DK141229B - CONNECTING AC POWER TRANSMISSION AND DATA TRANSFER WITH FREQUENCY CONVERSATION - Google Patents

Description

(11) PUBLICATION WRITING 1 ^ -1229 \ £ H / DENMARK (51) int.ci.3 h oa l 27/10 • (21) Application No. 4735/71 (22) Filed on 29th ββρ. 1971 (23) Race stage 29 · eep. 1971 (44) The application presented and a

forwarded reading the quoted offer on the ^ ^βυ. 1 yoU

DIRECTORATE OF

PATENT AND TRADE MARKET <30) Priority requested from it

50 Sep I97O, 2048118, BE

(71) SIEMENS SHARE COMPANY, Berlin v. Muenchen, 8 Muenchen 2, Wittels-TJacherplatz 2, BE.

(72) Inventor: Hans-Heinrich Voss, 8 Muenchen 21, Landsherger Stresse 353, BE.

(74) Plenipotentiary in the proceedings:

International Patent Office.

(54) Coupling for AC telegraphy and / or data transmission with fre = frequency switching.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a switch for AC telegraphy and / or data transmission with frequency switching, in particular for the tone frequency range, in which the two states of the binary signal intended for transmission are transmitted by one of two frequencies in a transmission channel in a multichannel system and there is a frequency stable oscillator connected to a frequency divider to which is connected a switching means, which is followed by a further coupling which produces the frequency level required for the wiring output to the transmission channel, the frequency divider having a number of outputs corresponding to the desired frequency level When selected, uniformly designed channel transmitters can be connected and, where appropriate, also channel receivers.

Such couplings are e.g. known from German publication specification No. 1 762 603 and requires a frequency adjustment or replacement of the filters upon frequency change.

2 141229

Telegraph and data transmission facilities within the tone frequency range have long been known and have been continuously improved. In known systems, the transmission portion of each transmission channel contains a tone frequency generator which, corresponding to the supplied DC telegraph signals, produces one of two frequencies having a particular frequency distance, the so-called frequency swing, from the center frequency of the transmission channel concerned. Furthermore, the transmitting portion contains special filters, which are closely adapted to the transmission channel, which are designed as band filters and suppress cross talk to or from other channels as a result of the harmonics produced.

Similar filters such as a discriminator is present in the receiving portion of that channel, so that the coupling range, especially with regard to self-inductions, is considerable due to the high demands on the filters. In addition to systems with frequency switching or frequency modulation, amplitude modulated systems are also known, whose significance has, however, declined in relation to systems of the former type. From the German publication specification No. 1,762,603 there is known a frequency switching telegraph system, in which a frequency-stable oscillator delivers a single frequency to a sub-switch which feeds a switching means which causes an additional frequency divider to transmit one of two frequencies on the line. .

Modern AC telephony systems with frequency modulation also allow data transmission, with the possibility of transmission speeds exceeding 50 Baud. Such a plant is known under the designation WT 1000 and is described in Siemens-Zeitschrift No. 44, 1970, Booklet 4, pages 178-180. In the present invention, it is intended to reduce the switching supply of the transmitting and receiving couplings belonging to the individual transmission channels and to provide the possibility of simply switching the transmitting and receiving couplings for operation in connection with transmission channels for other frequency levels, without, not during fabrication, time-consuming countervailing work is required. Further advantages of the invention will become more apparent from the following.

According to the invention, the task according to the invention is solved by the selection means for the channel transmitters and receivers being performed without coils and, if they require control frequencies, also connected to said frequency divider, and that at least in one channel receiver there is a discriminator coupling, which at one an input limiting receiving pulse is applied to an input and at a second input a comparative pulse sequence is compared which is compared with the receiving pulses in such a way that the output of the discriminator coupling is applied only to a signal when there is a frequency difference between the receiving pulses and the comparison pulse.

In such a coupling design, the self-inducing self-inducements in the channel transmitters and receivers, which are known in the prior art, are eliminated for which exact equalization is required. Conveniently, the transmit and receive filters can be designed without coils in the form of n-way filters composed of low pass filters, so that by changing the connections of the channel transmitting and receiving units to the frequency parts coupled to the oscillator, a switch to another transmitter is made possible. - and receiving channel, so that if possible 1 channel channel transmitters and receivers are designed as a unit *

The frequency divider connected to the oscillator can advantageously be configured as a binary frequency divider, at whose outputs different pulse sequences of different frequency can be supplied via gate couplings which can be supplied to the individual channel transmitters and receivers by selection.

According to a further development of the invention, it is ensured that the frequencies taken from the frequency parts following the oscillator are so high above the rated frequency of the channel in question that phase deviations are reduced by means of a fixed frequency divider which is essentially the same for each channel.

An embodiment of the invention is characterized in that, at a higher frequency level operating at a higher frequency level, a frequency converter is coupled to a frequency converter which translates the frequency frequency coming from the line to a higher frequency level and is fed from the frequency divider with an auxiliary frequency.

The invention will now be explained in more detail with reference to the drawing, in which 1 is a block diagram of one embodiment of the coupling according to the invention; FIG. 2, in tabular form, shows the binary representation of the rated frequencies of a 24 channel FM 120 system in the voice band with a frequency swing H of 30 Hz. 3 at a, b, c and d show a pulse diagram; 4 shows a possible embodiment of a transmission filter SF and receiving filter EF in FIG. 1, a three-way filter used; FIG. 5 shows a possible discriminator coupling; and FIG. 6 is a further embodiment of channel transmitter and channel receiver.

In connection with the embodiment of FIG. 1 must first describe the principle of frequency generation. In an FM 120 system, in which in the voice band for transmitting binary signals, e.g. For telegraph signals, at a rate of 50 Baud, there are 24 channels with a frequency fluctuation of H = 30 Hz and a channel width of 120 Hz, the center frequencies of the channels or the signal frequencies of the signals and the intersection frequencies between neighboring channels can be stated as multiples of the frequency fluctuation H 30 Hz. Since the available frequency band, the voice band, only extends within 7 to 3.4 kHz, there are less than 2 = 128 frequencies F. These frequencies 4 141229 can therefore be represented as multiples of 30 Hz by a seven digit binary speak up.

6 (1) F = 30 · Τ ~ 2 £ „* 2 J where £„ = 0 or 1 n = o

In the described embodiment, the required frequencies are first generated 3 in one by a factor z, e.g. 10, a higher frequency level to reduce any distortion, which will be discussed in more detail below. Thus, in the elevated frequency level, the frequencies can be written as follows:. 6 (2) z · F = 30 · z ·> I £ n * 2, where £ n = 0 or 1 n = o For details, refer to the one in FIG. 2 shows the channel number and associated rated frequencies as multiples of H = 30 Hz in the decadic and binary number system.

In the embodiment shown in FIG. 1, there is provided for generating said frequencies a principal oscillator 0 which produces a frequency F0, e.g. may have the value 30 · z · H Hz. This frequency may e.g. amount to 4 MHz. The main oscillator 0, e.g. may be designed as a quartz stabilized oscillator and for which, in the event of a disturbance, a corresponding, switchable spare oscillator may be provided, is connected on the output side to a frequency divider TI, e.g. may consist of a seven stage binary frequency divider of known embodiment. By means of a gate coupling GF known per se and not shown in detail, the frequency divider TI * s seven outputs are in a known manner decoupled from each other and led to seven output terminals AO ... A6, which can be coated by selection, as well as to an output terminal. A (2).

As will be apparent from the following, the connection of terminals A0..A6 to the gate coupling GF may be introduced in accordance with the numerical value of the binary expressed multiple.

Of the output voltages from the frequency divider T1 shown in line 1-8 in FIG. 3a-d, are formed by the gate coupling GF of FIG. 1 shows seven pulse sequences shown in lines 9-15 in FIG. 3a-d. Furthermore, at the output AS a further offset pulse sequence (2), which is shown in line 16 in FIG. 3a-d and used in the particular discriminator used in the embodiment of FIG. 1.

The lines 9-15 of FIG. 3, at the outputs of the gate coupling GF are arbitrarily additively miscible. In this way, any pulse frequency z · F can be generated in accordance with Equation (2). Hereby the impulse sequences, where the same coefficients have the value one, are produced by connections and transitions (x) of the order n between the gate circuit GF and further subsequent gate circuits.

In this way, all frequencies for the WT channels in the FM 120 system and similarly for other systems with a larger channel width can now be generated in the frequency frequency increased by the factor a · By adding the binary summed components of pulse sequences in accordance with Equation (2) can initially only derive the desired pulse frequencies, ie. the desired number of pulses per second. However, these impulses are not equidistant, but are subject to phase deviations. However, in the described embodiment, these phase deviations can be reduced by a subsequent frequency division with the divisor z to such a value that they can be ignored if z is chosen sufficiently large.

Another possibility for frequency generation is to use two frequency dividers, the first of which has a fixed sharing ratio and the second can be controllably changed as a frequency changes. Furthermore, it is possible to consider the period of the oscillator frequency as a time element and, by means of a counter, reach the half-period of a desired frequency by counting.

In the embodiment shown in FIG. 1, a transmitter input terminal SE is supplied with a DC transmitted binary input signal. A subsequent low pass filter TPI serves in the usual way for interference impulse suppression. If decoupling of the coupling is required from the input line, a low-pass filter is connected to a converter 0E1, which may be designed as a magnetic or optoelectro-coupling means. At the second input of an AND circuit G1, the pulse frequency z * 2H is applied, which can be decoupled from the output coupling GF's output A1. Thus, in the one characteristic state of the applied binary signal, the frequency z · 2H is at the output of the gate circuit G1 and thus at the input of a gate circuit G3, and at the occurrence of the second characteristic state, the gate circuit G1 is blocked. Depending on whether the modulated gate circuit G1 is open or locked, the pulse frequencies z (FM + H) at the output of gate circuit G3 occur. After sharing with the divisor z in the subsequent frequency divider T2, the line over the transmit filter SF and the low-pass filter TP2, which serve for oscillation suppression, are fed a signal nt the frequencies F + + H.

In FIG. 2, all frequencies for the signal states of the FM 120 system are shown, which frequencies are expressed as multiples of the frequency swing H * 30 Hz. From the expressions in binary digits which immediately give the coefficients in Equations (1) and (2), the following will appear: Since all multiples are odd, the last column will always contain the number "1". As a result, in FIG. In the gate coupling GF's output AO is permanently connected to the OR circuit G3.

In the penultimate column of the binary numbers of FIG. 2 represents for each channel the number 0 for the lowest and the number 1 for the highest rated frequency, therefore the output A1 of the gate coupling GF in fig. 1 is connected to the gate circuit G3 over the modulated gate circuit G1. The gate circuit GI is blocked or open depending on the state of the input signal.

---- 6 · All other binary digits 1 fig. 2, i.e. kMÉ ^ MHMkåMSlnmediated and determines the connections to be drawn between partlillHB [| BBBBw> 'oak 62. For channel # 20, e.g. outputs A3, A4 and A6 fa ^^^^ J ^^ HHplMvdaen 62. The output of the circuit 62 is also connected to i1iWF'klf0> ea 63. It can be seen from this that by a simple connection of certain inputs # eg exits between the gate connections 62 and 6F for the individual channels, transmit and receive couplings which are coupling identical if equipped with coil-free filters, e.g. gyrator or n-way filters.

In the embodiment shown in FIG. 1, the transmission filter Si * and «the take-off filter EF are made as three-way filters. Such filters are the embodiment of the embodiment, these filters may consist of three uniform laVjna ^^ 2a ^ fg ^ & j £ cense frequencies equal to half the bandwidth of the Η5πΗρη «ί * i to be generated. The input and output of the filter are connected in cyclic ndÉI ^ Elge to each of the three low-pass filters, which is shown in the drawing switching switches SIm1 ^ Oyyt of switches SI and S2, which change with frequency 3 FM and controlled (f on distributor D. The switches can be realized by using transistors, such as the JMMMMMfl · pulse sequences appropriate frequency and phase location.

In another possible embodiment shown in filter input terminals EF and output terminals AF, between the coefficients, an amplifier V with a feedback circuit RK is located in front of the input current MHjPVrmftlet one of three capacitors C1, C2 and C3 in connection with aadgHinJljJ R2 consisting of low pass coupling. A switch SU switches on the switchwidth% JjwgÉjn ^ octors C1, C2 and C3 and may conveniently be realized by # PBJBB | BBBIsfcores supplied to control pulse sequences in such a way that these impulses sequentially connect capacitors C1, C2 and C3 to land. Similar to the one shown in FIG.

1, the switch SU must thus be switched at frequency 3 F ^ so that the capacitors C1, C2 and C3 with the same frequency MMtfMtfHfttfNBp, ... are grounded one after the other. For this purpose, a ford <tiS ^ ||| J || JP8E ^ produces iHpuls sequences which are offset relative to each other. These add-on filters as the receive filters in the respective channel transmitter and tutt * 2 »odCager respectively, and for the frequency generation, serve jointly for the transmitter and transmitter channel in the frequency divider T3 together with the oscillator 0, the frequency divider and the gate couplers. .

The signal obtained from a wiring network L and transmitted to the receiver input terminal EE is separated into the receiving filter EF from the other channels and fed to the low-pass filter TP3, which serves for suppression suppression. Following the low-pass filter TF3, a constraint BV follows, in which the signal amplifies # And / Jadaøeff at the same amplitude.

A discriminator DS consists of a frequency divider T ^, working with the divisor Z and over an AND circuit G ^, the pulse frequency Z (FM + 2 H) is assigned to the pulse frequency Z (FM + 2H) 7 141229 from an OR circuit In connection with a tipping stage K1, this coupling acts in the same way as a monostable tipping coupling and allows a comparison of the received pulses with a locally generated pulse sequence. In the event of a polarity shift in the receiving signal at the output of the limiter BV, the tipping stage K1 is switched on. so that the gate circuit is opened and the pulse frequency Z (FM + 2H) is applied to the frequency divider T ^. After a period corresponding to the duration of a half period for the frequency + 2H, at the output of the frequency divider T ^, a voltage change follows, which in turn controls the kip stage K ^ and, where appropriate, the divider to the rest position. Since the half-period of the frequency + 2H is shorter than any time section between two consecutive polarity shifts in the receive signal, that of the toggle switch K ^, the gate circuit G ^ and the the clutch consisting constantly ready for activation when the next polarity shift in the receive signal occurs. The comparator stage V, which is applied to the working voltage from the tipping stage K1 and the signal voltage, only gives a voltage of the same polarity to the low-pass filter TP4, as long as the half-period of the receiving signal lasting between two polarity shifts lasts longer than the fixed half-period produced by the tipping stage K1. After carrier filtration, ie. The low pass filter TP ^ produces a voltage at its output which has the same polarity, but different size, for the two rated frequencies of the channel.

Another discriminator coupling is shown in FIG. 5s Instead of the one in the embodiment of FIG. 1 pulse frequency Z (F 1 + 2 H) is used pulse frequency Z. F ^ which is applied to two uniform controllable frequency dividers and T ^ f over the associated control gate circuits and G ^ ', the control over associated tilting couplings K ^ and K ^' being effected in the same manner as described above for the one shown in FIG. 1 discriminator coupling. Unlike this, the coupling units K

However, Gg, and K ^, Gg, T₂, alternate for successive half periods of the receiving signal, using two complementary outputs from a flip switch KQ switched by the receiving signal. Instead of a comparison step V as in FIG. 1, two diaphragm formers and D 1, such as e.g. emits positive pulses when the half-life of the receive signal is longer than the fixed half-term of the frequency FM, and otherwise produces negative pulses. The outputs of the differential couplings and D 1 are jointly connected to the low-pass filter TP 2, at whose output a positive voltage occurs when the rated frequency contained in the receive signal is less than the center frequency of the channel FM, and otherwise a negative voltage. Such a discriminator, which at the threshold threshold F5 between the highest and lowest signal frequency of the signal gives the voltage value 0, is transfer technically favorable, since the difference threshold is also maintained at different magnitudes of the voltage at the signal frequencies.

If the transmitter S and receiver E are to be summarized as a pair, but work at different frequency levels, the following components of the transmitter S and receiver E must be constructed separately: The gate circuits and G ^, the frequency divider and the distributor coupling D to produce the two band filters SF and EC necessary coupling impulse is.

Mechanical filters can also be used for the band filters in transmitter S and receiver E.

In this case, it is particularly advantageous if all channel transmitters KS1 and channel receivers KE1 in a system as shown in the embodiment of FIG. 6 is operated at the same frequency level. Hereby, the transmitter KS1 and the receiver KE1 may be constructed in the manner described above, e.g. as shown in FIG. 1. The transmission to the desired frequency level for the transmission line and the reverse side on the receiving side is carried out by means of frequency converters FU1 and FU2 which contain the coupling necessary for this purpose. The auxiliary frequencies needed for the conversion are also derived from the frequency of the common oscillator 0 over the frequency divider T and the gate coupling GF. Also in this embodiment, the advantage exists that the channel transmitters KS1 and the channel receivers KE1 can be designed uniformly for all channels in a system and that the frequency location can be set by a correspondingly selected connection with the frequency divider switch. As the transmit and receive filters SF1 and EF1 are the same for all channels, they can be manufactured at a low cost for fabrication in large numbers. Suitably, ceramic filters or coilless filters are used which, as mentioned, require an auxiliary frequency. This can be removed from the main oscillator over the frequency divider couplings.

Also in the embodiment of FIG. 6, the advantage is that the distortions are small, since the scanning takes place at an increased frequency level. Due to the use of digital signals, the supply of building components is low and the reaction to the sinusoidal signal at the transmitter output is carried out in a manner known per se by means of a low pass filter TP.

Claims (6)

141229 9 1. Switching to AC telegraphy and / or data transmission with frequency switching, in particular for the tone frequency range, in which the two states of the intended binary signal are transmitted by one of two frequencies in a transmission channel in a multi-channel system, and wherein there is a frequency stable oscillator (0) connected to a frequency divider (T ^) to which is connected a switching means (G3) followed by a further coupling (T2) which produces it for the line output (L) of the transmission channel required frequency level (FM), wherein the frequency divider (T ^) has a number of outputs to which, corresponding to the desired frequency level by selection, uniformly designed channel transmitters (KS) and, if appropriate, also channel receivers (KE), characterized by the selection means for the channel transmitters and receivers are designed without coils and, if they require control frequencies, are also connected to said frequency divider and that at least i n channel receiver (KE) is provided with a discriminator coupling (DS) which at one input is supplied with amplitude limiting receive pulses and at another input is supplied with a comparison pulse sequence which is compared over kip steps (K ^, K ^ ') in such a way as to receive pulses. the output of the discriminator switch is only applied to a signal when there is a frequency difference between the receiving pulses and the comparison pulse sequence. Coupling according to claim 1, characterized in that low pass filters (SF) are provided as a selection means at least in the transmitter. Coupling according to claim 1 or 2, characterized in that a transmitting filter (SF1) located at the switching means (KS1) is operable at an elevated frequency level and is followed by a frequency converter (FU1) which causes the reduction to the frequency level required for the line transmission and is fed. from the frequency divider (T) with an auxiliary frequency. (Fig. 6). Coupling according to claim 1 or 2, characterized in that a receiver filter (EF1) operating at an elevated frequency level operating at an elevated frequency level is coupled to a frequency converter (FU2) which converts the frequency level coming from a line (L) to a higher frequency level and is fed from the frequency divider (T) with an auxiliary frequency. (Fig. 6). 5. Coupling According to one or more of the preceding claims, characterized in that the channel filters at least in the transmitter are made of low pass filter-three built-in n-way filters (SF). Coupling according to one or more of the preceding claims, characterized in that for generating control pulses for the channel filters (SF, EF), the associated transmitters (KS) and receivers (KE) are connected to a fixed frequency divider (T ^), which over gate couplings (GF) are connected to the outlets of the frequency divider (T ^) coupled to the oscillator (0).