Abstract: The invention relates to a circuit arrangement for connecting several trunk lines via PCM circuits to an exchange-internal switching network, for use in a switching-oriented system, preferably in an electronic data switching system, with at least two line and trunk groups, that form a redundancy pair and have at least one cross-connection, with each line and trunk group having at least one central controller, at least one interface to the exchange-internal switching network, a line circuit area for the PCM circuits and at least one transformer/framer for synchronization for each PCM circuit, with the switching arrangement being configured in such a way that a fault occurring in the circuit arrangement affects only a maximum of two PCM circuits. The invention is characterized in that switching elements, that directly and asynchronously select the PCM circuits individually and one of the two central controllers optionally, are positioned before the transformers/framers.

Abstract: Until now static switching signals have been used for triggering a switching device. This has the disadvantage that such static switching signals controlled by an exciter device can also occur in the event of a failure of the exciter device and then may effect faulty control of the switching device. In order to avoid this disadvantage, the switching signal is such that the signal state of the switching signal which is intended to effect the switching into the protection-switching state coincides with the signal state occurring upon failure of the exciter device.

Abstract: Method for alternate circuiting of a data stream. In the prior art, the switch status of a switchover means was controlled by what is referred to as an activation means. This has the disadvantage that a faulty control of the switchover means can occur given outage of the activation means. In order to avoid this, the switchover signal output from the activation means to the switchover means is provided such that the switchover means can automatically implement the alternate circuiting given outage of the activation means.

Abstract: In a method for monitoring existing telephone connections, particularly permanently switched telephone connections, the information that correspond to one another and come from the redundant switching network halves (SN0, SN1 ) are compared to one another. The information intended for forwarding to connected lines is branched in the interface (LTU) at the line side into a separate time channel (K0) and is transmitted back to the interface (LIU) at the switching network side and are compared thereat to said information. Information coming from the lines is branched into the separate time channel and is transmitted in parallel with the original information to the interface (LIU) at the switching network side. The branched information is compared to the original information in the interface (LIV) at the switching network side. The procedures ensue time-channel-by-time-channel.

Abstract: Interface module supports communication between processor systems. Communication between processor systems should chronologically burden the processor systems as little as possible. To this end, an interface module is utilized that supports the communication between two processor systems in the form of a process-parallel servicing of the two interfaces to the two processor systems.

Abstract: Line terminal groups are redundantly present for reliability reasons. The connecting through of the input lines to the switching matrix network can thereby proceed via different signal paths. In order to avoid disturbances during switch-over between signal paths, the appertaining interfaces are provided with compensation memories. The data contained in the compensation memories are written in or read out in a phase-synchronized and frame-synchronized manner with a uniform clock. The uniform clock is acquired from the electronic switching device base clock of the system. Due to transient time distortions and component tolerances, the base clock must be regenerated with the circuit arrangement of the invention before it is applied to the compensation memories.

Abstract: The interfaces between line terminator groups of a pair of redundant line terminator groups each comprise an interface circuit which makes it possible, by being equipped with a write-read memory, a switch-over device and a control device that controls these components, to test the interface parts belonging to an active line terminator group in a spot-check fashion during a time channel reserved for this purpose and to test the interface parts belonging to the passive line terminator group during all time channels on the basis of a respective check word mirroring.

Abstract: In a circuit configuration for clock-controlled time division multiplex telecommunications switching installations, including PCM telephone switching installations with central switching network and connected subswitching networks, line groups are connected to a central switching network via time division multiplex lines and have one subswitching network and one group control unit each are pairwise assigned to each other. Line units which are individually assigned to the one or the other of two line groups are, in normal operation, connected to the subswitching network of their own line group and can be changed over to the subswitching network of the particular other line group in standby operation. In the line units, equalizing memorys are provided in duplicate and, specifically, in each instance for the message stream to and from line group-common subswitching network, on the one hand, and for the message stream to and from the subswitching network of the particular partner line group.

Abstract: A receiving circuit for evaluating check words received after traversing a test loop for coincidence with the check word transmitted is utilized in time-division multiplex operation for the sequencing of test implemented in parallel and is reached via a multiplex line on which a defined time slot is allocated to each of the tests.

Abstract: A harmonic tone having an amplitude which is significantly lower than a fundamental audible tone is superimprosed on the audible tone to drown out quantization noises for audible tones transmitted in digital telecommunications exchange systems.

Abstract: For generating test words that are sent across a test loop and are monitored at the receiving side for coincidence and with the corresponding, transmitted test word, a memory is read in which such test words that preferably correspond to test words generated by a pseudo-random generator are stored. In the course of the monitoring, the memory is read again under the same address as in the transmission, but delayed by the running time of the test loop, in order to supply the test word that is to be compared to the received test word.

Abstract: Terminal groups are connected to a central switching matrix network via time-division multiplex lines and each comprises a switching matrix sub-network and a group controller which are assigned to one another in pairs. In addition to the connection equipment that are individually assigned to the one and to the other of the two terminal groups and that are respectively connected to the switching matrix sub-network of its own terminal group via internal lines during normal operation and that are switchable to the switching matrix sub-network of the respective other terminal group, the time-division multiplex lines individually extending from the central switching matrix network to each of the terminal groups are also switchable from their own terminal group to the respective partner terminal group.

Abstract: In a circuit arrangement for telecommunications exchanges, including PCM time division multiplex telephone exchanges with a central switching array and connected subordinate switching arrays, line terminal groups connected to a central switching network by way of link connections where each line terminal group has its own subordinate switching array and a group control unit are arranged in pairs. Within each line terminal group, there is terminal equipment for connection of outside lines on the one hand, and on the other hand link terminating circuits for the link connections to the central switching array can also be switched from the subordinate switching array of the respective line terminal group to that of the partner line terminal group. Terminal equipment and link terminating circuits as well a subordinate control units with subordinate switching arrays are equipped with three internal power supply systems and three internal clock pulse supply systems per line terminal group.

Abstract: Line groups with doubled central switching network and connected via correspondingly two time division multiplex lines and having inter alia one sub-switching network and one group control system each are assigned to each other in pairs. The connection devices, which are individually assigned to the one and the other of two line groups, and which are connected via internal lines in normal operation to the sub-switching network in each instance of their own line group, can be changed over to the sub-switching network of the particular other line group.

Abstract: A telecommunication exchange system has a plurality of switch facilities over which signals are emitted on an average only during a part of their respective occupation. A signal current source for emission of the signals is provided having a call-handling capability limited by signal current load. A signalling system is provided for serving a distribution of the load and provides pulse sequences having respectively identical pulse spacings. Pulses of different pulse sequences simultaneously transmitted over different switch facilities have chronologically different phase relations and a chronological offset from switch facility to switch facility. The offset is such that the pulses of the different pulse sequences connect chronologically to one another with respect to pulse termination and pulse beginning. The switch facilities are allocated for receiving the pulse sequences from the signalling system to a respective one of the pulse sequences of a specific phase relation.

Abstract: A subscriber connection circuit comprises heat resistors which can be bridged in a low-ohmic manner and an indication circuit which effects different indication functions. Four different operating states are possible, characterized by the nature of the feed, the switching threshold for the indication circuit, and the actuation of a filter element for the indication circuit, two of which operating modes represent the ringing phase and the ringing interval. During the ringing interval, the nature of the feed and the threshold voltage are identical to those in the conversation operating state, but in contrast thereto the filter element is actuated.