Circuit arrangement for telecommunications, in particular telephone switching systems with at least two computers for alternately controlling switching operations.

Description

Neither the switching requests nor the follow-up pulses are received there. This ensures that in such a case, all lines are still routed to the next available line. According to a further development of the invention, different transmission lines are used for the after-pulses when switching between computers. Switching devices are provided as for the switching requirement. Another embodiment of the invention provides that each connector contains a test device which checks before each switching operation whether This measure makes sense. For example, if only one computer is still working, there would be no point in trying to replace it with another computer. to switch, because then only very limited operation would be possible with a computer that was already identified as faulty, or it would be the The entire exchange was taken out of service. The invention is explained in more detail below with reference to an embodiment shown in the drawing. In this example, the switching system contains the two computers R1 and R2 and two connectors VI and V2. Each of the connectors VI and V2... is a \nzahi of peripheral devices pan-connected, which are only accessible via the responsible connector. However, if a larger number of peripheral devices are required than can be connected to the two connectors, another one will be needed. The number of connectors built into the switching system is [number missing]. The two computers, RX and R2, do allow for the control of a larger system. It is [missing information]. However, it is also possible to provide one or more additional computers as backups. How the individual peripheral devices P are to be connected to the computers R 1 or R 2 via the connectors Vl and V2 is not the subject of this document. the invention and therefore not described in detail. It is also not described how the veins a to h, and thus also al X and al2, are separated from the The monitoring devices of connectors V1 and V2, not shown here, continuously check in a known manner for the presence of a [missing information] in the The monitoring devices of computers R 1 and R 2 apply a resting potential that can only be transmitted via uninterrupted wires, is being checked. Each of the two connectors V1 and V2 is equipped with a switching device UX or U2, respectively. This switching device is shown in system mi; two A bistable multivibrator is used in computers to respond to a switching request, from one computer to another, and from the other computer to the other. is brought into a state. Such a switching request is sent to input al 1 in the computer R1 in a known manner, not described in detail here. Computer Rl is connected to input al2. These switching requests from computer R ! are given in the form of a pulse or continuous signal. The signals are routed via wires a and c to the right-hand inputs of the switching devices UX and U2. Corresponding switching requirements The signals from computer R2 are fed analogously to the left inputs of the two switching devices. With further connectors, their inputs also receive these signals. Switching devices transmit these impulses in the same way. In multiple computers, the bistable flip-flops UX and U2 are replaced by counting chains that have as many links as there are computers. and are switched on by the switching requests. The switching requests are triggered, for example, manually using buttons, by a monitoring device in case of a fault, or in certain time intervals (routine switching) are given. The switching devices LJI and LJ2 have the task of switching, according to the switching requirement, the following (not shown in detail here): between the computers via the connectors to the peripheral facilities P, lines running from the main computer to a backup computer to switch. The operating status of the respective computer is indicated during this process. Each switching device only switches the portion of the peripheral devices that is connected to the respective connector V1 or V2. which houses the switching unit UX or U2. This is done by generally blocking the line receivers, so that the lines running from the computers to the connectors are in the connectors and the lines running in the opposite direction be blocked in the computer. In the drawing, only the lines arriving from the computers are shown as representative of all operations. R21, R12 and R22 are shown, which terminate in the amplifiers for incoming traffic VV1, VV21, VV12 and VV22 respectively. The lines are shown in reverse. Directions 11, 21, 12 and 22 are connected to amplifiers VR11, VR2X, VR12 and VR22 respectively. A switching request from computer R 1 is transmitted via wires a and c in parallel to both switching devices U 1 and U2 in the Connectors V1 and V2 transmit the signal. This pulse causes amplifiers VV11, VV12, VR11, and VR21 to be disabled. Simultaneously, the Amplifiers VV21, VV22, VR 12 and VR 22 are open. Before this switchover, however, it is examined in a test facility (not shown here) whether a switchover is even useful. If the backup computer is also reported as defective or not connected, the switchover will not occur. If an error in the system led to the switchover... If the computer is switched over, an alarm will be triggered. If the switchover was performed by the computer as part of a test routine, the alarm will not be displayed. If, for example, a component fails or there is external interference, such as in the computer's monitoring system or along the route, Up to input al 1 or a / 2, only one of the switching devices UX or 112 has switched correctly. This is only a part of the peripheral devices. Pan connected the new computer. The devices belonging to the other connector P remain connected to the old, defective computer. To avoid this, the switching commands, which come to the open circuits R1 and R2 via at least one of the wires b or e or g, The signals are routed to gates G1 and G2. These signals, via outputs A1 and A2 respectively, cause the computer's operating status to be displayed. Simultaneously, in the computer R 1, which transitions from the operating state to the standby state, they trigger ^n time element ZX, which generates a follow-up pulse. for a predetermined period of time, the signal is again applied to the right-hand inputs of the switching devices UX and U2 via wires a and c. This The after-pulse is simultaneously received in the computers and connectors, in a manner not shown, as an acknowledgment pulse for e',ze. Completed shutdown. evaluated the operating computer. Were the two switching devices UX and (72) in connectors VI and V2 already switched? 5 6 This after-impulse remains ineffective, but also led to the safety of veins a, c, and h. a malfunction or component failure in one of the increases, it is also possible to only the switching operation- Kinrichtungen only for a partial switching of the inputs al I and :il2 via these wires The line system is routed to the replacement computer R2, so that the subsequent pulses from the timers Z1 are routed by this pulse, the switching also occurs in the second circuit and Z2, but separate wires lead to the inputs of the Connection carried out. Switching devices I) and i / 2 are to be provided. This includes 1 sheet of drawings.

Claims

Patent claims:

1. Circuit arrangement for telecommunications, in particular telephone switching systems, with at least two computers for alternating control of switching operations and with at least two connectors, each of which has a number of peripheral devices connected, wherein each The connector contains a switching device which, in the event of a fault or during routine switching operations, switches the peripheral devices connected to it to a switching request originating from one computer (operating computer) is disconnected from that computer and forwarded to the next computer (Reserve computer) connects and initiates a corresponding switching of the lines running between the computers and the connectors, characterized by the fact that each of the computers (R 1, R 2) contains a timer (Zi, Z2), that the timer (Z 1) of the respective computer (R 1) at Transition of this computer (R 1) from the operating state to the standby state for a predetermined period of time for the purpose of generating and transmitting a After-pulse to the switching devices (Ui, Ul) of all connectors CV1. V2) is switched on;rd, and that these switching devices (Ui, U2) a switchover between the computers (R 1, R 2) and the, which may not yet be fully completed by all connectors (Vi, V2). Catch up on the connecting lines (rii ...r22,v\' ... &ngr;22) (V1. V2).

2. Circuit arrangement according to claim 1, characterized in that different transmission lines (a, c) are provided for the follow-up pulses than for the switching requirements.

3. Circuit arrangement according to claim 1, characterized in that the switching devices (U 1, U 2) in the connectors (V 1, V2) are made of bistable tilting steps exist.

4. Circuit arrangement according to claim 1, characterized in that each connector (Vi, V2) contains a test device which is installed before each The switching process checks whether this measure is appropriate, and if the test result is negative, the switching process is omitted, and an alarm is activated if necessary. becomes. The invention relates to a circuit arrangement for telecommunications, in particular telephone switching systems, with at least two computers. for alternately controlling switching operations and with at least two connectors, each of which can be connected to a number of peripheral devices. is connected, with each connector containing a switching device which, in the event of a fault or during routine switching operations, switches the connection to it connected peripheral devices in response to a switching request issued by one computer (operating computer) from that computer disconnects and connects to the next computer (backup computer) and performs a corresponding switch between the computers and the caused by connecting cables. When transmitting the switching request, it can happen that it does not reach the switching device of one or more connectors. because the request impulse *u was short or too weak and therefore not all switching devices could be activated. Due to external influences However, an external potential can also activate one of the switching devices, so that in this way the switching devices of the system are in their The assumed switch position does not match. In such cases, some of the peripheral devices remain connected to the switched-off computer. while the peripheral devices that are connected to &ngr; in Those connected to other connectors will now be operated by the previous backup computer. In the book "International Conference on Communication", 1970, CaL No. 70 C CON, it is described on pages 11-30 and 11-31, v. This generates a secure switching pulse to switch from one control unit (computer) to the other. The two computers operate alternating in such a way that after each scan process, the system switches from one computer to the other so that the latter can perform the next scan. The scanning process is executed. At the end of a work period for the respective unit, an "end-of-scan" signal is sent to a monitoring device. Given, which performs a switch to the other unit. If this signal does not arrive within a time measured by a timer. If the scan duration exceeds the longest possible scan time, it will be considered an error. The scan will then be automatically switched to the other device. constantly switching and an alarm sounding. The invention does not deal with the generation of an "end-of-scan" pulse, nor with the Generating a substitute pulse if this pulse fails to occur, but requires that this switching request or a corresponding The replacement impulse properly initiated the switch from one computer to the next, and this switchover of the computers also has taken place. The object of the invention is to provide a circuit arrangement that enables the switching of all peripheral devices in systems of the input ensures that the aforementioned type of fault is transmitted to the respective operating computer in the event of one of the aforementioned faults. According to the invention, this is achieved by each computer containing a timer element, and by the timer element of the respective computer being activated during the Transition of this computer from operating state to standby state for a predetermined period of time for the purpose of generating and transmitting a After-pulse to the switching devices of all connectors is switched on, and that these switching devices may still have a to catch up on the switching of the lines running between the computers and the connectors that was not fully carried out by all connectors. By generating a follow-up pulse of a defined duration and sending it to the switching devices, the advantage arises that the switching request is repeated by a different device that operates almost completely independently of the first. A further advantage is that this follow-up pulse is only generated when the switching request reaches at least one of the connectors, this connector triggers a switching of the computers, and the operating computer has received and is currently executing the switching command. This follow-up pulse thus simultaneously acts as confirmation of the execution of the switching command. If one of the lines used to transmit switching requests from the computers to the switching devices is interrupted, problems arise.