SU1142897A1 - Device for measuring slippage quantity - Google Patents

Abstract

MEASURING AMOUNT OF QUANTITY OF CROSSING, containing input decoder, generator, serially connected counter and indicator, characterized in that, in order to improve measurement accuracy, two elements are introduced into it, a prohibition element, two triggers, a differentiating circuit and two delay elements, In this case, the output of the decoder is connected to the inputs of both delay elements and to the first inputs of the first element I and the prohibition element, the second inputs of which are combined and connected to the output of the generator, and the outputs are connected to connecting the inputs of the first trigger, whose output and output of the first delay element are connected to the corresponding inputs of the second element, whose output and output of the second delay element are connected to the corresponding inputs of the second trigger, whose output through the differentiating circuit is connected to the generator control input and to the counter input . u 00 co

Description

The invention relates to communication technology and can be used in the measurement technique of digital communication systems. A device is known - a console for testing linear paths containing a master oscillator, the output of which is connected to a pulse distributor (RI), to the first input of the counter, to the input of a pseudo-random sequence generator (GPS), the first output of which is connected to the first input of the first through the error input unit the code converter, the output of which is the output of the measuring device, and the device input is connected to the second counter input through the serially connected second code converter and the error detection unit, m vhodpervo second code converter depending on the position of the switch may be connected to the second output unit CST or yield RI SP unit. A disadvantage of the known devices is the low measurement accuracy associated with the same type of fixing by the counter of an error packet and slippage in the digital channel. The closest to the proposed rto technical essence and the achieved result is a device for measuring the amount of slip containing a decoder, a generator, a meter connected in series and an indicator C23 at the input. However, this device is characterized by insufficient accuracy in the fixation of slippage associated with two phenomena. Firstly, if an error packet occurs in the digital channel or interrupt, this device records the slippage of which is not. Secondly, the slippage arising during the search for cyclic synchronism, for quite a long time, cannot be fixed, since this state does not correspond to the operating state of the device. The purpose of the invention is to improve the measurement accuracy. The goal is achieved by the fact that two elements AND, a prohibition element, two triggers, a differentiating circuit and two delay elements are inserted into the slip measurement device, containing a series-connected counter and an indicator, while the output of the decoder is connected the inputs of both delay elements, to the first inputs of the first element I and the prohibition element, the second inputs of which are combined and connected to the output of the generator, and the outputs are connected to the corresponding inputs of the first trigger Whose output and the output of the first delay element connected to the corresponding inputs of the second AND gate, whose second and Exit delay element output connected to respective inputs of the second flip-flop, whose output is connected through a differentiating circuit to the control input of the generator and to the input of the counter. Figure 1 shows the structural electrical circuit of the device for measuring the amount of slippage in figure 2 - the time diagram of the device operation in the presence of slippage; TSS. The device for measuring the amount of slippage contains a decoder 1, a counter 2, a generator 3, an indicator 4, the first element AND 5, the second element AND 6, the prohibition element 7, the first trigger 8, the second trigger 9, the first delay element 10, the second delay element 11 differentiating circuit 12. When a pseudo-random sequence (psi) is fed to the digital channel input, the device is connected to the channel output. The operation of the device is based on the fact that, in the absence of slippage, the cyclic clock signal (DSS) is received at the same points in time as the signal from the generator. The occurrence of slippage leads to a shift in time of the position of the CSL, to the fixation of slippage and the restructuring of the device to a new position of the CSL, i.e. to prepare for fixing a new slippage. Consider using the timing diagrams presented in Figures 2 and 3, the operation modes of the blocks included in this device. The device works as follows.

. In the absence of cyclic sync signal (DSS), i.e. during cyclic synchronism, the output of the decoder 1 is fixed to a periodic mode of units, corresponding to the appearance on its output of the DSS. The distance between units corresponds to the duration T of the first memory cycle.

. Since there is cyclic synchronism, the sequence of units at the output of generator 3 corresponds exactly to the sequence of units at the output of decoder 1. It has the same sequence of units. the place at the output of the first element AND 5a all units From the output of the decoder 1 are prohibited by the prohibition element 7. Hence, at the output of this element, the units are missing and the first trigger 8 is in a low-voltage state. Therefore, there are no units at the output of the second element I 6, and the second trigger 9, under the influence of units passing from the output of the decoder 1 through the second delay element 11, is in a low-voltage state. The absence of changes in the state of the second trigger 9 and, therefore, the absence of pulses at the output of the differentiating circuit 12 means the absence of changes in the operation of the device, which corresponds to the absence of slippage.

When projectile DSS (Fig.2A) fixed by the decoder after a certain duration relative to the previous TsSS (Fig.2B). As can be seen from the diagram, the instants of occurrence of units at the output of generator 3, starting from the second unit, do not coincide with the instants of occurrence of units at the output of decoder 1. As a result, at those times when the units at output of decoder 1 and generator 3 do not coincide , there are no units at the output of the first element And 5, but then there are units at the output of the element of prohibition 7 (Figure 2b). These units transfer the first trigger 8 to the high-voltage state (Fig. 2d) and open one input of the second element 6, thereby preparing it for operation. Units also from the output of the decoder 1 through the first delay element 10 arrive at the other input of the second element And 6 (Fig.2E). The delay time is chosen equal to the SRP cycle, i.e. equal T. When the units from the output of the first trigger 8 and the first delay element 10 coincide in time, the units at the output of the second element 6 appear (Fig. 2e), which leads to the transfer of the second trigger 9 to the high-voltage state (Fig. 2g). ). The leading edges of the pulses, the passage through the differentiating circuit 12 (Fig. 2h), are counted in the counter 2, fixed by the indicator 4 and the generator 3 is set in such a state that the next unit at the output of the generator 3 appears at the time interval T after the unit is applied to generator 3 input. Due to this, the device enters the operation mode without slippage. The return of the second trigger 9 to the low-voltage state occurs from the units at the output of the decoder 1 through the second delay element 1 1.

There are two more modes in the digital channel that need to be considered: imitation of the CCS in an uncharacteristic position, i.e. the arrival of false CCS and the disappearance of one cycle of true CCS. Both of these phenomena are due to errors in the transmission of a digital signal through the channel and should not be recorded as slippage.

Fig. 3 shows the time diagram of the device operation when a false DSS appears, marked in Fig. In the index L. The appearance of an additional DSS leads to the appearance of an extra unit at the output of the decoder 1, as well as forming a unit at the output of the inhibit element 7 (Fig .1b) and the transition of the first trigger 8 to the high voltage state (Fig. 3b). However, the first trigger 8 again returns to the low-voltage state by the first element AND 5 until this moment when a unit (Fig. 3g) is output from the output of the first delay element 10 to the input of the second element AND 6. Therefore, the unit does not form the output of the second element And 6 and in connection with this, the second trigger 9 is all the time in the low-voltage state and no slip is detected. In case of violation of the cyclic sync signal (fig.Zd) or during a break in the digital sequence S114

No state of slipping occurs because trigger 8 continues to be in the low voltage state.

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Thus, the device has a higher measurement accuracy for slipping since it does not fix interruptions and cyclic sync signal damage (as well as caused by error packets in the digital signal) as slippage and does not respond to false cyclic sync signals after fixing the slippage in just 2 T restores its readiness to accept slippage.

The technical and economic efficiency of the device is associated with an increase in the accuracy of measurements. A device adopted as a prototype, along with slippage, can fix error packets as slippage, and also because of the long device restructuring time after fixing slippage it may not fix closely spaced slippings. This may lead to the fact that a usable digital channel will not be put into operation, and, conversely, a digital channel that is defective in slippage will be transferred to the consumer. Thus, the total economic effect is due to an increase in the efficiency of using digital channels on a communication network.

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Claims (1)

DEVICE FOR MEASURING THE NUMBER OF SLIPPINGS, containing an decoder, a generator, a counter and an indicator connected in series, characterized in that, in order to increase the measurement accuracy, two I elements, a prohibition element, two triggers, a differentiating circuit and two delay elements are introduced into it wherein the output of the decoder is connected to the inputs of both delay elements and to the first inputs of the first element And and the inhibit element, the second inputs of which are combined and connected to the output of the generator, and the outputs are connected to the corresponding to them the inputs of the first trigger, the output of which and the output of the first delay element ¹ are connected to the corresponding inputs of the second element And, the output of which and the output of the second delay element are connected to the corresponding inputs of the second trigger, the output of which is connected through a differentiating circuit to the control input of the generator and to the counter input . Figure 1