JP3076103B2 - Loopback control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loopback control system in which identical devices having a loopback function are connected in a plurality of stages.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional loopback control system.
Reference numerals 1-2, 51-3, and 51-4 denote multiplexers (MUX) each having a function of multiplexing data. Reference numeral 22 denotes a test device which transmits a test pattern to each of the multiplexers 51-i (i = 1 to 4).

FIG. 6 is a block diagram showing a main part of a conventional loop-back control system. In FIG. 6, reference numeral 60 denotes a loop-back control unit.
0 is provided in each multiplexing device 51-1 and includes a demultiplexing unit 1, a loopback code identification unit 2, a multiplexing unit 4, a folding unit 5, interfaces 31, 33, and a control unit 32.

Here, the separating section 1 separates input data into a main signal and a data link signal, the loopback code identifying section 2 identifies a loopback code, and the multiplexing section 4 includes The main signal and the data link signal are multiplexed.

[0005] The return means 5 sends the input data to the device back to the upstream device. Interface 3
Reference numeral 1 denotes an interface for transmitting input data to the demultiplexing unit 1, and interface 33 is an interface for transmitting output data from the multiplexing unit 4. Control unit 3
Reference numeral 2 designates whether or not loopback control is to be performed on the loopback means 5 based on the identification result of the loopback code identification unit 2.

With such a configuration, in a data transmission system including a plurality of multiplexing devices 51-i (i = 1 to 4) and a subscriber terminal at the end thereof, data input from the subscriber terminal is transmitted to each station. In such a system, when performing loopback control for each device, a unique code or bit corresponding to the loopback point is defined and transmitted. Was realized.

[0007] For example, consider a case where a loopback code (here, "0001") in the multiplexer 51-1 is defined. When the test pattern “0001” is transmitted from the test device 22 to the multiplexing device 51-1, the code “00”
The multiplexer 51-1 that has received "01" performs loopback control.

That is, at this time, the multiplexing device 51-1
The loopback control circuit 60 performs loopback control in the following manner. The loopback control code “0001” input from the test device 22 is identified by the loopback code identification unit 2 via the separation unit 1 and matches the defined code “0001”. Return to the upstream side through 5. On the other hand, if the identified loopback code does not match the defined code, it is sent to the subsequent device 51-2 as it is.

[0009]

However, in such a conventional loopback control system, when the same device is connected in a plurality of stages as described above, it is impossible to control the second and subsequent devices. Remote control is difficult.

On the other hand, when different codes are defined for each device, it is necessary to provide a circuit for detecting a different loopback code even if the devices have the same function. There was a problem that it was not possible to achieve this.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been developed in such a manner that even in a system in which the same device is connected in a plurality of stages, loopback control can be easily realized up to multiple relay destinations. It is intended to provide a control system.

[0012]

FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, reference numeral 1 denotes a separation unit, which separates input data into a main signal and a data link signal. It is. Reference numeral 2 denotes a loopback code identification unit. The loopback code identification unit 2 identifies a loopback code.

Reference numeral 3 denotes an arithmetic processing unit.
A predetermined operation is performed on the loopback code. 4
Is a multiplexing unit, and the multiplexing unit 4 multiplexes the main signal and the data link signal. 5 is a folding means,
The return means 5 sends the input data to the device back to the upstream device.

[0014]

According to the above-described loopback control system of the present invention, in a system in which the same device is connected in a plurality of stages,
In each of these devices, the received loopback code passes through the separation unit 1 and is identified by the loopback code identification unit 2. If the loopback code has a predetermined value, the loopback code is looped back to the upstream device via the loopback means 5 for looping the input data to the device.

On the other hand, if the identified loopback code is not a predetermined value, the arithmetic processing unit 3 performs a predetermined operation on the loopback code and sends the calculated loopback code to a subsequent device.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of the present invention. In FIG. 2, reference numerals 21-1, 21-2, 21-3 and 21-4 include a loopback control circuit 30 and function to multiplex data. A multiplexing device (MUX) having 2
Reference numeral 2 denotes a test device. The test device 22 sends a test pattern to each of the multiplexers 21-i (i = 1 to 4).

FIG. 3 is a block diagram showing a loopback control unit as a main part of one embodiment of the present invention.
The loopback control unit 30 shown in FIG. 1 includes a separation unit 1, a loopback code identification unit 2, an arithmetic processing unit 3, a multiplexing unit 4, a folding unit 5, interfaces 31, 33, and a control unit 32.

It should be noted that a separating unit 1, a loopback code discriminating unit 2, a multiplexing unit 4, loopback means 5, an interface 3
1, the control unit 32, and the interface 33 have already been described in the conventional example, and the description thereof will be omitted.
Here, the arithmetic processing unit 3 includes the loopback code identification unit 2
In this case, an operation for subtracting "1" from the loopback code is performed.

With the above configuration, the same multiplexer 21
In a system in which −i are connected in a plurality of stages, each of these devices performs a process as shown in FIG. First, in step A1, the loopback code in the data link is read, and then in step A2, it is determined whether or not the loopback code is "0001". If YE
If it is identified as S, loop back control is performed in step A4. On the other hand, in the case of NO, in step A3,
Subtract "1" from the loopback code and send it to the next stage.

That is, the multiplexer 21-1 includes a loopback control unit 30, and performs loopback control as follows. The input loopback code is identified by the loopback code identification unit 2 via the separation unit 1. If the identified loopback code is a predetermined value, the input data to the device is returned to the upstream device through the return means 5.

On the other hand, if the identified loopback code is not a predetermined value, a predetermined operation (operation of subtracting 1) is performed on the loopback code by the operation processing unit 3, and the loopback code after the operation is post-processed. To the device.

Accordingly, the multiplexers (MUX) 21-1, 21-2, 21-3, 21-4 having the same configuration as described above.
For example, when the loopback control is to be performed on the third multiplexing device in the system to which the.

As a result, the first multiplexer 21-
1 transmits the loopback code “0010” to the multiplexer 21-2 by subtracting 1 from the loopback code because the loopback code is not “0001”.

Similarly, the multiplexer 21-2 transmits the loop-back code "0001" obtained by subtracting 1 to the next multiplexer 21-3. Then, in the multiplexer 21-3, since the loop-back code "0001" matches the predetermined value, the multiplexer 21-3 receiving "0001"
Is connected to the upstream multiplexing device 21-
2 to perform loopback control to send data back to
reference).

Further, by setting another loopback code and sending it from the test device 22, loopback control can be performed on an arbitrary multiplexer. In this way, loopback control can be realized very easily up to multiple relay destinations.

[0026]

As described above in detail, according to the loopback control system of the present invention, in a system in which the same device is connected in a plurality of stages, the loopback code is identified by each of these devices, and then the arithmetic processing is performed. However, there is an advantage that loop-back control can be realized very easily to a multi-relay destination by transferring the data to a subsequent device.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a block diagram showing one embodiment of the present invention.

FIG. 3 is a block diagram showing a main part of one embodiment of the present invention.

FIG. 4 is a processing flowchart of a loopback control system.

FIG. 5 is a block diagram of a conventional loopback control system.

FIG. 6 is a block diagram showing a main part of a conventional loopback control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Separation part 2 Loopback code discrimination part 3 Operation processing part 4 Multiplexing part 5 Return means 21-1 to 21-4 Multiplexer (MUX) 22 Test apparatus 30 Loopback control part 31, 33 Interface 32 Control part 51- 1-51-4 Multiplexer (MUX) 60 Loopback controller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isamu Sekiguchi 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Akihiro Matsushita 1015, Kamodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor Hiroaki Takahashi 4-9-25 Shibaura, Minato-ku, Tokyo Shibaura Square Building Tokyo Communication Network Co., Ltd. (72) Inventor Masahiro Kobayashi 4-9-25 Shibaura, Minato-ku, Tokyo Shibaura Square Building Tokyo Communication Network Within the Company (72) Inventor Shinji Kiyota 4-9-25 Shibaura, Minato-ku, Tokyo Shibaura Square Building Tokyo Communication Network Company (56) References JP-A-55-105452 (JP, A) -180158 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 17/02 H04L 29/14

Claims (1)

(57) [Claims] In a system in which the same device is connected in a plurality of stages, each of these devices is identified by a loopback code identification unit (2) for identifying a loopback code, and a loopback code identification unit (2). When the obtained loopback code is a predetermined value, means for returning the input data to the device to the upstream device (5), and the loopback code identified by the loopback code identification unit (2) is the predetermined value. If it is not a value, an operation processing section (3) is provided, which performs a predetermined operation on the loopback code and sends the operated loopback code to a subsequent device.