JPS6331979B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a multiplexing circuit that multiplexes n low-order group signals into a high-order group signal, and particularly relates to a multiplexing circuit that eliminates the influence of disturbance. It is related to.

(b) Prior Art and Problems An example of a conventional multiplexing circuit will be described with reference to the drawings. Incidentally, here, a case where PCM signals are multiplexed will be explained as an example. Figure 1 shows conventional PCM
1 shows a configuration diagram of an embodiment of an interface section of a transmission device.

In the figure, 1 to 5 are PCM24 communication path group (hereinafter referred to as PCM24CH), 6 is an interface section,
7 to 11 are high-order group conversion circuits, 12 is a clock pulse generator, 13' is an OR circuit, 13 is an interface circuit, 14 is a PCM120CH multiplex conversion device,
15 is an output terminal.

FIG. 2 is a diagram for explaining the operation of FIG. 1. 1 to 8 show signal waveforms at points 1 to 6 in FIG. 1, respectively.

In Figure 1, each of the 5 PCM24CHs 1 to 5, the low-order group PCM signal, is connected to the high-order group PCM120CH.
The signal is input to each of higher-order group conversion circuits (panel sheets) 7 to 11 of the interface section 6 of the multiplex conversion device 14. In addition, the clock pulse generator 12 of the high-order group conversion circuit outputs φ ₁ of different phases,
Clock pulses of φ ₂ , φ ₃ , φ ₄ , and φ ₅ (hereinafter referred to as clocks) are sent to the corresponding high-order group conversion circuits 7 to 7.
11, and the signal of PCM24 is shown in Fig. 2 1~
The signals #1 to #5 of the higher order group shown in FIG.
The converted signals of higher order groups #1 to #5 are outputted from the respective higher order group conversion circuits 7 to 11, and are processed by the OR circuit (hereinafter referred to as OR gate) 13' of the interface circuit 13 as shown in FIG. 2. The signals are synthesized and output from the output terminal 15.

However, the system shown in FIG. 1 has the following drawbacks. That is,
A power supply of 5 volts and a ground E are connected to each of the above-described high-order group conversion circuits 7 to 11. Here, the high-order group conversion circuit 7 will be explained as an example. Now, at point A shown in FIG.
When inserting it into the rack No. 4 (the same effect is obtained even when it is attached and detached),
Either the 5 volt power supply or the earth E will be connected first. In this case, one of them will be connected first, so that a disturbance 7-1 as shown in FIG. 2 will occur. This disturbance 7-1 is input to the OR gate 13'. Since other higher-order group signals #2 to #5 are input to the OR gate 13, this disturbance 7-1 causes other multiplexed signals (in this case #2, #3 , #4).

(c) Object of the Invention In order to solve the above-mentioned drawbacks, it is an object of the present invention to provide a multiplexing circuit that does not cause disturbance even when a high-order group conversion circuit panel sheet is attached or detached while the transmission device is in use.

(d) Structure of the Invention According to the present invention, the above-mentioned object is to provide a plurality of output means for outputting input parallel signals in a time-division manner only at allocated time intervals, respectively corresponding to the input signals, and to In a multiplexing circuit that combines outputs and outputs them as a multiplexed signal, each of the output means includes a selection means for time-divisionally passing through each of the output means outputs only in the same time interval assigned to each output means. This is achieved by a multiplexing circuit characterized in that a plurality of selection means are provided corresponding to the selection means, and the outputs of the respective selection means are combined.

(e) Embodiments of the invention The following description will be made based on the embodiments shown in FIGS. 3a and 3b and the time chart in FIG. 4.

In Figure 3, 1 to 5, 7 to 12, and 15 are the first
The same parts with the same functions as in the figure are shown.

As already explained in Figure 1, each PCM24CH
Each of the signals #1 to #5 is converted into the multiplexed signals #1 to #5 of FIG.
6 is input. The selection circuit 16 has a circuit configuration consisting of AND gates 16-1 to 16-5 as shown in FIG. 3b.

AND gates 16-1 to 16- of selection circuit 16
The clocks φ 1 to φ 5 output from the clock pulse generator 12 used in the high-order group conversion circuits 7 to 11 are inputted to each of the gates ₅ and ₅ , and the high-order group signals corresponding to these clocks are sent to the respective AND gates 16-1 to 16-1.
Select at 16-5.

Each transmission path a of the selected higher-order group signal,
Figure 4.
The signals are multiplexed into #1 to #5 as shown in FIG.

Now, when the panel sheet of the high-order group conversion circuit 7 is inserted into the PCM120 multiplex conversion device in the same manner as described above, a disturbance 7-1 shown at 7-1 in FIG. 7 occurs.
However, the multiplexed signal #1 is the AND of the selection circuit 16.
Since the gate 16-1 selects and outputs a clock having a phase of _φ1 , disturbances not synchronized with the clock of _φ1 are not outputted from the AND gate 16-1. Therefore, AND gates 16-1 to 16-
The high-order group signals #1 to #5 outputted from
3' is input. The superimposed signals #1 to #5 shown in FIG.
The same multiplexed data as in FIG. 6 is output from the output terminal 15.
It is output from

(f) Effects of the Invention According to the multiplexing of the present invention, the disturbance that occurs when attaching and detaching the PAL sheet of the high-order group conversion circuit of the interface section is blocked by the AND gate circuit corresponding to the panel sheet, so that multiple low The multiplexed signal converted from the next group to a higher order group has the advantage of being able to remove the influence of disturbance.

[Brief explanation of the drawing]

Figure 1 shows the interface section of a conventional PCM transmission device, Figure 2 shows the time chart of Figure 1, and Figure 3 shows the time chart of Figure 1.
Figures a and b show examples of the present invention, and Figure 4 shows a time chart of Figure 3. In the figure, 1 to 5 are PCM24CH, 6 is an interface section, 7 to 11 are high-order group conversion circuits (panel sheets), 12 is a clock pulse generator, 13 is an interface circuit, 13' is an OR circuit, and 16 is a selection circuit. , 14 is a PCM120CH multiplex converter, 1
5 is an output terminal, and 16-1 to 16-5 are AND gates.

Claims (1)

[Claims] 1. Multiplexing, in which a plurality of output means are provided, each corresponding to the input signal, to output parallel input signals in a time-division manner only at allocated time intervals, and the outputs from the output means are combined and output as a multiplexed signal. In the converting circuit, a plurality of selection means are provided corresponding to each of the output means for passing the output of the output means in a time division manner only at the same time interval as that assigned to each output means, and each of the selection means A multiplexing circuit characterized by combining outputs.