DE202008012029U1 - bus system - Google Patents

Abstract

bus system comprising a control unit (1), one from the control unit (1) outgoing signal transmission device (2) and at least two, forming a series arrangement, via bus coupling points (11, 12) bus subscribers connected to the signal transmission device (2) (3, 4), characterized in that each bus subscriber (3, 4) associated with this controllable bus separation device (5, 6) is, in the activated state, a separation of the signal transmission device (2) after the Busankopplungspunkt (11, 12) of the respective bus station (3, 4).

Description

The The invention relates to a bus system comprising a control unit, an outgoing from the control unit signal transmission device and at least two, forming a series arrangement, via bus coupling points Bus subscribers connected to the signal transmission device.

bus systems for the communication of spatially distributed system components, about actuators, sensors and control devices are known. Find use Bus systems, for example in vehicles, in systems for office communication and automation technology. For the automation of the building technology installation busses used, whereby by means of a bus system household appliances, Components of an alarm system and the devices for heating buildings or air conditioning can be controlled centrally and remotely controlled.

The Control of lighting devices by means of a bus system allows a user, for example, a variety control of bulbs simultaneously and by means of a single switch operation for example, to select a programmed lighting scene, for a predetermined for a variety of lamps Brightness is set, which is a typical usage situation equivalent. Such lighting control can also be automated be made by equipped with brightness sensors Bus subscriber sensor data return to the control unit, the then, according to its programming, the building lighting automatically adjusts.

Examples for bus systems for controlling lighting equipment are the control protocol DALI (Digital Addressable Lighting Interface), preferably used for the stage lighting Control protocol DMX (Digital Multiplex) and that on the European Installation bus (EIB) based KNX standard. Each one on such Bus system connected lighting device includes in addition to the actual light source or the photometric sensor a resource with a bus coupler, through which the respective Photometric device the data exchange with the signal transmission device of the bus system and the associated digital protocol performs.

following is for the different ones connected to the bus Device uses the term "bus participant", Preferably, these are bus-compatible lighting devices. For such a bus subscriber is a separation of Power supply and the device control so that the operating state, such as the on / off state or a dimmer position, for each bus participant can be set individually.

To the It is necessary to address this to a single bus user to assign a unique address during initialization. In the simplest In case this is done by the setting of coding switches at the respective Attendees. This process may be for reasons of accessibility the coding switch or their small size be expensive. It also sets the setting of coding switches a possible source of error during system initialization represents.

Alternatively, it is possible to work with predetermined serial numbers or random addresses which, in the case of a bidirectional bus system, the bus subscriber can report to the control unit during initialization. If this option is not given, then an address input must be made directly on the control unit, which in turn creates the risk of incorrect input. As an alternative to initialization is in DE 199 09 646 A1 discloses an individual address assignment for a lighting control installation bus. In this case, each bus subscriber connected to the installation bus comprises a resource and a light source. After the connection to the (installation bus, the contact between the lamp and the equipment is temporarily disconnected.This measure recognizes the bus user for the control unit, since with a non-connected lamp, the equipment sends a message to the control unit via the bus During the initialization phase The above-described method is particularly complicated when commissioning larger, locally distributed lighting installations.

Another initialization process is through the DE 44 22 215 A1 disclosed. At the beginning of initialization, all bus subscribers have originating addresses that do not include information regarding their arrangement or grouping. These source addresses are first transmitted to the control unit in the bus system. The controller then activates each of the bus users individually with its source address. In the case of a light source provided in the bus subscriber, this activation may be a change in the illuminance, for example. At a selected bus subscriber, a monitoring device is installed which, in the event of activation, provides feedback to the control unit. In this case, the source address is replaced by an operating address from which the spatial arrangement or the classification of the bus user can be read. This procedure is then repeated for each of the other bus subscribers, ie the supervisor is then re-placed each time. Accordingly, this initialization method is particularly suitable for spatially extended installation bus systems in the implementation consuming.

An alternative to the assignment of individual addresses during initialization is when a bus station can only be addressed by its physical positioning in the bus system. This is given for the special case of a bus system in daisy-chain arrangement, in which the signal transmission device is designed so that the bus users are connected in a series arrangement. This is understood to mean a special bus topology for which each bus subscriber comprises a receiver and a transmitter. The receiver receives the data stream of the signal transmission device, processes it, possibly the data packets are modified or regrouped before they are in turn forwarded via the transmitter to the subsequent bus subscriber. Accordingly, the data stream passes through each bus subscriber in the series arrangement successively. Therefore, it is possible to uniquely identify and select each individual bus subscriber based on its position within the series arrangement. A bus system with the above-described series arrangement is, for example, in EP 1 530 108 B1 disclosed. A disadvantage of a bus system with daisy-chain arrangement is that in the event of failure of a single bus subscriber, the bus subscribers following in the series arrangement fail due to the separation in the bus for lack of controllability.

Of the The invention is therefore based on the object to propose bus system, with the automatic address assignment, the physical arrangement the bus participant reflects, is feasible. For Normal operation should occur when an error occurs in one of the Bus participants communicate via the bus with the remaining ones Participants should not be disturbed.

These The object is achieved by a bus system solved with the features of claim 1.

The Method for assigning addresses to the bus participants during initialization is based on the idea that all initially physical connected to the signal transmission device of the bus system Bus participants in the first step up to the control unit in the arrangement closest bus subscriber be separated from the data flow on the bus by at least the bus device closest to the controller a separation of the signal transmission device made becomes. This bus participant then receives a first address assigned. Subsequently, the connection of the in the Arrangement of the row second bus subscriber and an address assignment for this, whereby the successive connection of the bus participants and the respective address assignment until complete Initialization continues.

to Determining a sequence of bus subscribers is of a linear form Bus topology. More complex, in particular branched bus topologies, can be initialized accordingly become, by the address distribution in each case strandwise takes place and at a branch each with an addition characterizing the branching the address sequence is generated or consecutively numbered the previously treated sub-branches by means of an offset be taken into account. The individual strands become too separated or switched on relay by means of this purpose.

to Execution of the initialization is preferred for each bus subscriber associated with a bus disconnect device controllable by that subscriber is and the one separation, d. H. a conclusion of the signal transmission device below to the bus connection point of the respective bus participant allows. Here, under the expression "following" understood that at an executed separation means a bus device of the controlling this bus subscribers continue with the control unit of the bus system via the signal transmission device can communicate while in the physical arrangement immediately following bus subscribers from the communication on the Bus is cut off.

Starting from the device described above, the following method sequence for the address assignment during the initialization of the bus system is possible:
Before the initialization with the assignment of the individual addresses, the installation of the components of the bus system, including the control unit, the signal transmission device emanating therefrom and the bus subscriber coupled thereto, are to be executed.

In the first method step of the initialization, the shortening of the bus system to only one bus subscriber takes place, namely to those subscriber who has along the line of the signal transmission device a bus connection point which is closest to the control unit. This limitation of the bus system is brought about by the fact that at least the bus subscriber closest to the control unit activates its bus disconnection device and thus effects termination of the signal transmission device before the bus connection point of the subsequent bus subscriber. In the simplest case, this is achieved by activating the bus disconnection device of all bus subscribers. There are different embodiments for this:
The activated bus disconnect device can be installed as an installati preset and activated, for example, by means of a reset. In this case, the signal transmission device is interrupted from the beginning to each bus subscriber. A design alternative is to assign the same standard address to each bus user for the initial installation. For initialization, the control unit will then address all bus subscribers by means of the standard address and transmit to them the command for activating the bus disconnect device. As a consequence, the separation of the signal transmission device presupposed for the second method step arises at least after the bus subscriber closest to the control unit.

In a second step of the initialization becomes the only one the signal transmission device addressable bus subscribers an individual address transmitted. Since it is in terms of Bus coupling point to the closest to the control unit Bus subscriber acts, can be used as an address encoding which reflects the physical sequence. Accordingly, can for the closest to the control unit Bus subscribers will be assigned an address containing the item number 1 processed. The position number 0 can then be bidirectional Be provided bus systems for addressing the controller.

In a third, subsequent process step is the newly addressed Bus participants instructed him assigned Bustrennvonrichtung to disable. This prolongs the signal transmission device to the next bus subscriber, whose bus disconnection device is active again or is set active, so that then the new termination point of the signal transmission device sets.

the the following bus subscriber is next to assign an individual address. This can easily be done can be achieved if the bus users before the address assignment initially have a programmed default address. A message provided with this default address as a signal address is then exclusively from the previously not individually addressed Bus participants receive, as the previous bus participants already allocated from the default address different individual addresses were. This message then contains the individual Address, preferably one dependent on the initialization order Address. The third method step set out above then becomes successively repeated until the last bus participant of the signal transmission device an individual address received, d. H. the fixed termination point of the strand-shaped signal transmission device is reached.

According to one advantageous embodiment, the bus system is bidirectional. This makes it possible to acknowledge the bus subscriber to return to the controller, for the case that the command to set a particular individual Address or to open the associated bus separator Will be received. Is such a multimaster capability for a bus system not present, it is preferred that used at initialization Send commands repeatedly and thus redundantly over the bus.

The invention will be described below with reference to an embodiment with reference to the attached 1 described. 1 shows schematically simplified a bus system according to the invention, comprising a control unit 1 , a signal transmission device 2 , a first bus participant 3 with a bus connection point 11 at the signal transmission device 2 and a second bus subscriber having a second bus docking point 12 , As shown, the first bus connection point is located 11 for the first bus participant 3 with respect to the controller 1 before the second bus connection point 12 for the second bus participant 4 , For the present embodiment, the first bus subscriber 3 the control unit 1 nearest bus subscribers and the second bus subscriber 4 Follows this immediately after and thus forms the second closest bus subscribers.

Furthermore, for the schematically simplified illustration in FIG 1 on the reproduction of supply lines for supplying the operating voltage to the bus subscriber 3 . 4 waived.

The first bus participant 3 is a first bus separator 5 assigned by means of a first actuating device 7 can be activated and deactivated. When activated, the first bus disconnect device cuts through 5 the bus after the first bus connection point 11 of the first bus participant 3 , wherein this separation before the Busankopplungspunkt of the subsequent bus device in the arrangement 4 done, in 1 this is the second bus connection point 12 for the second bus participant 4 ,

According to one In the first embodiment, a bus separation device comprises a monostable one Relay, preferably using an elastic element for it is that at a voltage drop at the associated actuator the relay falls back to a position at the signal transmission device is released, d. H. in case of error, it is ensured that the bus separation device is deactivated in order to avoid unwanted problems in the event of a bus node failure To interrupt the signal transmission device. Alternatively, the bus isolation device comprises electronic switches.

In addition, the bus separation device is corresponding to the design of the signal transmission device 2 trained for the in 1 2-wire arrangement shown are provided according to two switching contacts for the individual wires. For a large number of wires, in particular in the case of a parallel bus system, these are assigned a corresponding number of switches and possibly further monitoring devices which ensure that for a deactivated state all signal channels of the signal transmission device can transmit a signal and correspondingly disable all channels in the activated state.

Preferably, the bus separation device is part of the bus coupling unit, not shown in detail, and thus part of the equipment for the respective bus subscriber. These also include a termination network. Accordingly, in 1 a first termination network 9 for the first bus separation device 5 and a second termination network 10 for the second bus device 6 shown. These termination networks are used for interference-proof temporary termination of the signal transmission device 2 in the case of an activated bus separation device during the initialization and thus to secure the data transfer via the bus. In the simplest case, for the in 1 sketched 2-wire bus used as a termination network a suitable termination resistor.

The signal transmission device 2 can be configured differently, the execution basically depends on whether the bus system is designed as a parallel bus or as a serial bus. From the inven tion both bus variants are detected, in the first case, the signal transmission device 2 has a plurality of individual lines, which serve as data lines, address lines or control lines. For a serial bus system, which transmits the messages bit-serially over a common transmission medium, the number of lines can be correspondingly reduced.

Im in 1 In the embodiment shown, a 2-wire technique is used by way of example, with which an RS485 bus with duplex capability, that is to say the capability for bidirectional operation, can be realized. Due to the 2-wire technology, the RS485 bus is only half duplex capable, so that only the control unit or only one of the bus users can send in one time window. The RS485 standard uses a cable pair, which is usually designed as a twisted pair cable, a non-inverted signal line A and an inverted signal line B serially transmits data without mandatory ground reference and evaluated by a received bus device, the voltage difference of the two lines as a signal becomes. Of course, other embodiments of the bus system and thus the signal transmission device 2 conceivable for carrying out the invention.

For each part of the bus system for which an automatic individual address assignment takes place with the method during the initialization, there must be a line-shaped or strand-shaped bus topology, so that a successive sequence of the bus users along the signal transmission device 2 is present and thus an order determination of the bus coupling points of the bus subscriber is executable. However, with the method it is also possible to initialize another bus topology by performing the initialization method string by string; accordingly, the individual fingers can be processed sequentially in a star-shaped bus topology or, in the case of branching points, first a first branch and then a second branch etc. are processed. The individual strings are switched on or off for this purpose by means of relays. In the case of multiple branches, the establishment of an execution algorithm may successively initialize the entire branch structure by successively traversing individual branches originating from a particular branch and using a structural counter that takes into account the count from a previously processed branch branch for a subsequently processed one.

Hereinafter, an advantageous embodiment of the method based on a single control unit 1 outgoing line-shaped signal transmission device 2 accordingly 1 explained. According to an advantageous embodiment, a bidirectional transmission is assumed, so that the bus system is multi-master capable and thus the individual bus users feedback to the control unit 1 can send.

First, for each bus participant 3 . 4 the bus separation device 5 . 6 activated and thus after each of the assigned bus coupling points 11 . 12 a disconnection on the bus, ie an interruption of the signal transmission device 2 , performed. Preference is given to a basic setting, which is present for example after a reset, for which the actuating device generates an active position on the bus separation device and thus the signal transmission device is separated according to standard after each individual bus subscriber before the assignment of individual addresses.

Furthermore, the individual bus subscribers are set to the same default address at the beginning of the initialization procedure. This can be set in the delivery state or can be done later via a command to all bus users. AUSS In addition, the controller first sends to the default address at least once, and preferably repeatedly requests a command to activate the bus disconnect device to safely exclude the presence of inactivated bus disconnect devices. After that, the situation is that of the control unit 1 via the signal transmission device 2 only the first bus participant 3 can be addressed. Accordingly, an individual address is transmitted as the destination address with the standard address and the structure counter value in this 1 built-in. The reception of the individual address is made by the first bus user 3 by a feedback to the control unit 1 acknowledged. If this acknowledgment is outstanding, the addressing message is sent by the control unit 1 sent again. The acknowledgment of the respective bus user can be done by sending device-specific data. This can also be done later. Subsequently, the structure counter is incremented. In this way, not only an automatic and automatic address assignment for the individual bus participants but also the control unit side, an automatic detection of the number and type of devices connected to the signal transmission device.

After receipt of the acknowledgment, another control signal is issued by the control unit 1 to the newly set individual address with the request to the newly addressed bus subscriber to disable the bus disconnection device. Accordingly, the first bus subscriber closes 3 the communication link on the signal transmission device 2 so that now the bus or the signal transmission device 2 to the second bus participant 4 enough.

Next, for security reasons, the request to activate the bus disconnect device is sent to the standard address again. In the case that this for the second bus participant 4 is not activated, a corresponding activation via the second actuator 8th with effect on the second bus separator 6 respectively. With a certain time offset, an individual address is then transmitted to the standard address as signal address with the structure counter. This will only be the second bus participant 4 addressed. Corresponding to the address setting for the first bus subscriber 3 then the controller waits 1 the acknowledgment of this address setting.

Thereupon, the second bus subscriber which can now be addressed with the new, individual address will become 4 prompted his assigned second bus stop device 6 to disable, so that the subsequent third bus subscriber can be addressed - this is not in detail 1 shown. Accordingly, the initialization process of the address assignment is repeated successively until all the bus users connected to the bus are corresponding to their sequence along the signal transmission device 2 have received individual addresses. By counting the addresses assigned during the initialization process, the bus subscribers participating in the bus system are simultaneously counted.

1

control unit

2

Signal transmission means

3

first bus device

4

second bus device

5

first Bustrenneinrichtung

6

second Bustrenneinrichtung

7

first actuator

8th

second actuator

9

first Termination network

10

second Termination network

A

non-inverted signal line

B

inverted signal line

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19909646 A1 [0007]
• - DE 4422215 A1 [0008]
• - EP 1530108 B1 [0009]

Claims (5)

Bus system comprising a control unit ( 1 ), one from the control unit ( 1 ) outgoing signal transmission device ( 2 ) and at least two, forming a series arrangement, via bus coupling points ( 11 . 12 ) with the signal transmission device ( 2 ) connected bus subscribers ( 3 . 4 ), characterized in that each bus subscriber ( 3 . 4 ) a controllable by this Bustrenneinrichtung ( 5 . 6 ) is assigned, which in the activated state, a separation of the signal transmission device ( 2 ) after the bus connection point ( 11 . 12 ) of the respective bus subscriber ( 3 . 4 ). Bus system according to claim 1, characterized in that the bus separation device ( 5 . 6 ) a termination network ( 9 . 10 ), in particular designed as a terminating resistor is assigned. Bus system according to one of claims 1 or 2, characterized in that the bus separation device ( 5 . 6 ) comprises a relay or an electronic switch. Bus system according to one of claims 1 to 3, characterized in that the bus separation device ( 5 . 6 ) by means of an actuating device ( 7 . 8th ) is activated and deactivated to the respective bus user ( 3 . 4 ) assigned. Bus system according to claim 4, characterized in that the actuating device ( 7 . 8th ) an electromagnetic or optical signal for activating and deactivating the bus separation device ( 5 . 6 ) used.