Siemens Aktiengesellschaft

Hans Thinschmidt

Anton Sauer

Franz Fahrenschon

Alfred Meier

Rudolf Mittelmann

Eduard Scheiterer

Franz Kurfess

Horst Jager

Frank Schmidtke

An expansion network for increasing the number of subscriber terminations at a passive optical bus system comprising optical mixers is disclosed. The mixers are arranged in groups and the optical transmitters individually provided per subscriber are connected to the light receivers likewise individually provided per subscriber, being connected thereto in the manner of a mesh network via respectively only one of the mixers so that the attenuation of only one mixer is inserted into the optical path.

Expansion network for increasing the number of subscriber terminations

For the purpose of expanding the connection capacities of optical mixers in order to form a large network, series connections of such optical mixers are provided. In such networks, such series connections are formed of optical mixers which produce signal transmission paths which are identical to one another. No different signal transmission paths are present in the network overall.

Network comprising a multitude of optical signal transmission lines

A method is disclosed for automatic level matching in a local network, particularly for a multicomputer arrangement, comprising an optical bus system, for the purpose of collision recognition. Given a required level matching, the process is executed such that a fundamental phase is provided in which level matching devices respectively individually assigned to the computers are synchronized with one another. A first matching phase is provided in which all level matching devices simultaneously execute a process for setting a reference voltage to the lowest received level, whereby the sum of all attenuation components of the signal path at the receiving side of the appertaining computer is taken into consideration. A second matching phase is provided in which all level matching devices successively execute a process for setting the transmission level of their own transmitter such that the emitted light power at its own receiver leads to the receiving power registered as lowest, whereby the sum of all attenuation components of the signal path at the transmitting side of the appertaining computer is taken into consideration.

Method for automatic level matching in a local network, in particular a

Given a bus system comprising an optical waveguide, an electro-optical transmitter, and an opto-electrical receiver, the transmitter is constructed such that the light power coupled into the light waveguide and dependent on the information signal to be transmitted is variable in digital steps. The receiver is comprised of DC-coupled amplifiers without gain control. It contains a preliminary stage for generating a useful signal from the light signal, and has a first comparator stage for generating the information signal from the useful signal. The receiver also includes a second comparator stage to which a reference voltage variable in digital stages is supplied and which samples the level of the useful signal emitted by the preliminary stage. The second comparator stage emits a collision signal when the useful signal moves the reference voltage upwardly and thus indicates that at least two transmitters are coupling light into the optical waveguide. The structure of the transmitter and of the receiver enables a DC transmission circuit having the special advantages of the optical waveguide. By means of the adjustment of the transmitters and of the receivers, moreover it can be achieved that the simultaneous access of a plurality of transmitters to the optical waveguide can be determined from the height of the level of the useful signal emitted by the preliminary stage.

Bus system with optical waveguides having collision detection

An optical passive bus control system includes an access coordinator and control unit which is connected to the passive network in the same manner as other connected devices of the network. The access coordinator control means is located spatially close to the optical mixer, over connecting light wave guides which are as short as possible. The access coordinator and control unit contains a collision recognition device for recognizing an access collision, and includes means for implementing an asynchronous access operating mode in response to a collision recognition. A switch means is provided for emitting a signal to the bus, signifying a change to a synchronous operating mode in which no access collisions can occur.

Optical passive bus control system

A test facility is disclosed for error diagnosis in multicomputer systems, particularly in multi-microcomputer systems in which signal voltages on the system bus in the error diagnosis are made perceptible as optical signals by display devices directly controlled by the signal voltages. A decoupling device is provided for connecting an evaluation/control logic to the system bus and an address/data information display device, an access signal display device, a bus control signal display device and an interrupt signal display device are provided. At least one comparator module is provided whose first group of signal inputs receives a binary information corresponding to a selection address, adjustable by means of a selection switch, and whose second group of signal inputs receive information concerning the address line of the system bus. The comparator module, given equality of the binary information corresponding to the selection address and an occurring address information, emits an output signal to provide an access signal simultaneously occurring on an access signal bus line which is switched on for the test facility by way of at least one logic element. The address data information display device is released by an access signal switched on in such a manner and the access signal display device and the interrupt signal display device contain display elements of a first group for rendering perceptible the momentary states of all access signal bus lines and of all interrupt signal lines, and respectively contain a second group of display means for rendering perceptible the access signal and/or interrupt signal which was respectively most recently active.

Test facility for error diagnosis in multi-computer systems,

For extension of data traffic within a telephone exchange system to separate data exchange systems, special connecting sets, which are provided for data traffic within the telephone system, are fixedly connected via special facilities with subscriber exchange lines of the separate data exchange system. The special facility thereby takes over the function of the conversion from line and data signals from one system into the other and vice versa. For securing of telephone subscriber selection criteria in the case of arriving traffic from the data exchange system, arriving connection requests are only acknowledged if the selection digits which are necessary for the build-up of the telephone connection which conducts them further have arrived in the special facility. Besides this, the telephone ring signal for the desired telephone station is suppressed. The exemplary disclosre is particularly suited for the coupling of a telephone system with a separate telegraphy exchange system, whereby the selection possibilities of both systems can be used for telegraphy traffic.

Circuit arrangement for telephone exchange systems, especially

Apparatus is described for telecommunication facilities having transmission paths capable of accommodating different types of message switching, e.g., voice communications and data communications. A changeover device in the subscriber stations in the system switches between the two modes of communication by means of a mode selector switch for causing manual or automatic switching between the two forms of communication. After switching through a call carried by a given connector set, a signal is automatically sent from the connector set to the called subscriber station. This signal causes an automatic changeover from the form of message communication being used to a second form, e.g., from voice to data. Upon completion of the changeover in the called subscriber station, acknowledgement of this fact is made by sending a back signal from the called station. Responsive to this acknowledgement, a signal is likewise sent to the calling subscriber station. This signal automatically effects a changeover in the calling station to the desired mode of message transmission, and this changeover is likewise acknowledged by a back signal. The changeover is reported to both subscriber stations participating in a call as an inquiry for acceptance of the desired message switching.

Growing community of inventors

Germering, Germany

Hans Thinschmidt