JPS643096B2 - - Google Patents

Description

[Detailed description of the invention] Technical field of invention The present invention relates to a method for monitoring multiplexing/demultiplexing equipment.

Background of the Technology In order to use transmission paths efficiently, low-order group signals are multiplexed into high-order group signals, and conversely, high-order group signals are separated into lower-order group signals.
Multiplexing and demultiplexing equipment is used for this purpose, but
Normally, in order to improve reliability, a spare multiplexing/demultiplexing unit is added to the group of multiplexing/demultiplexing units for each line, and if one of the multiplexing/demultiplexing units corresponding to the active line has a failure, Instant backup multiplex
Maintain switched lines in separate units. However,
If even this backup multiplexing/demultiplexing unit fails, it will no longer be possible to switch over to the active backup. The present invention primarily refers to a method for monitoring whether this spare multiplexing/demultiplexing unit maintains normal operation.

Prior Art and Problems Conventionally, a spare multiplexing/demultiplexing unit in a multiplexing/demultiplexing apparatus has been monitored by supplying it with a test signal from a test signal generator (described in detail later). However, the spare multiplexing/separating unit is connected to the current multiplexing/separating unit group by fixed wiring so that it can be switched at any time. For this reason, the test signal will circulate to other lines via the fixed wiring. Therefore,
By providing switches at required locations on this fixed wiring and opening and closing them as appropriate, collision between the test signal and the original transmission signal on the line is avoided.
Therefore, there are disadvantages in terms of hardware, such as the presence of the switch being essential and the need for a separate test signal generator. This is the problem.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to propose a method for monitoring a multiplexing/demultiplexing device that can reduce the number of switches as much as possible and eliminate the need for the test signal generator.

Structure of the Invention In order to achieve the above object, the present invention is characterized in that an operation test of the spare multiplexing/demultiplexing unit is performed using the transmission signal itself on the line.

Embodiments of the Invention First, a conventional multiplexing/demultiplexing device (hereinafter sometimes simply referred to as a device) will be described.

FIG. 1 is a circuit diagram showing a conventional multiplexing/demultiplexing device. In the figure, 11-1 is a current multiplexing/demultiplexing unit, and there are n similar units. In the figure, the n-th active multiplexing/demultiplexing unit 11-n
are shown (hereinafter these may be abbreviated as current units). Each active unit is provided corresponding to each line, and includes a multiplexing section that multiplexes the first signal _S1 of the low-order group into the second signal _S2 of the high-order group. Specifically, the first signal S ₁ (actually there is a group of S ₁ of multiple channels, for example, S ₁ of 4 channels, but only the signal of the first channel is shown) is sent to the low-order group switch 12-11 ( Current unit 11-1 1st
The signal passes through the amplifier 13 and switch 14 in the 12-11 (in the sense of equivalent to a channel), and reaches the bipolar/unipolar converter (B/U) 15 , where it becomes a unipolar signal _S1 and is sent to the multiplexer (MUX) mentioned above.
16, and the second signal S ₂
becomes. Note that a converter (B/U) 15 compatible with the fourth channel is also illustrated. On the other hand, the third signal _S3 of the high-order group enters the separation section (DMUX) 19 in the active unit 11-1, where it is separated into, for example, four channels of low-order group signals.For example, the first channel signal is sent to the switch 12. -11 and becomes the fourth signal _S4 .

A spare multiplexing/demultiplexing unit 21 (hereinafter sometimes simply referred to as a spare unit) is commonly connected to the plurality of active units 11-1 to 11-n. This is to immediately replace the function of any of the active units 11-1 to 11-n when it fails and maintain the line. If the current unit 11-1 fails, the switch 14 is turned off, the switch 23 is turned on (these on/off operations are performed by a central processing unit (not shown)), and the first signal _S1 is sent through the amplifier 22. The signal is applied to the multiplex section 25 in the standby unit 21. Bipolar in the front stage/
A unipolar converter (B/U) 24 is placed. The signal multiplexed by the multiplexer 25 is sent to the selector 18-1.
becomes the desired second signal _S2 . On the other hand, the third signal S ₃ is guided by the selector 26 to the separating section 27 in the standby unit 21 and becomes the fourth signal S ₄ via the selector 20. Here is the current unit 1
Switching to the spare unit 21 of 1-1 is performed.
The wiring of the selectors 18-1, 20, and 26 is switched from the input/output side of the active unit 11-1 to the input/output side of the standby unit 21 by a central processing unit (not shown).

By the way, the spare unit 21 is normally idle. That is, in the event that the current unit fails, it will only operate until it is repaired. Therefore, this idle spare unit is used for testing the currently used units. Inspection unit 31 cooperates with standby unit 21 for this inspection. This test is performed as follows. For example, if the multiplexing section 16 of the current unit 11-1 is to be inspected, the first signal _S1 is used as the first comparison input, the switch 23 is turned on,
The signal is applied to a comparator (COMP) 34 through a bipolar/unipolar converter (B/U) 32 and a selector 33 of the inspection unit 31. On the other hand, the output of the multiplexer 16 is branched via the selector 26,
Separation section 27 and selector 28 in spare unit 21
The signal obtained through the test unit 31 is led to a comparator 34 in the inspection unit 31 as a second comparison input. If these comparison results do not match, an alarm ALM is sent to notify of an abnormality. Similarly, the third signal _S3 is sent to the selector 26, the separation unit 27 in the spare unit 21,
the first comparison input via the selector 28;
The third signal is passed through the separation unit 19 in the active unit 11-1, the selector 29, and the selector 33 in the inspection unit 31 as the second comparison input, and if these comparison results do not match, an alarm ALM is sent out to indicate an abnormality. Let me know.

If the spare unit 21 is to have an inspection capability as described above, the quality of the unit itself becomes an issue. In other words, the spare unit 21 must always operate normally. For this purpose, the inspection unit 31 is used again and the test signal generator 41 is introduced to inspect this spare unit 21.
Moreover, this generator 41 is used for the current units 11-1 to 11-1.
- It can also be used to test n. However, the main purpose of the generator 41 is to inspect the spare unit 31, and the generator 41 is mainly used for inspecting the active units 11-1 to 11-n.
The test for is "subordinate". Switches 42-1 to 42-n are provided for this "sub" test. On the other hand, a switch 42 is provided for the "main" test, and the test signal passing through this is applied directly to the test unit 31 as a first comparison input, and on the other hand, the test signal passing through the switch 42 is applied to the spare unit 21. The signal passes through the multiplexer 25, the switch 43 (which is turned on for this test and is normally off), and the separator 27, and is selected by the selector 28 and then applied to the test unit 31 as a second comparison input. If the comparison results do not match, spare unit 2
1 error, an alarm ALM is sent. Note that the other switches 43-1 to 43-n can be used for turn-back tests and the like for each current unit.

In the system shown in Figure 1, switch 42-1
.about.42-n, 42 are essential for preventing signals from passing around to other lines, and the test signal generator 41 is also necessary. Also, switches 42-1 to 42-n,
In addition to 42, a switch 14 for each line is also essential. This is because if any of the switches 42-1 to 42-n is turned on and a test signal is flowing, the first signal _S1 on the line must not be mixed therein. The present invention provides these switches 4
2-1 to 42-n, 42, switch 1 for each line
Even if 4 and the test signal generator 41 are eliminated,
This allows equipment to be monitored. This will be explained below.

FIG. 2 is a circuit diagram showing the multiplexing/demultiplexing device of the present invention. In this figure, the same components as in FIG. 1 are designated with the same reference numbers or symbols. First, it should be noted that the test signal generator 41 of FIG. 1 has been removed from the circuit configuration of this figure. It should also be noted that by removing the generator 41, the switches 42-1 to 42-n and 42 in FIG. 1 and the switch 14 corresponding to each line were also eliminated. Even if the switch and generator 41 are eliminated in this way, the original monitoring of the device can be maintained. This allows the present invention to transform the conventional test signal into a raw first
This is because the signal was replaced with the signal _S1 . Since the raw signal is directly used as the test signal, the switches 42-1 to 42-n and the switch 14 for each line are not needed to avoid collision between the raw signal and the test signal, as in the conventional system. Further, the switch 42 is also unnecessary.

In FIG. 2, when inspecting the spare unit 21, for example, the first signal _S1 of the working unit 11-1 is extracted. That is, switch 23 is turned on. This is then given to the inspection unit 31 as a first comparison input. On the other hand, the extracted signal S ₁
is multiplexed by the multiplexing section 25 of the spare unit 21, turned back by the switch 43, and separated by the separating section 27 to generate a signal that should be the same as the original signal _S1 , and then sent to the inspection unit 31 via the selector 28. Second
Give as comparison input. If the comparison results of the first and second comparison inputs do not match here, an alarm will be generated.
Sends ALM and learns of the abnormality in the spare unit 21.
Such inspection of the spare unit 21 can also be applied to each working unit, if necessary. For example, on the one hand, the signal S ₁ is sent to the inspection unit 31 by turning on the switch 23, which is used as the first comparison input, and on the other hand, the signal S ₁ is sent to the inspection unit 31 with the switch 23 turned on.
1, is turned back by switch 43-1, is sent to inspection unit 31 through selector 29, and is used as a second comparison input to compare the two.

Effects of the Invention As explained above, according to the present invention, even if the hardware of a conventional multiplexing/demultiplexing device is simplified, the device can still be monitored in the same way as the conventional multiplexing/demultiplexing device. It is advantageous for reducing costs.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing a conventional multiplexing/demultiplexing device.
FIG. 2 is a circuit diagram showing the multiplexing/demultiplexing device of the present invention. 11-1 to 11-n...Currently used multiplexing/demultiplexing equipment,
16, 25... Multiplexing section, 19, 27... Separating section, 21
...Spare multiplexing/demultiplexing device, 31...Inspection unit,
34...Comparator, 43...Switch, _S1 ...First signal, _S2 ...Second signal, _S3 ...Third signal, _S4 ...Fourth signal
signal.

Claims (1)

[Claims] 1. A current system for multiplexing a first group of signals of a lower order group into a second group of signals of a higher order group and separating a third signal of a higher order group into a fourth group of signals of a lower order group. It has a plurality of multiplexing/demultiplexing units corresponding to each line, a spare multiplexing/demultiplexing unit that is commonly connected to the plurality of active multiplexing/demultiplexing units, and a standby multiplexing/demultiplexing unit that cooperates with the said spare multiplexing/demultiplexing units. a testing unit for testing said active multiplexing and demultiplexing unit; One of the signals is used as a first comparison input, and a signal corresponding to the one signal that has passed through the spare multiplexing/demultiplexing unit is used as a second comparison input, which is selected according to the results of these comparisons. In the multiplexing/demultiplexing device for determining the quality of one of the currently used multiplexing/demultiplexing units, the testing unit uses the first signal taken in from the selected one of the lines as a first comparison input, and The signal is inputted to the multiplexing section in the spare multiplexing/demultiplexing unit, and then the output is folded back and inputted to the separating section, and the obtained signal is used as a second comparison input to perform the multiplexing/demultiplexing of the preliminary multiplexing/demultiplexing unit according to the results of these comparisons. A method for monitoring multiplexing/separating equipment to determine the quality of the separating unit.