again.
[0059] To cope with this event the switching elements 5
1 to 5
n are specially configured. When closing the switches S1 and S2 the microcontroller
of the respective switching element 5X runs a short circuit monitoring routine for
a predetermined time and monitors the voltage at the bus. During this time a dedicated
threshold value can be applied to discriminate between the normal operation and a
short circuit. If, during this predetermined time the voltage at the bus line drops
below the above threshold, the switching element 5
x opens the switches again, since it assumes that a short circuit has occurred.
[0060] The other switching elements 5
1 to 5
x-1 and 5n to 5
n-x+1 will keep their switches closed, since they are not operating in the short circuit
monitoring routine.
[0061] However, the switching element 5
n-x, which is supplied with the supply voltage from the other terminal as the switching
element 5
x and which had turned in the closed state at about the same time as the switching
element 5
x will be in the short circuit monitoring routine as well and will open the associated
switches S1 and S2.
[0062] In a subsequent step, the central control unit will continue to apply the supply
voltage from both terminals A and B. The switches of the two switching elements 5x
and 5
n-x, would therefore close again. However, at time the delay time previously obtained
in the initialization step will be applied, so that the switches of the switching
elements 5
x and that of the switches 5
n-x will close at different timings so as to avoid that these switching elements run
the short circuit monitoring routine at the same time again. That is, e.g. the switching
element 5
n-x will wait a time sufficiently large compared to the predetermined time during which
the switching element 5
x runs the short circuit monitoring routine, before closing the switches S1 and S2
again.
[0063] If the short circuit is located on the site of the switching element 5
x the drop of the voltage will be detected again, and accordingly, the micro controller
of the switching element 5
x will know that the short circuit is immediately adjacent to the switching element
5
x. In that case, the switches of the switching element 5
x will remain open, and the setup of the loop will continue from the site of the terminal
B by closing switches of the switching element 5
n-x
[0064] The closes will continue until reaching the switching element 5
x+1. In case of a short circuit along the bus line, when closing the switches of the
switching element 5
x+1, the micro controller of this switching element 5
x+1 will detect the drop of the voltage at the bus line and open the switches S1 and
S2 immediately. After waiting the corresponding predetermined time the switching element
5
x+1 will close the switches again and will detect the short circuit a new. In consequence,
to the consecutive detection of two short circuit events the micro controller of this
switching element 5
x+1 knows, that the short circuit is immediately adjacent and will therefore open the
switches S1 and S2 and keep them open.
[0065] Therefore, the short circuit will remain isolated between the switching elements
5
x and 5
x+1, and the bus system can be operated in two branch lines.
[0066] On the other hand, if the short circuit is located adjacent to the switching element
5
n-x+1 and not immediately adjacent to the switching element 5
x, in the above process, when closing the switches of the switching element 5
x, no drop of the supply voltage on the bus line will occur, a short circuit recovery
process will continue on the line starting from the terminal A by closing the switches
of the switching element 5
x+1 thereon.
[0067] In this case the short circuit has to be located adjacent to the switching element
5
n-x+1. However, after the lapse of the delay time associated with this supply direction
or with this switching element, the switching element 5
n-x+1 will close the respective switches again and will run the short circuit monitoring
routine. The drop of the voltage at the bus line will be detected by the microcontroller
of this switching element, and due to the two consecutive detections of a short circuit,
the micro controller knows that the short circuit is located immediately adjacent
to the switching element 5
n-x+1. Therefore, it will control this switching element so as to keep the respective switch
in an open state.
[0068] It might happen, that at the time the switching element 5
n-x+1 detects this short circuit, an other switching element, e.g. 5
x+y receiving the supply voltage from the other terminal is running a short circuit monitoring
routine as well. In this case this switching element will open the respective switches
as well. However, since this was the first short circuit detection at that switching
element 5
x+y it will close the switches again after a certain delay and the reconnection of the
bus can proceed.
[0069] In this way, a fast and safe reestablishment of the operationability of the system
in large parts can be established after a short circuit.
[0070] In a preferred embodiment the micro controller of the switching elements are designed
so as to send a message including a dedicated address to the central control unit
upon closing the switches. From these messages the central control unit will know,
which switching elements are immediately adjacent to the short circuit and might display
a corresponding message. However, a skilled person will recognize that the above method
can be run on a bus system without any bidirectional communication between the switching
elements 5
1 to 5
n/bus devises 9
1 to 9
m and the central control unit 7.
[0071] According to the above-described process, the delay time is set during the initialization
step depending on the connection direction of the switching elements. Although this
is a preferred embodiment, alternative configurations might be possible. For example,
it might be possible to set an individual and different delay time for each switching
element 5
1 to 5
n by a dedicated command of the central control unit, which will apply when closing
the switching element again after detection of the first short circuit. In this way
again, it can be avoided that repeatedly switching elements close simultaneously,
which would obscure the discovery of the location of a short circuit.
[0072] As a further alternative it is possible to design the switching elements 5
1 to 5
n so as to have different connection sites, which differ in the hardware construction,
so that the delay is already built in the switching element. Although this conveys
the drawback that, when installing the bus system, the workers connecting the switching
elements 5
1 to 5
n have to take care to connect the switching elements 5
1 to 5
n in the correct orientation, it has the advantage that no initial setup procedure
is required, and therefore already at the first time of turning on the bus system
the buildup of the system can start from both terminals A and B simultaneously.
[0073] The method can be implemented e.g. by programming the micro controllers in the switching
elements 5
1 to 5
n andf the central control unit with a dedicated programming when installing an up-date
on a corresponding bus system.
[0074] The invention has been described based on a voice operated alarm system. However
the invention can advantageously be used in a bus system connection smoke detectors
or visual and/or acoustical alarm devices.
[0075] Furthermore, the switching elements 5
1 to 5
n have been described so as to comprise two switches. However, it is possible to build
each or some switching devices so as to include only one switch. In this case in the
initialization procedure of Fig. 3. The direction of the terminals A and B has to
be discriminated in a different manner, e.g. based on the voltage measurement shown
in Fig. 2. Depending on which site the voltage applies first, the micro controller
will set different delay times.
[0076] While in the present invention the micro controller of the switching devices where
used to control the respective steps, it is although possible to assign this task
to a processor in the central control unit. This processor has to be arranged and
implemented so as to monitor the voltage at the bus lines and so as to control the
switching operations of the switches in the switching elements. Although this configuration
requires a more complex communication on the bus it has the advantage that less power
is needed in the individual switching devices.
[0077] Although the present invention has been described by reference to preferred embodiments,
it is clear that the invention is not limited to these particular embodiments. It
is possible to adapt modifications and replacements. For example, it is possible to
combine the switching element and the bus devices into a single device. In that case,
the bus device will be connected between the switches S1 and S2 of a bus device, as
shown in the example of Fig. 2 with the speaker 9
2. Alternatively, switching elements 5
1 to 5
n can be provided independent of the bus devices as well.
[0078] Furthermore, it is not necessary that the bus devices are loudspeakers. As mentioned
above, other bus elements, such as fire detectors or smoke detectors or visual alarms
can be used instead.
1. Method for operating a bus system;
the bus system comprising at least two bus lines (1, 3) formed as respective loops,
a plurality of switching elements (51 to 5n) connected in series so as to divide one of the bus lines in a plurality of sections,
a central control unit (7) connected with the ends of the bus lines (1, 3), and a
plurality of bus devices (91 to 9m) connected in parallel between the two bus lines (1, 3) and distributed along the
bus lines (1, 3) so that a bus device (9y) is interposed between two consecutive switching elements (5x, 5x+1) ;
the method comprising the steps:
(a) applying a supply voltage to both ends of the bus lines (1, 3) starting from terminals
(A, B) of the central processing unit (7);
(b) closing the switching elements (51, 5n) upon reception of the supply voltage, so as to connect the subsequent respective
sections of the bus from both ends;
(c) monitoring the bus lines (1, 3) in order to detect a first short circuit;
if no first short circuit is detected repeating the steps (a), (b) and (c) until all
switching elements (51, 52, 53, 54, ..5n) are closed or until a first short circuit is detected;
if a first short circuit is detected,
(d) opening the two switching elements (5x, 5(m-x)) closed immediately before detecting the first short circuit,
(e) closing again one of the switching elements (5x) opened in step (d);
(f) monitoring the bus lines (1, 3) in order to detect a second short circuit;
if a second short circuit is detected,
(g) opening the switching element (5x) closed immediately before detecting the second short circuit and keeping this switching
element (5x) open, and
(h) closing again the other switching element (5(m-x)) opened in step (d).
2. The method of claim 1 further comprising the step:
running a short circuit monitoring routine by a switching element (51 to 5n) for a predetermined time after closing the switching element, wherein during the
short circuit monitoring routine comprises monitoring the bus line for a drop of a
voltage below a second threshold value, which is higher than a threshold value used
to monitor for a short circuit at other times.
3. The method of claim 2 wherein a difference in delay times between the closing again
of the switching elements (5x and 5y) opened in step (d) is larger than the predetermined time of the short circuit monitoring
routine.
4. The method of claim 1, 2 or 3 further comprising the step:
upon opening a switching element ((51, 5(m-1)) registering a bus addresses of a last bus devices before said switching element
(51, 5(m-1), 5o) in a memory of the central control unit (7);
issuing a notification message informing about the estimated location of the short
circuit based on this bus addresses.
5. The method of claim 1, 2, 3 or 4 further comprising an initialisation process which
is performed when setting up the bus system and which comprises the steps:
applying a supply voltage to one of the bus lines (1, 3) starting from terminals (A)
of the central processing unit (7);
closing the switching elements (51 to 5n) in series;
detecting the orientation of each switching element (51 to 5n) with regard to the terminal (A);
setting different delay times for the switching element (51 to 5n) for the case of receiving the supply voltage via the site of said terminal (A) than
for the case of receiving the supply voltage via the other site; wherein this delay
times are used to control the closing of the switching elements in steps (e) and (h).
6. Bus system configured to be operated according to the method of claims 1 to 5, the
bus system comprising:
at least two bus lines (1, 3) formed as respective loops,
a plurality of switching elements (51, 52, 53, 54, ..5n) connected in series so as to divide one of the bus lines in a plurality of sections,
a central control unit (7), and
a plurality of bus devices (91, 92, 93, 94, ...9m) connected in parallel between the two bus lines (1, 3) and distributed along the
bus lines (1, 3) so that a bus device (9y) is interposed between two consecutive switching elements (5x, 5x+1);
wherein the central control unit (7) is configured to apply a supply voltage to both
ends of the bus lines (1, 3) starting from terminals (A, B) of the central processing
unit (7) ;
the plurality of switching elements (51, 52, 53, 54, ..5n) is configured to close, upon reception of the supply voltage, so as to connect the
subsequent respective sections of the bus from both ends, to monitor the bus lines
(1, 3) in order to detect a first short circuit, to open the two switching elements
(5x, 5(m-x)) closed immediately before detecting the first short circuit, to close again one
of the switching elements (5x) just opened, to monitor the bus lines (1, 3) in order to detect a second short circuit,
to open the switching element (5x) closed immediately before detecting the second short circuit and to keep this switching
element (5x) open, and to close again the other switching element (5(m-x)) opened upon detection of the first short circuit.
7. Bus system according to claim 6, wherein
a bus device (91, 92, 93, 94, ...9m) and one or two switching elements (51, 52, 53, 54, ..5n) are grouped as a bus unit (11), which is individually addressable by the central
control unit (7).
8. The bus system according to any of claims 6 or 7, wherein
the bus devices ((9
1, 9
2, 9
3, 9
4, ...9
m) comprise at least one of:
an audio alarm device,
an optical alarm device,
a fire detector,
a bugler detector, and
a building service management device.
9. A computer program that, when loaded in the internal memory of a processor of a central
control unit and/or the switching elements of a bus system according to any of claims
6 to 8, will cause the bus system to perform the steps of the method of any of claims
1 to 5.
1. Verfahren zum Betreiben eines Bussystems, wobei
das Buchssystem umfasst: zumindest zwei Busleitungen (1,3), die als jeweilige Schleifen
ausgebildet sind, eine Mehrzahl von Schaltelementen (5
1 bis 5
n), die in Reihe geschaltet sind, um so eine der Busleitungen in eine Mehrzahl von
Abschnitten zu unterteilen, eine zentrale Steuereinheit (7), die mit den Enden der
Busleitungen (1,3) verbunden ist, und eine Mehrzahl von Busvorrichtungen (9
1 bis 9
n), die parallel zwischen den Busleitungen (1,3) geschaltet und entlang der Busleitungen
(1,3) verteilt sind, so dass die Busvorrichtung (9
y) zwischen zwei aufeinander folgenden Schaltelementen (5
x, 5
x+1) angeordnet ist,
wobei das Verfahren die Schritte umfasst:
(a) Anwenden einer Zufuhrspannung an beide Enden der Busleitungen (1,3) beginnend
von Anschlüssen (A,B) der zentralen Steuereinheit (7);
(b) Schließen der Schaltelemente (51, 5n) bei Empfang der Zufuhrspannung, um so darauffolgende jeweilige Abschnitte des Buses
von beiden Enden zu verbinden;
(c) Überwachen der Busleitung (1,3), um einen ersten Kurzschluss zu erfassen;
wenn kein erster Kurzschluss erfasst wird, Wiederholen der Schritte (a), (b) und (c)
bis alle Schaltelemente (51, 52, 53, 54 ... 5n) geschlossen sind oder bis ein erster Kurzschluss erfasst wird;
wenn ein erster Kurzschluss erfasst wird,
(d) Öffnen der zwei Schaltelemente (5x, 5m-x), die unmittelbar vor dem Erfassen des ersten Kurzschlusses geschlossen wurden,
(e) erneutes Schließen eines der Schaltelemente (5x), die im Schritt (d) geöffnet wurden;
(f) Überwachen der Busleitungen (1,3), um einen zweiten Kurzschluss zu erfassen;
wenn ein zweiter Kurzschluss erfasst wird,
(g) Öffnen des Schaltelements (5x), das unmittelbar vor dem Erfassen des zweiten Kurzschlusses geschlossen wurde und
Beibehalten des Schaltelements (5x) im offenen Zustand; und
(h) erneutes Schließen des anderen Schaltelementes (5m-x), das in Schritt (d) geöffnet wurde.
2. Verfahren nach Anspruch 1, des Weiteren mit dem Schritt:
Ausführen einer Kurzschlusserfassungsroutine durch ein Schaltelement (51 bis 5n) für eine vorgegebene Zeit nach dem Schließen des Schaltelements, wobei während der
Kurzschlusserfassungsroutine das Überwachen der Busleitung hinsichtlich eines Abfalls
der Spannung unter einem zweiten Schwellwert umfasst, der höher als ein Schwellwert
ist, der zum Überwachen eines Kurzschlusses zu anderen Zeiten verwendet wird.
3. Verfahren nach Anspruch 2, bei dem ein Unterschied in den Verzögerungszeiten zwischen
dem erneuten Schließen der Schaltelemente (5x und 5y), die im Schritt (d) geöffnet wurden, größer als die vorgegebene Zeit der Kurzschlussüberwachungsroutine
ist.
4. Verfahren nach Anspruch 1, 2 oder 3, des Weiteren mit dem Schritt:
beim Öffnen eines Schaltelements (51, 5m-1), Registrieren einer Busadresse von zumindest je einer Busvorrichtung vor dem Schaltelement
(51, 5m-1, 5o) in einem Speicher der zentralen Steuereinheit (7);
Veranlassen einer Mitteilungsnachricht, die bezüglich des abgeschätzten Ortes des
Kurzschlusses beruhend auf der Busadresse informiert.
5. Verfahren nach Anspruch 1, 2, 3 oder 4, des Weiteren mit einem Initialisierungsprozess,
der durchgeführt wird, wenn das Bussystem aufgebaut wird, und der die Schritte umfasst:
Anwenden einer Zufuhrspannung an die Busleitungen (1,3) beginnend von Anschlüssen
(A) der zentralen Steuereinheit (7) ;
Schließen der Schaltelemente (5a bis 5n) der Reihe nach;
Erfassen der Ausrichtung jedes Schaltelements (51 bis 5n) in Bezug auf den Anschluss (A);
Einstellen unterschiedlicher Zeitverzögerung für das Schaltelement (51 bis 5n) für den Fall des Empfangs der Zufuhrspannung über die Seite des Terminals (A) gegenüber
dem Fall des Empfangs der Zufuhrspannung über die andere Seite; wobei
diese Verzögerungszeiten zur Steuerung des Schließens der Schaltelemente in den Schritten
(e) und (h) verwendet werden.
6. Bussystem, das ausgestaltet ist, um entsprechend dem Verfahren der Ansprüche 1 bis
5 zu arbeiten, wobei das Bussystem umfasst:
zumindest zwei Busleitungen (1,3), die als jeweilige Schleifen ausgebildet sind,
einer Mehrzahl von Schaltelementen (51, 52, 53, 54, ... 5n), die in Reihe geschaltet sind, um eine der Busleitungen in eine Mehrzahl von Abschnitten
zu unterteilen;
eine zentrale Steuereinheit (7); und
eine Mehrzahl von Busvorrichtungen (91, 92, 93, 94, ... 9m), die parallel zwischen den Busleitungen (1,3) geschaltet und entlang der Busleitungen
(1,3) verteilt sind, so dass eine Busvorrichtung (9y) zwischen zwei aufeinanderfolgenden Umschaltelementen (5x, 5x+1) angeordnet ist;
wobei die zentrale Steuereinheit (7) ausgestaltet ist, um eine Zufuhrspannung an beide
Enden der Busleitungen (1,3) beginnend von Anschlüssen (A,B) der zentralen Steuereinheit
(7) anzulegen;
wobei die Mehrzahl Schaltelemente (51, 52, 53, 54, ...5n) ausgestaltet ist, um bei Empfang der Zufuhrspannung zu schließen, um so die darauffolgenden
jeweiligen Abschnitte des Busses von beiden Enden zu verbinden, um die Busleitungen
(1,3) zu überwachen, um einen ersten Kurzschluss zu erfassen, um die zwei Schaltelemente
(5x, 5m-x) zu öffnen, die unmittelbar vor Erfassen des ersten Kurzschlusses geschlossen wurden,
um eines der Schaltelemente (5x) erneut zu schließen, das gerade geöffnet wurde, um die Busleitung (1,3) zu überwachen,
um einen zweiten Kurzschluss zu erfassen, um das Schaltelement (5x), das unmittelbar vor Erfassen des zweiten Kurzschlusses geschlossen wurde, zu öffnen,
und dieses Schaltelement (5x) in dem offenen Zustand zu halten, und um das andere Schaltelement (5m-x) erneut zu schließen, das bei Erfassen des ersten Kurzschlusses geöffnet wurde.
7. Bussystem nach Anspruch 6, bei dem
eine Busvorrichtung (91, 92, 93, 94, ...9m) und eine oder zwei Schaltelemente (51, 52, 53, 54, ...5n) als eine Buseinheit (11) angeordnet sind, die individuell durch die zentrale Steuereinheit
(7) adressierbar ist.
8. Bussystem nach einem der Ansprüche 6 oder 7, bei dem die Busvorrichtungen (9
1, 9
2, 9
3, 9
4, ...9
m) zumindest eins von dem folgenden enthalten:
eine Audioalarmvorrichtung,
eine optische Alarmvorrichtung,
einen Branddetektor;
einen Einbruchdetektor; und
eine Gebäudedienstleitungsmanagementvorrichtung.
9. Computerprogramm, das wenn es in den internen Speicher eines Prozessors in einer zentralen
Steuereinheit und/oder der Schaltelemente eines Bussystems entsprechend einem der
Ansprüche 6-8 geladen ist das Bussystem veranlasst, um die Schritte der Verfahren
nach einem der Ansprüche 1 bis 5 auszuführen.
1. Procédé d'exploitation d'un système de bus ;
le système de bus comprenant au moins deux lignes omnibus (1, 3) sous forme de boucles
respectives, une pluralité d'éléments de commutation (5
1 à 5
n) connectés en série de façon à diviser l'une des lignes omnibus en une pluralité
de sections, une unité de commande centrale (7) connectée aux extrémités des lignes
omnibus (1, 3), et une pluralité de dispositifs de bus (9
1 à 9
m) connectés en parallèle entre les deux lignes omnibus (1, 3) et distribués le long
des lignes omnibus (1, 3) de sorte qu'un dispositif de bus (9
y) soit interposé entre deux éléments de commutation consécutifs (5
x, 5
x+1) ;
le procédé comprenant les étapes :
(a) l'application d'une tension d'alimentation aux deux extrémités des lignes omnibus
(1, 3) en partant de bornes (A, B) de l'unité de traitement centrale (7) ;
(b) la fermeture des éléments de commutation (51, 5n) lors de la réception de la tension d'alimentation, de façon à connecter les sections
respectives ultérieures du bus depuis les deux extrémités ;
(c) la surveillance des lignes omnibus (1, 3) afin de détecter un premier court-circuit
;
si aucun premier court-circuit n'est détecté, la répétition des étapes (a), (b) et
(c) jusqu'à ce que tous les éléments de commutation (51, 52, 53, 54,... 5n) soient fermés ou jusqu'à ce qu'un premier court-circuit soit détecté ;
si un premier court-circuit est détecté,
(d) l'ouverture des deux éléments de commutation (5x, 5 (m-x)) fermés immédiatement avant de détecter le premier court-circuit,
(e) la fermeture à nouveau de l'un des éléments de commutation (5x) ouverts à l'étape (d) ;
(f) la surveillance des lignes omnibus (1, 3) afin de détecter un second court-circuit
;
si un second court-circuit est détecté,
(g) l'ouverture de l'élément de commutation (5x) fermé immédiatement avant de détecter le second court-circuit et le maintien de
cet élément de commutation (5x) ouvert, et
(h) la fermeture à nouveau de l'autre élément de commutation (5(m-x)) ouvert à l'étape (d) .
2. Procédé selon la revendication 1, comprenant en outre l'étape :
l'exécution d'une routine de surveillance de court-circuit par un élément de commutation
(51 à 5n) pendant une durée prédéterminée après la fermeture de l'élément de commutation,
dans lequel la routine de surveillance de court-circuit comprend la surveillance de
la ligne omnibus à la recherche d'une chute de tension en dessous d'une seconde valeur
seuil, qui est supérieure à une valeur seuil utilisée pour surveiller un court-circuit
à d'autres instants.
3. Procédé selon la revendication 2, dans lequel une différence de temps de retard entre
la fermeture à nouveau des éléments de commutation (5x et 5y) ouverts à l'étape (d) est plus grande que la durée prédéterminée de la routine de
surveillance de court-circuit.
4. Procédé selon la revendication 1, 2 ou 3, comprenant en outre l'étape :
lors de l'ouverture d'un élément de commutation (51, 5(m-1)), l'enregistrement d'une adresse de bus d'un dernier dispositif de bus avant ledit
élément de commutation (51, 5(m-1), 5o) dans une mémoire de l'unité de commande centrale (7) ;
l'émission d'un message de notification informant de l'emplacement estimé du court-circuit
d'après cette adresse de bus.
5. Procédé selon la revendication 1, 2, 3 ou 4, comprenant en outre un processus d'initialisation
qui est réalisé lors de l'installation du système de bus et qui comprend les étapes
:
l'application d'une tension d'alimentation à l'une des lignes omnibus (1, 3) en partant
de bornes (A) de l'unité de traitement centrale (7) ;
la fermeture des éléments de commutation (51 à 5n) en série ;
la détection de l'orientation de chaque élément de commutation (51 à 5n) par rapport à la borne (A) ;
le réglage de temps de retard différents pour l'élément de commutation (51 à 5n) dans le cas d'une réception de la tension d'alimentation via le site de ladite borne
(A) de ceux dans le cas d'une réception de la tension d'alimentation via l'autre site
; dans lequel ces temps de retard sont utilisés pour commander la fermeture des éléments
de commutation aux étapes (e) et (h) .
6. Système de bus configuré pour être exploité selon le procédé des revendications 1
à 5, le système de bus comprenant :
au moins deux lignes omnibus (1, 3) sous forme de boucles respectives,
une pluralité d'éléments de commutation (51, 52, 53, 54,... 5n) connectés en série de façon à diviser l'une des lignes omnibus en une pluralité
de sections,
une unité de commande centrale (7), et
une pluralité de dispositifs de bus (91, 92, 93, 94,... 9m) connectés en parallèle entre les deux lignes omnibus (1, 3) et distribués le long
des lignes omnibus (1, 3) de sorte qu'un dispositif de bus (9y) soit interposé entre deux éléments de commutation consécutifs (5x, 5x+1) ;
dans lequel l'unité de commande centrale (7) est configurée pour appliquer une tension
d'alimentation aux deux extrémités des lignes omnibus (1, 3) en partant de bornes
(A, B) de l'unité de traitement centrale (7) ;
la pluralité d'éléments de commutation (51, 52, 53, 54,... 5n) est configurée pour se fermer, lors de la réception de la tension d'alimentation,
de façon à connecter les sections respectives ultérieures du bus depuis les deux extrémités,
pour surveiller les lignes omnibus (1, 3) afin de détecter un premier court-circuit,
pour ouvrir les deux éléments de commutation (5x, 5(m-x)) fermés immédiatement avant de détecter le premier court-circuit, pour fermer à nouveau
l'un des éléments de commutation (5x) juste ouverts, pour surveiller les lignes omnibus (1, 3) afin de détecter un second
court-circuit, pour ouvrir l'élément de commutation (5x) fermé immédiatement avant de détecter le second court-circuit et pour maintenir
cet élément de commutation (5x) ouvert, et pour fermer à nouveau l'autre élément de commutation (5(m-x)) ouvert lors de la détection du premier court-circuit.
7. Système de bus selon la revendication 6, dans lequel
un dispositif de bus (91, 92, 93, ... 9m) et un ou deux éléments de commutation (51, 52, 53, 54, ... 5n) sont regroupés en tant qu'unité de bus (11), qui est adressable individuellement
par l'unité de commande centrale (7).
8. Système de bus selon l'une quelconque des revendications 6 ou 7, dans lequel
les dispositifs de bus (9
1, 9
2, 9
3, 9
4, ... 9
m) comprennent au moins l'un parmi :
un dispositif d'alarme audio,
un dispositif d'alarme optique,
un détecteur d'incendie,
un détecteur de cambrioleur, et
un dispositif de gestion de service de bâtiment.
9. Programme d'ordinateur qui, lorsqu'il est chargé dans la mémoire interne d'un processeur
d'une unité de commande centrale et/ou éléments de commutation d'un système de bus
selon l'une quelconque des revendications 6 à 8, amèneront le système de bus à réaliser
les étapes du procédé de l'une quelconque des revendications 1 à 5.