DE4041235C1 - Double ring bus system - has two buses which normally operate in parallel or are cross-coupled for testing to identify failure - Google Patents

Abstract

The double ring bus system supports a central computer (LR) and a number of substations (UR1-UR5), with the number of substations capable of being expanded. External communication with each substation and central unit can be made by bi-directional channels (RK1, RK2). The connections are made using bus coupler modules (NUKO1, BUKO2) responding to logic modules. In a normal mode the two buses operate in parallel. In the event of a failure the bus can be switched into a cross coupled mode for testing to identify the failure. ADVANTAGE - Identification of faults and improved operation.

Description

The invention initially relates to an arrangement for signaling secure transmission of serial data between preferably two channels working secure computers with a double ring bus system, as in individual the preamble of claim 1 can be removed.

Such an arrangement has become known from DE-PS 36 28 299. There the two ring buses of the double ring bus system become parallel in normal operation through which data flows redundantly in the opposite sense, and each computer (bus participant) is with one channel (station) with one Ringbus and with the other channel with the other ringbus functionally active bus couplers connected in pairs to computer-related bus controls units are summarized. If a malfunction is detected, a Switching the double ring bus system to a multi-stage test mode with Cross-connections between the ring buses a location of the fault. There after another switchover to reserve operation takes place by adjoining Sections continuously separating the faulty section into one Single ring structure can be transferred without redundancy. With the well-known An manage the two active control stations in a two-channel system Master computer hierarchically the bus access rights of the substations of the rest Computer. Disturbances in the data flows in the ring buses during normal operation detected by the host computer, which then switches to a test mode, at which the substation computers from the host computer via their assigned bus Control units for fault location localization can be called up. After feast The location of the fault location is then a via the bus control units Switch to single ring structure.

The object of the invention is the known arrangement with regard to To optimize localization of the points of failure and with a changed assignment of the bus couplers to the ring buses the mutual improve physical and functional decoupling.

This task is according to an arrangement of the type mentioned the characterizing features of claim 1 solved. Favorable off designs and methods for operating the arrangement are the Unteran sayings removable.

With the invention, faults can be recognized, localized and more quickly be bridged. Thanks to the improved decoupling, moreover for safety-relevant communication systems, the safety certificate facilitated.  

The invention will be described in the following with the aid of schematic exemplary embodiments standing explained in more detail.

The drawing figures show:

Figure 1 shows the bus system in the "normal mode".

FIG. 2 shows the flow of data in the bus control unit of a bus device of FIG. 1;

Fig. 3, the bus system in the "test mode 1";

Fig. 4 shows the data flow in a bus control unit of a bus subscriber according to Fig. 3;

5 shows the bus system in the "test mode 2".;

Fig. 6 shows the flow of data in a bus control unit of a bus member taker of Fig. 5;

Fig. 7, the bus system is in "standby mode 1" with data traffic of the computer channels RK 1 with each other;

Fig. 8 is the corresponding flow of data in the bus control unit of a bus subscriber BSE in BSE mode "loop 1/2" in FIG. 7;

Fig. 9 shows the transmission system in the operating mode "Reservebe 2" with data traffic of the computer channel RK 2 ;

FIG. 10 is the corresponding flow of data in the bus control unit of a bus subscriber in BSE mode "2/1 loop" of Fig. 7;

Fig. 11 to 20 realizable using logical switch data flows within the bus couplers of slave stations and master station in different operation modes.

The basic functioning of a communication system controlled centrally by a master computer LR 5 with substation computers UR 1 to UR 5 is shown in FIG. 1. The number of substation computers is an example and can be expanded. However, the number of participants is practically limited by various factors such as the properties of the selected transmission protocol, the required maximum telegram runtime or the total availability to be achieved. The function of the host computer can either be permanently assigned to a specific bus subscriber via initialization or alternatively or cyclically assigned after the expiry of specified time intervals, the duration of which must meet the operational requirements. Both the master computer LR and the substation computers UR 1 to UR 5 are two-channel computers; each channel is considered a station (control station LSt or substation USt). The channels are each labeled RK 1 and RK 2 and each have send and receive inputs that are marked by arrows (incoming arrow = receive; outgoing arrow = broadcast). The two ring buses are labeled BUS 1 and BUS 2 . In the "normal operation" operating mode here, the two ring buses are acted upon for maximum availability in duplex operation and the messages flow through them unidirectionally independently of one another in the opposite sense. Bus couplers BUKO 1 and BUKO 2 are permanently assigned to each of the two ring buses BUS 1 and BUS 2 , of which two such bus couplers BUKO 1 and BUKO 2 each have a logical bus control unit BSE for each computer, both for master computer LR and for substation computer UR, form. For example, all BUKO 7 bus couplers are each assigned to ring bus 7 and all BUKO 2 bus couplers are each assigned to ring bus 2 . In normal operation, each computer channel RK 7 and RK 2 of a computer is assigned to one of the buses on the transmitting and receiving sides and is coupled to the bus system in terms of transmission and reception via technically identical interfaces on the bus coupler. That means computer channel RK 7 here on BUS 7 and computer channel RK 2 on BUS 2 . This principle applies to both the master computer LR and the substation computer UR. While the ring buses are interconnected in the bus couplers of the substation computers, they are interrupted in the bus couplers of the master computer LR.

In FIG. 2, the flow of data within a bus control unit BSE is further represented in more detail of a substation computer UR. One recognizes the paired bus couplers BUKO 7 and BUKO 2 , which are already indicated in FIG. 7. Each bus coupler has a bus interface BS on the input side and a further bus interface BS 'on the output side for coupling the bus, a computer interface RS for coupling to the respective computer channel and a connection interface VS for the mutual paired coupling of the bus couplers.

Thanks to the redundant cable routing with two transmission lines and the various operating modes of the active bus to be described coupler the high fault tolerance of the bus system is achieved. The Partial or total failure of a single component never leads to a total failure of the bus system, but is limited to the element affected by the failure, because if one connected fails Station or the failure of a bus coupler a reconfiguration of the Bus system is carried out.

For the ring buses, optical waveguides and / or copper cables can advantageously be used as the data transport medium. Generation and implementation as well as the time and amplitude regeneration of the signals for the switched-on computer unit is carried out by the active bus couplers BUKO 7 and BUKO 2 , two of which are used as coupling links between the bus system and the respective two-channel computers.

For a bus access, the substations must be called up by the control station, they cannot access on their own. Both computer channels RK 1 and RK 2 can then access the two buses BUS 1 and BUS 2 of the parallel redundant bus system at the same time if they want to send data to the bus as authorized stations. The two ring buses are separated in the master computer LR. This prevents the endless circulation of signals. The active host computer LR controls the entire transmission system in addition to regulating the bus access right.

On the circuits in the bus control units BSE (2 bus couplers each) otherwise received later.

In FIGS. 3 and 5 is set to the "Testbestbetrieb" (bus 1 and 2) a decreased. The test operation is carried out in two steps, bus test 1 and bus test 2 . It is used to localize a fault location. To do this, the bus control units BSE are switched over by the host computer. Only computer channel RK 1 is used for bus test 1 (cf. FIG. 3). The master computer LR is closed on the transmitter side at BUS 1 and on the receiver side at BUS 2 . The substations are on the receiver side at BUS 1 and on the transmitter side at BUS 2 . The latter is initiated by the control station via a control telegram to all accessible substations. The control station then calls all substations from UR 1 to UR 5 via computer channel RK 1 . All substations answer; the fault point X, however, means that only the responses of the substations USt from UR 2 and UR 1 can be received. This is registered by the control station. Then the switch is switched over again for bus test 2 (cf. FIG. 5). The master computer LR is connected on the transmitter side to BUS 2 and on the receiver side to BUS 1 . The substations are connected to BUS 1 on the transmitter side and to BUS 2 on the receiver side. The stations of UR 1 and UR 2 do not switch over here, however, because they do not reach a corresponding request telegram. If all substations from UR 1 to UR 5 are subsequently called by the control station, then only the substations from UR 3 to UR 5 can respond due to fault point X here. This is also registered by the control station and fault point X is located between UR 2 and UR 3 .

It is irrelevant whether the interruption is in one or both ring buses, whether it only occurs between the stations (as in FIGS. 3 and 5) or whether a complete substation computer is affected. In the event of several interruptions or failures, the last station that can still be reached is determined on the respective bus.

FIGS. 4 and 6 reflect the relevant data flows in the Buskopp learning of the bus control units of the substation computer to FIGS. 3 and 5 again.

After the location of a failure that has occurred has been localized using the bus test, BSE loops are set in the bus control units adjacent to the failure point. The system switches to standby mode, whereby fault point X is excluded. Vergleichlich of Fig. 7 and 9 to the bus control unit BSE the sturgeon point X lying adjacent substation computer UR 2 by a cross-link all data from BUS 1 (inclusive of the substation computer (UR (directed to the BUS 2 2) BSE mode Loop 7/2) In the bus control unit BSE of the substation computer UR 3 adjacent to fault location X, the data traffic is redirected from BUS 2 to BUS 1 (BSE mode loop 2/7). A single large ring bus is created (Horseshoe shape).

Fig. 7 shows the first phase of the backup operation (reserve operation 1). Only computer channel RK 1 of master computer LR has the control function (active bus access right, control station), the other computer channel RK 2 works like a substation (passive bus access right). The master computer LR sends and receives via the ring bus BUS 7 . The BUS 7 is opened in the control station via the BUKO 7 bus coupler, the BUKO 2 bus coupler is switched to continuity. Only data traffic between all interfaces to the computer channel RK 1 is processed. After a defined time, the bus control unit of the master computer LR is switched to the second phase of the reserve mode (reserve mode 2), in which the other computer channel RK 2 now takes over the control function (see FIG. 9).

The computer channel RK 7 is now initialized as a substation. The bus interruption of BUS 7 in the former control station has been withdrawn and the associated BUKO 7 bus coupler has been switched to continuity. Sending and receiving is via BUS 2 , for this purpose the bus in the new control station is opened via bus coupler BUKO 2 . The data traffic between all interfaces to the computer channel RK 2 is now processed. After a defined time, the bus control unit of the master computer LR switches back to the first phase of the reserve mode (reserve mode 1).

To give the 8 and 10 -. In addition to Figures 7 and 9 -. The data flows in the bus couplers of the bus subscribers more accurately, the bus control units BSE work in the BSE mode loop 1/2, or 2/1.

In the other Figs. 11 to 20 but schemati sierender block diagram is provided of a single bus coupler (as part of a bus control unit) the different data flows to be realized by means of the integrated five switches in the different modes BSE represents in greater detail.

It can be seen from the figures that the switchovers can each be carried out with five logic switches SW 1 to SW 5 in each bus coupler. These can be controlled by corresponding signals from the connected computer channels RK 7 or RK 2 via the computer interfaces RS. As already stated, two bus couplers each form a bus control unit BSE coupled via the connection interface VS. The logical switches are arranged so that both interconnections between the bus interfaces BS and BS 'and connections to the computer interface RS and the connection interface VS can be established. The bus interface BS can be connected via the switch SW 7 in switch position A, an EXOR gate 1 , the switch ter SW 2 in switch position A, an OR gate 2 and the switch SW 3 in switch position A with the bus interface BS '. A reception line RD is connected between switch SW 2 and EXOR gate 7 and leads via an OR gate 3 to the computer interface RS. The OR gate 3 is otherwise connected to the switch SW 5 in switch position B, which receives signals from the connection point VS via line VD 1 and in switch position A connects this line VD 1 to the EXOR gate 1 . From the computer interface RS, a transmission line TD leads to switch SW 4 , which in switch position A connects to OR gate 2 and in switch position B to another OR gate 4 , which can also be acted upon by switch SW 3 in switch position B and via Line VD 2 connects to the connection interface VS.

Fig. 11 shows a bus coupler of a bus control unit of a substation computer in the "NORMAL / RECEIVE" mode. The data flow runs there - e.g. B. coming from BUS1 - via the bus interface BS, the switch SW 7 / A, the switch SW 2 / A and the switch SW 3 / A to the further bus interface BS 'and from there back to BUS1. The assigned computer channel RK 1 or RK 2 is connected via computer interface RS and receive line RD between the first switch SW 1 and the second switch SW 2 . The paths via the other switches SW 4 / A and SW 5 / A are without current (no data flow).

(Note: The letters behind the switches show the respective switch location.)

For BUS 2 with reverse data flow, another similar bus coupler module - functionally swiveled by 180 ° - must be provided. Both bus couplers are to be coupled via the VS connection interface.

Fig. 12 shows the same bus coupler of a substation switched into the "NORMAL / SENDEN" operating mode. There is no data flow (coming from BUS 1 ) via the bus interface BS. SW 7 / A switch, SW 2 / A switch, and the path via the fifth SW 5 / A switch is de-energized (no data flow). In contrast, via the computer interface RS, the transmission line TD and the switches SW 4 / A and SW 3 / A, a connection to the relevant ring bus (here, for example, BUS 7 ) is made via the further bus interface BS '. Here too, two bus couplers set in this way are necessary for a complete bus control unit.

FIGS. 13 and 14 show the corresponding data flow in the bus couplers of the master computer LR on the status "NORMAL OPERATION / RECEIVING" or "POWER NORMALBE / SEND". The data flow in FIG. 13 runs for "RECEIVE" from the bus interface BS via switch SW 7 / A, gate 1 and gate 3 , line RD to the computer interface RS and in FIG. 14 for "SEND" from the computer interface RS via transmission line TD , SW 4 / A switch, OR gate 2 and SW 3 / A switch to the bus interface BS '(cf. also Fig. 1). In both cases, the switch SW 2 is in position B, ie open, in order to prevent endless circulations by interrupting the data flow.

Fig. 15 shows the bus coupler of a bus control unit of a substation computer in the "TEST / RECEIVE" mode. Here, the data flow from the ring bus via the bus interface BS, the switch SW 1 / A, the switch SW 2 / A and switch SW 3 / A to the further bus interface BS ', with the assigned computer channel via computer interface RS and receive line RD between the switch SW 7 and the switch SW 2 is connected and the paths via the other switches SW 4 / B and SW 5 / A are de-energized (no data flow).

For the "TEST / SEND" operating mode, reference is made to FIG. 16 for the previously described bus coupler of a substation. There is no data flow via the bus interface BS, the switch SW 1 / A, SW 2 / A, SW 3 / A to the further bus interface BS 'and the receive line RD and the path via the switch SW 5 / A is de-energized (no data flow ). In contrast, a connection to the other ring bus is made via the computer interface RS, the transmission line TD, the switch SW 4 / B, the connection interface VS and the respective other bus coupler of the same bus control unit BSE.

The other FIGS. 17 to 20 go into more detail on the "RESERVE" operating mode. There are different circuits for the bus coupler in the substations, depending on whether the respective bus coupler is at the beginning or end of a loop. Is the data flow z. B. coming from BUS 1 via bus coupler BUKO 1 and BUKO 2 to BUS 2 , there is a "loop 1/2" with loop start in BUKO 1 and loop end in BUKO 2 .

Fig. 17 shows that in the operating mode "RESERVE / RECEIVE" for bus couplers of a substation at the start of the loop the data flow via the bus interface BS and the switch SW 1 / A and then on the one hand via the receive line RD and the computer interface RS to the assigned computer channel and on the other hand via the switch SW 2 / A and switch SW 3 / B leads to the Ver connection point VS, the paths via the switches SW 4 / A and SW 5 / B being de-energized (no data flow).

In contrast, in the operating mode "RESERVE / RECEIVE" ( Fig. 18) for bus couplers of a substation at the end of the loop, the data flow from the connection point VS and switch SW 5 / A on the one hand via receive line RD and computer interface RS to computer channel RK 1 and on the other hand via switches SW 2 / A and switch SW 3 / A to the further bus interface BS ', the paths via switch SW 1 / B and switch SW 4 / A being without current (no flow). The circuits for the operating modes "RESERVE / SEND" at the start and end of the loop are also different.

In the operating mode "RESERVE / SEND" ( Fig. 19) for bus couplers of a sub station at the beginning of the loop, the data flow leads from a computer channel via computer interface RS, transmission line TD, switch SW 4 / A, switch SW 3 / B to the connection interface VS, whereby the paths via switches SW 1 / A, SW 2 / A and SW 5 / B are without current (no data flow).

Fig. 20 shows the operating mode "RESERVE / SEND" for bus couplers of a substation at the end of the loop. The data flow from a computer channel via computer interface RS, transmission line TD, switch SW 4 / A, switch SW 3 / A and the further bus interface BS 'to the bus interface BS' is performed. The paths are via the switches SW 1 / B, SW 2 / A and. SW 5 / A de-energized (no data flow).

During standby operation of FIG. 7 with active computer channel RK 1 corresponds to the switch position in the bus coupler BUKO 1 of the host computer LR for loading triebsart "RECEIVE" within the control station to that of FIG. 13 and "SEND" to that of FIG. 14. The bus coupler BUKO 2 is switched through in accordance with FIG. 11. In reserve operation with active computer channel RK 2 according to FIG. 9, the conditions are reversed. Bus coupler BUKO 1 is switched through in accordance with FIG. 11 and the switch positions for “RECEIVE” and “SEND” apply to the bus coupler BUKO 2 in accordance with FIGS . 13 and 14.

Claims (14)

1. Arrangement for the secure transmission of serial data in terms of signal technology between preferably two-channel, safe computers with a double ring bus system,

• - in which, during normal operation, the two ring buses of the double ring bus system flow through redundant parallel in the opposite sense, unidirectionally, and each computer with one channel with one ring bus and the other channel with the other ring bus via active bus couplers (BUKO) is connected in pairs, decoupled via an internal interface (VS), to computer-related bus control units (BSE),
• - In the event of a detected incident by switching the double ring bus system to test mode with cross-connections between the ring buses, a fault location and then another switch to reserve mode is provided, in which adjacent sections with separation of the faulty section continuously into one Simple ring structure can be transferred without redundancy,
• - That a two-channel master computer (LR) is provided, which communicates with two-channel substation computers (UR), manages the bus access rights and switches to test mode in the event of data flow disruptions in the ring buses during normal operation, in which the substation computers switch from the master computer to the assigned bus control units (BSE) for fault location localization and that further switching to the single ring structure then takes place via these bus control units (BSE),

characterized,

• that each of the two bus couplers (BUKO 1 , BUKO 2 ) of a bus control unit (BSE) associated with a computer (substation computer UR or master computer LR) is permanently assigned to one of the two ring buses (BUS 1 or BUS 2 ) and can be controlled by the associated computer channel, where each have a computer interface (RS) for the connection to the associated computer channel (RK 1 or RK 2 ) and bus interfaces (BS or BS ') for the incoming or outgoing connection of one of the two ring buses (BUS 1 or BUS 2 ) see easily are
• - And that the switching of the bus control units (BSE) in the different operating modes by 5 logical switches (SW 1 to SW 5 ) in each bus coupler, the switch by appropriate signals of the associated computer channel (RK 1 or RK 2 ) the respective computer interface (RS) can be controlled, whereby the malfunctions of the operating mode "NORMAL OPERATION" - with direct data passage in the bus control unit (BSE) in duplex mode - a switch to a two-step test mode with alternating computer channel participation for fault location and then to one in two alternating phases running reserve mode in simplex mode, in which loops are formed from one to the other bus coupler or ring bus.

2. Arrangement according to claim 1, characterized in that in the operating mode "NORMALBETRIEB / RECEIVE" in the bus couplers of the bus control units of the substation computers, the data flow via the bus interface (BS), the 1st switch (SW 1 / A), 2nd switch ( SW 2 / A) and the 3rd switch (SW 3 / A) to the other bus interface (BS ') is switched through, with the assigned computer channel (RK 1 or RK 2 ) via computer interface (RS) and receiving line (RD) between the 1st switch (SW 1 ) and 2nd switch (SW 2 ) are connected and the paths via the other 4th and 5th switches (SW 4 / A, SW 5 / A) are de-energized (data flow-free) ( Fig. 11 ). 3. Arrangement according to claim 1, characterized in that in the operating mode "NORMALBETRIEB / SENDEN" in the bus couplers of the bus control units of the substation computers no data flow via the bus interface (BS), the 1st and 2nd switches (SW 1 / A, SW 2 / A) and the path via the 5th switch (SW 5 / A) is de-energized (free of data flow), that against the computer interface (RS), the transmission line (TD), the 4th switch (SW 4 / A) and 3. Switch (SW 3 / A) a connection to the relevant ring bus via the other bus interface (BS ') he follows ( Fig. 12). 4. Arrangement according to claim 1, characterized in that in the operating mode "TESTBETRIEB / RECEIVE" in the bus couplers of the bus control units of the substation computers, the data flow from the ring bus via the bus interface (BS), the 1st switch (SW 1 / A), the 2nd Switch (SW 2 / A) and 3rd switch (SW 3 / A) runs to the further bus interface (BS ′), with the assigned computer channel via computer interface (RS) and receive line (RD) between the 1st switch (SW 1 ) and 2nd switch (SW 2 ) is connected and the paths via the other 4th and 5th switches (SW 4 / B and SW 5 / A) are de-energized (data flow-free) ( Fig. 15). 5. Arrangement according to claim 1, characterized in that in the operating mode "TESTBETRIEB / SENDEN" in the bus couplers of the bus control units of the substation computers no data flow via the bus interface (BS), the 1st, 2nd and 3rd switches (SW 1 / A , SW 2 / A, SW 3 / A) to the further bus interface (BS ') and to the receive line (RD), the path via the 5th switch (SW 5 / A) is de-energized (data free of flow), but via the Computer interface (RS), the transmission line (TD), the 4th switch (SW 4 / B), the connection interface (VS) and the other bus coupler of the bus control unit is connected to the other ring bus ( Fig. 16). 6. Arrangement according to claim 1, characterized in that in the operating mode "RESERVE OPERATION / RECEIVE" for bus couplers of a substation at the start of the loop, the data flow via the bus interface (BS), the 1st switch (SW 1 / A) and then on the one hand via the Receive line (RD) and the computer interface (RS) to the assigned computer channel and on the other hand via the 2nd switch (SW 2 / A) and 3rd switch (SW 3 / B) leads to the connection interface (VS), the paths via the 4th and 5th switches (SW 4 / A and SW 5 / B) are de-energized (data free of flow) ( Fig. 17). 7. Arrangement according to claim 1, characterized in that in the operating mode "RESERVE OPERATION / RECEIVE" for bus couplers of a substation at the end of the loop the data flow from the connection interface (VS) and the 5th switch (SW 5 / A) on the one hand via the receiving line (RD) and computer interface (RS) to the assigned computer channel and on the other hand via the 2nd switch (SW 2 / A), 3rd switch (SW 3 / A) to the further bus interface (BS '), the paths via the 1st switch (SW 1 / B) and 4th switch (SW 4 / A) are de-energized (free of data flow) ( Fig. 18). 8. Arrangement according to claim 1, characterized in that in the operating mode "RESERVE OPERATION / SEND" for bus couplers of a substation at the start of the loop, the data flow from the assigned computer channel via the computer interface (RS), the transmission line (TD), the 4th switch (SW 4 / A), the 3rd switch (SW 3 / B) leads to the connection interface (VS), whereby the paths via the 1st, 2nd and 5th switch (SW 1 / A, SW 2 / A and SW 5 / B) are de-energized (data flow free) ( Fig. 19). 9. Arrangement according to claim 1, characterized in that in the operating mode "RESERVE OPERATION / SEND" for bus couplers of a substation at the end of the loop, the data flow from the assigned computer channel via the computer interface (RS), the transmission line (TD), the 4th switch (SW 4 / A) and the 3rd switch (SW 3 / A) to the further bus interface (BS ′) is led, the paths via the 1st, 2nd and 5th switch (SW 1 / B, SW 2 / A and SW 5 / A) are de-energized (data flow free) ( Fig. 20). 10. A method for operating the arrangement according to claims 1, 4, 5, characterized in that for test operation, the bus control units (BSE) are switched over to who, in a first step using only one computer channel (for example RK 1 ) via which the master computer (LR) on the transmitter side to the first bus (e.g. BUS 1 ) and on the receiver side to the second bus (e.g. BUS 2 ) and the substation computer conversely on the receiver side to the first bus (BUS 1 ) and connected on the transmitter side to the second bus (BUS 2 ) so that all sub-stations belonging to this computer channel (USt) are called by the host computer via the first bus (BUS 1 ) by means of this one channel (RK 1 ) and only the intact substations can reply via the second bus (BUS 2 ) using the same computer channel (RK 1 ), that only the other computer channel (e.g. RK 2 ) is used in a second step, the host computer (LR) sending to the second bus (e.g. B. BUS 2 ) and on the receiver side to the first bus (z. B. BUS 1 ) closed and the substations vice versa on the receiver side to the second bus (BUS 2 ) and on the transmitter side to the first bus (BUS 1 ), that then all sub-stations belonging to this computer channel (USt) are called up by the host computer (LR) via the second bus (BUS 2 ) using this other computer channel (RK 2 ) and only the intact sub-stations (USt) via the first bus (BUS 1 ) using the can respond to the same computer channel (RK 2 ) and that the fault location (X) is determined from the send responses of the intact substations (USt) in the master computer (LR) ( FIGS. 3, 5). 11. A method for operating the arrangement according to claims 1, 6, 7, 8, 9, characterized in that the bus control units (BSE) are switched for reserve operation, only one computer channel in each case having the control function in the master computer and via only one bus is sent and received and through cross-connections in the bus control units (BS) adjacent to the fault location (BSE) of the substations, the data traffic is passed from one ring bus to the other and a loop is formed via the master computer (LR), via which one Simplex communication between the currently active control station of the host computer (LR) and the intact substations (VAT) takes place ( Fig. 7, 9). 12. A method for operating the arrangement according to claims 1, 6, 7, 8, 9, characterized in that in the first phase of the reserve operation, the first computer channel (z. B. RK 1 ) of the master computer (LR) takes over the control function and the other second computer channel (for example RK 2 ) is switched off, only the bus couplers (for example BUS 1 ) assigned to the first bus (for example BUKO 1 ) being sent and received while those for the second bus (e.g. BUS 2 ) assigned bus coupler (BUKO 2 ) are switched to pass through, so that the data traffic is only processed between all interfaces to the first computer channel (RK 1 ) and then the bus control unit (BSE) of the master computer (LR) is switched to the second phase of the reserve operation ( Fig. 7). 13. A method for operating the arrangement according to claims 1, 6, 7, 8, 9, characterized in that in the second phase of the reserve operation, the second computer channel (RK 2 ) of the master computer (LR) takes over the leading function and the first computer channel ( RK 1 is turned off), only via the associated second bus bus coupler (BUKO is transmitted and received 2), currency rend the the first bus (bUS 1) associated with the bus coupler (BUKO are switched to passage 1) that the traffic only between all interfaces to the second computer channel (RK 2 ) are processed and then the bus control unit (BSE) of the master computer (LR) is switched back to the first phase of the reserve operation, etc. ( FIG. 9).