DE2200773A1 - Interference-resistant communication system - Google Patents

Description

Communication system insensitive to interference

The invention relates to a communication system in which
a signal receiver is designed to receive a continuously repeated digital signal telegram, and to
Only actuate output devices if consecutive telegrams received are identical. To this
Possible errors in the transmission of the telegrams cannot operate the output devices if they are not repeated identically in successive telegrams.

The term "telegram" is to be understood below as a digi tal pulse train that contains a message in
coded form.

The invention is particularly - but not exclusively - applicable to communication systems between tracks and
Trains, in which information is transmitted from the tracks to the train and / or from the train to the tracks.

In train-to-train communication systems, information is transmitted in the form of digital telegrams, for example
from a transmitter on the side of the train to the eleventh ZUgj to monitor the movement of the train by transmitting control signals to the train driver or by automatically activating the train control unit. The information can be sent by * deffi

-S-

209833 / 100Θ

are transmitted via lines laid along the tracks, which are inductively coupled with antennas on the train, the antennas in turn feeding a receiving device on the train. The gloist telegram can e.g. contain information which is processed by a device on the train, uffles a visible signal to the train driver give.

The invention is based on the object in communication systems of the type described above, the susceptibility to interference against any errors that may occur to decrease.

According to the invention, this object is achieved in a communication system of the type described in which information is stored in Digital code is transmitted in the form of a repeatedly sent digital telegram, released by a receiver, which has a first register for receiving a series of coded digital input signal telegrams. This Register has one or more outputs, each of which is connected to an input of a bistable circuit is, and these outputs are energized according to the informa tion content of said telegram, and a second register, which receives the first telegram from the first register via a delay circuit, when the first register receives a second telegram of this series, whereby the corresponding outputs of the second Register with the corresponding second inputs of the bistable devices and the outputs of the bista bilen Facilities with the input of an output transformer are connected.

A preferred starting example of the invention is explained in more detail below with reference to the drawing, which shows a Shows a block diagram of a signal receiver circuit according to the invention.

A sequence of digital impulses that form part of the gram Form designated signal is fed to an input 10 of a register A! where the impulses are initially dtltfch

2Ö9Ö33 / 1ÖÖ8

a synchronization and parity checking device checked which can be constructed in various ways using known logic circuits. the Pulses are then fed to a shift register which, in a known manner, is made up of a series of flip-flops or others bistable devices, each stage, i.e. each flip-flop having a corresponding output, which is each connected to an output line. Depending on the content of the telegram, certain output lines are created 11 excited.

Each of these lines 11 is connected to one of two inputs of a series of bistable devices F ₁ , P 2 ... F, the number "n" denoting the number of lines

11 is identical. The excitation of one of the respective Lei lines 11 causes one of the bistable devices F, to put yourself in state "l", which is the first of theirs bistable states. A subsequent series of digital pulses at input 10 causes the present Information from register A into a delay network T and possibly after a corresponding delay in a second register B is directed, where .sie is checked for correctness and decoded, and the corresponding Output lines 12 are energized. Each of these lines

12 from the second register B is connected to the second input of the bistable circuits F ,, Fp ο..F. The excitation of the associated lines 12 causes the trains belonging bistable circuits F-, F ₂ ... F to put themselves in the state "2", which is the second of their two bistable states. This has the effect that the previously set bistable circuit F changes to state "2" -

The delay network T can be of any known type, but one which is preferably used in practice is available from a shift register with a number of flip-flops connected in series, but without parallel outputs. The size of the delay depends on the number of

209833/1008

Flip-flops in the register as the pulses from a flip-flop be forwarded to the next with each switching pulse. The larger the number of flip-flops, the larger is the number of switching pulses that occur when a single pulse passes through the delay network appear.

If the device is set up in such a way that a continuous sequence of these telegrams occurs, then this has the effect in the associated bistable circuits F ,, Fp ... F the reception of set and reset pulses, which are separated by the delay circuit T. The bistable The device works as a 1: 2 divider and the resulting alternating output is via a transformer Ij3 used to operate a lamp, relay, or any other output device required. If one or both of the registers A or B should fail, the bistable circuits receive F., Fp ... F only from one of these registers pulses and consequently the output of the bistable circuit is not in the form of a Be AC voltage and is therefore blocked by the transformer IJ. The outputs are similar of the bistable devices should not be an alternating voltage, which in turn means that they are blocked by the transformer IJ if an error occurs during the transmission of the telegrams, so that successive telegrams are not identical.

A further improvement in safety can be achieved by designing the transformer IJ as a step transformer so that the devices operated by it have a much higher working voltage than the digital-logic circuit. Any error of the transformer IJ, such as a short circuit between the primary and secondary ^{coil, etc.,} therefore, results in no undesired actuation of the output devices.

Further optimization of the system can be obtained

209833/1006

if desired, that the output of each of said bistable circuits len P, by a configuration of the delay circuit T - ^ p * "" n ^ ^e ^ ^ne square-wave voltage with a duty ratio of 1:. 1.

The "telegram" information of the facility described above can either be through a conductor cable or through Punk are transmitted.

The invention is not limited to the illustrated and described exemplary embodiment. It also includes everyone professional modifications as well as all partial and sub-combinations the features and measures described and / or shown.

- Expectations -

209833/1006

Claims (4)

Expectations Ι ») Communication system in which information is transmitted in digital code in the form of repeatedly transmitted digital telegrams, characterized by a receiver with a first register which is designed to receive a series of encoded digital input signal parts and this register contains one or more Has outputs, each of which is connected to an input of a bistable "circuit, these outputs being excited depending on the information content of the telegrams, with a second register for receiving the first telegram from the first register through a delay circuit when receiving a second telegram Row through the first register, the corresponding outputs of the second register each being connected to the corresponding zv / siten input of a bistable circuit, the output of which is connected to the input of an output transformer. 2.) Communication system according to claim I ₃ characterized in that each of the registers contains a test unit and a shift register with one or more outputs. J.) KoKimunikationssyster; '! according to claim 1, characterized labeled in zei Chne t that -each of · bistable circuits than 1 ^ flip-flop --Teil 'he formed is fc. 4.) KoujAUs.xUT'.t-xonzsys'oetA according to one of the preceding claims, characterized in that r; e ^ enn "oiMi net that the transformer as A ¹ Ii ¹ V" -. i "a-dpanniuv ^ tiaru; .'or ^ at ^ r is trained. 209833/1006