JPS60100852A - Transmission line test system - Google Patents

Abstract

PURPOSE:To attain detection of an abnormality of a transmission line as well as estimation of the abnormal area by arranging in 1:1 transmission controllers NCP on different loop circuits and using a bidirectional loop circuit to have connection between the NCPs of each pair. CONSTITUTION:NCP 01-0n and 11-1n having the same number of detecting functions for abnormal area on the transmission line are arranged on two loop circuit L0 and L1 which perform transmission in direction opposite to each other. Loop link circuits 21-2n connect two NCPs belonging to different circuits L0 and L1 to perform the bidirectional transmission. Terminal link circuits 31 and 32 connect a test terminal 30 to an NCP to perform the bidirectional transmission. Then the terminal 30 gives a command to the NCP 01 and 11 for detection and test of the abnormal area of the transmission line through circuits 31 and 32. At the same time, the terminal 30 can receive the test results from the NCP 01 and 11.

Description

[Detailed description of the invention] The present invention relates to a transmission path abnormality detection test method.

That is, the present invention installs a transmission control device (NetworkCon) on two loop lines that perform transmission in opposite directions.
Trol Processor (hereinafter referred to as NCP).

In a double loop transmission system where NC and P are placed in correspondence with each other on different loop lines, and each pair of N02 is connected by a bidirectional loop link line, an abnormality in the transmission line is detected. The purpose is to provide a method for detecting and detecting anomalies. Note that in the present invention, in any two NCP pairs, the loop line between the NCP pair and each N
Testing of loops formed by loop link lines between CP pairs and NCP pairs, and NC during transmission system construction etc.
This test method is characterized in that it is a test method when P is not addressed.

In the following, data transmitted through a loop link line will be referred to as a "detour", and a loop having two such detours will be referred to as a "middle loop".

In addition, it is formed only by loop lines, that is, the loop that goes around the loop line is formed by two adjacent NCP pairs of the large loop and the medium loop, and the data passes through the above two sets, that is, four NCPs. A loop that goes around once is called a small loop. Hereinafter, the present invention will be explained in detail by way of an embodiment with reference to the drawings. 6 Fig. 1 shows an example of the principle configuration of a device according to the method of the present invention, and shows loop lines LO, Ll, NCPOI-
On and 11~In and loop link lines 21~2n
and terminal link lines 31 and 32, and test terminal 3
Consists of 0.

Next, FIG. 2(a) shows an example of the frame structure of data to be transmitted, where FC is a function code (Function Code).
In e), a code corresponding to the content of the following data is attached. Note that FIG. 6(b) will be described later.

FIG. 3 shows an example of the block configuration of the test terminal 30, 300 is a processing device, 310 and 311 are each terminal link line 31.3
2 and an interface for exchanging data, 320 is an input device, 321 is an output device, 330 is a reception buffer, 3
31 is a transmission buffer, 340 is a timer, 341 to 343
is a register.

Also, Fig. 4 shows NCPOI-On and 1l-In, for example, N
An example of the block configuration of CPO1 is shown, 40 is a processing device, 5
1 to 54 are interfaces for transmitting and receiving data to and from lines; 51 is a bidirectional interface for terminal link lines;
52 is a bidirectional interface for loop link line, 5
3 and 54 are unidirectional interfaces for loop lines. Also, 61 is a reception buffer, 62 is a transmission buffer, and 70
and 83 are counters, 71.72 and 81.82 are registers, 73 is memory, and 80 is a timer.

Next, an outline of the operation of the test terminal 30 will be explained.

(1) When a test start signal is input from the test start input device 320, the processing device 300 creates a test start command for the NCP, stores it in the transmission buffer 331, and sets a flag specifying the transmission line in the register 342. stand on

Interface 31 of the line specified in register 342
0 or 311 means that the data in the transmission buffer 331 is
POI or 02, and at the same time timer 340 is reset.

(2) During the test period, when the test terminal 30 receives data from the terminal link lines 31 and 32, the data is stored in the reception buffer 330,
A flag indicating the receiving line is set in the register 341. The processing device 300 outputs the received data and the receiving line number to the output device 321.

(3) The test termination processing device 300 compares the contents stored in advance in the timer 340 and the register 343, and issues a test termination command when the contents match and when a termination command is input from the input device 320. Create and interface 3
10 or 311 to NCPOI or 11.

Next, the transmission/reception processing operation in NCP will be explained using NCPol as an example.

(1) Reception Processing When data is received by any of the interfaces 51 to 54 of the NCP, the received data is stored in the reception buffer 61, and a flag indicating the reception line is set in the register 71. The processing device 40 compares the function code FC of the received data with a code table stored in advance in the memory 73, determines the processing of the received data in conjunction with the contents of the register 71 (the number of the receiving circuit), and processes it.

(2) Transmission Process When data to be transmitted occurs, the processing device 40 sets a flag specifying a transmission line in the register 72 and stores the transmission data in the transmission buffer 62. Next, one of the interfaces 51 to 54 corresponding to the contents of the register 72, that is, the designated line, transmits the data in the transmission buffer 62 to the line.

The operation of each part in the method of the present invention will be explained below.

Upon receiving the data, the NCP compares the contents of the memory 73 with the function code FC of the received data and, if it determines that this is a test start command, creates middle loop check data with the configuration shown in Figure 2(b). and transmits it to the loop line LO or Ll to which it belongs. In FIG. 2(b), FC is a function code, that is, in this case, a function code indicating that the data is middle loop check data, N
is a parameter that indicates the size of the middle loop to be chinked.

CN is a count value that adds up the number of NCPs through which this data has passed, and its initial value is 1. Also, flag
at the NCP connected to the test terminal.

Set when N=CN is received.

FIG. 5 shows an example of the configuration of the middle loop starting from NCPO1. The form of check data for testing middle loops O-i and 1-4 is incremented by l each time it passes through one NCP. Note that the mark inside the O symbol indicating the NCP indicates the starting point from which check data is created and transmitted.

Two embodiments of this middle loop check method will be shown below.

Method 1: In this method, the NGPC (hereinafter referred to as the test start NCP) that receives the test start command from the test terminal creates all medium loop check data and transmits it to the loop line to which it belongs. - FIG. 6 (8) shows middle loop check routes 0-1 and Q-2 in which the test start NCP is the NCPOI as an example of the middle loop check using the 1-bokuto method.

Note that the route indicated by the broken line is the flow of check data. Also, the numbers (1, 1), (1°2), etc. written on the broken line are
. . . is the check data N(
(loop size) and CN (number of NCPs traversed). The middle loop check data transmission control according to method 1 will be described below.

When the test start NCP receives the test start command, it starts the counter 7.
The value of N (=1) is entered in 0, and the loop line to which the middle Loubuch belongs is used to send a call to the neighboring NCP, the timer is reset, and the counter 83 is cleared. Note that the value in the counter 70 is the size of the middle loop being tested, that is, the value of N of the middle loop check data that is being received, and the timer 80 is used to measure the time since the check data is transmitted. When the check data does not return within a predetermined time, the counter 83 counts up and records the number of retransmissions when the same check data is sent again (retransmission).

Processing device 4 of the NCP that received the middle loop check data
0 performs calculation and determination based on N and CN of the received data, and performs the following processing.

(1) When CN=N: Check the contents of the counter 70 and the value of N in the check data. (a) If they match, set a flag in the flag section of the check data and set the value of CN to 1. The check data increased by the amount is sent to the paired NCP through the loop ring line.

(b) If they do not match, medium loop check data with the CN value incremented by 1 is transmitted to the paired NCP through the loop ring line.

(2) When CN=2N+1: Send medium loop check data with the CN of the received data increased by 1 to the paired NCP through the loop ring line.

(3) When CN=2N+2: Compare the contents of the counter 70 with the value of N in the check data.

(b) If they do not match, it is determined that a transmission error has occurred in this check data, and the check data is deleted.

(b) If they match, send data indicating that loop N in this check data is normal to the test terminal via the terminal link line, and check whether a flag is set in the flag section of this check data. Find out whether or not.

If it is not set, the counter 70 is incremented by 1, this value is set as the value of N, and a call is made to the loop line to which it belongs.

Note that the timer 80 is reset at the same time.

Counter 83 is cleared.

If the flag is set, new middle loop check data is not created, but data indicating that the test has completed successfully is created and sent to the test terminal via the terminal link line, and counters 70 and 83 are cleared. do.

(4) If none of the above cases apply: Medium loop check data in which the CN of the received data is increased by 1 is transmitted to the adjacent NCP through the loop line.

Timeout determination: The NCP that transmitted the medium loop check data determines that the transmitted check data is timed out if it does not return within a predetermined time, and retransmits the data. A timeout is determined by comparing the contents of a register 81, in which a predetermined time value is stored, with the contents of a timer 80, and if the latter is greater than the former, a timeout is determined.

Retransmission processing: When time error 1~ is determined, the following retransmission processing is performed.

A counter 83 that records the number of retransmissions performed for medium loops of the same size is compared with the contents of a register 82 in which the maximum number of retransmissions has been stored in advance.

(1) If both match, it is determined that there is an abnormality in the middle loop whose size is the value (N) in the counter 70, and the value in the counter 70 and data indicating that it has ended abnormally are created. and transmits it to the test terminal via the terminal link line, and also clears the counters 70 and 83.

(2) When the two do not match (the former is smaller than the latter).

The value in the counter 70 is set to N and is retransmitted to the neighboring NCP via the middle loop check line, the timer 80 is reset, and the counter 83 is incremented by one. This retransmission process is repeated until the retransmitted check data goes through a loop of size N and returns to normal, or until the abnormal termination as described in (1) above occurs.

Below, the case where there are multiple test terminals in Method 1 is explained in 6th section.
This will be explained with reference to Figure (b).

In FIG. 6(b), consider the case where NCPa and b perform a middle loop check. Here, the middle loop check data a(n) is shown in the middle loop indicated by the broken line.

Suppose that m) and b (n, m) flow. Note that a and b
indicates the source NCP. Further, as described above, n and m are the check data N and CN, that is, the integrated value of the parameter indicating the size of the middle loop to be checked and the number of NCPs through which the data has passed.

In the worst case, immediately after NCPb transmits the medium loop check data of size n, the medium loop check data of size n transmitted by NCPa is N = CN (=
n), a flag is set in this check data. As a result, when this check data goes around the path indicated by the broken line and returns to NCPa, NCPa does not create larger medium loop check data because the flag is set on the returned check data.

In this way, when tests are performed simultaneously by multiple test terminals, in the worst case, each test terminal may be able to test only part of the transmission system, that is, the middle loop up to the adjacent test terminals. When the parts tested by each test terminal are combined, the entire transmission system is covered and the entire test is performed.

Method 2: In method 1 above, all middle loop check data is created by the test starting NCP, but in method 2, the test starting NC
R receives the test start command from the test terminal and creates only the nick data. Medium loop check data where N is 2 or more is created by the NCP on the loop line to which the test start NCP belongs. For this purpose, the following processing is performed.

The NCP that received the test start command from the test terminal (test start NCP) sets the contents of the counter 70 to 1 as in method 1 above.
, resets timer 8o, and sends a call to the neighboring NCP.

The NCR that has received the middle loop check data compares the values of N and CN of the received check data and performs the following processing.

(1) When CN=N, compare the contents of the counter 70 with the value of N in the received check data.

(b) If both match, set a flag in the flag section of the received check data, increase the value of CN by 1, and connect the pair of N from the loop link line.
Send to CP.

(b) If the two do not match, increase the CN value of the received check data by 1 and send it to the paired NCR via the loop link line, and increase the N and CN values of the received check data by 1 each. Create loop check data and send it to the neighboring NCP from the loop line.

(2) If CN=2N+1, increase the CN value of the received check data by 1 and send it to the paired NCP via the loop link line.

(3) When C, N=2N+2, compare the contents of the counter 70 with the value of N in the received check data.

(b) If the two do not match, it is assumed that there is a transmission error and the received check data is deleted.

(b) If the two match, check the flag part of the received check data.

If the flag is not set, the value of N of the received check data is transmitted as data to the test terminal via the terminal link line, the counter 70 is incremented by 1, the timer 80 is reset, and the counter 83 is cleared.

If the flag is set, the N value of the received check data and data indicating that the test has completed normally are created and transmitted to the test terminal via the terminal link line, and the counters 70 and 83 are cleared.

(4) In cases where (1), (2), and (3) above do not apply,
The CN value of the received check data is incremented by 1 and sent to the adjacent NCP via the loop line.

The test start NCP waits until the value of the timer 80 matches the contents of the register 81 that defines the timeout time.
CN=2N+2. If the check data of N=the contents of the counter 70 (the value of N of the received check data) is not received, it is determined that there is a timeout, and the same retransmission process as in method 1 is performed.

An example of the middle loop check using method 2 is shown in FIG. 7(a). In this case, the NCPOI is the test starting NCP.

In method 2, the case where a plurality of test terminals are provided will be explained with reference to FIG. 7(b).

In the worst case, when NCPb has the middle loop check data of N=n (the content of the counter 70 is n), the NCP
The check data of the middle loop check starting from a is N
=CN=n and when NCP b is reached, NCP b does not create new check data by receiving this check data. Therefore, in NCPa, NCPb
Only the middle loop check data up to NCP,b can be received, but the middle loops after NCP,b are checked by NCPb. Therefore, if you combine the parts checked by each test terminal, the entire transmission system will be covered.
This means that a complete check has been carried out.

In this way, by either method 1 or method 2, if the transmission path is normal, all intermediate loop checks are performed, and all of the data is sent from the test starting NCP to the test terminal.

If there is a disconnection of the line or a failure of the NCP, the intermediate loop check data that must pass through the abnormality will not be received by the test starting NCP.

Further, even if the arithmetic determination processing of a certain NCP''rN and CN, the CN count-up processing, etc. are not performed normally, the middle loop check data that must pass through that NCP will not be received by the test starting NCP.

The middle loop check consists of a pair of NCs connected to the test terminal.
Both P are used as the test start NCP. Therefore, the tester can check the reception line output from the test terminal, that is, the test start NCP, and the N of the normal loop check, or the middle loop that was found to be abnormal. By knowing the value of N in the check, it is possible to detect the presence or absence of an abnormality in the transmission path and the location of the abnormality.

Next, the end of the test is performed by the test end operation (3) of the test terminal described above.
) and the termination command input from the input device 320. At this time, the test terminal creates test termination command data using the processing device 300, transmits this data to the NCP connected to the test terminal, and then stops. The NCP that receives the test end command data clears the counters 7o and 83.

As explained above, (1) Transmission path test method of the present invention (1) Each NCP does not need to be addressed.

(2) The test terminal can be attached to any NCP pair.

(3) It is also possible to check if there is an abnormality in the Ncp calculation determination process, detour control process, etc.

(4) It is possible to estimate not only the presence or absence of an abnormality in the transmission path, but also the location of the abnormality.

(5) Even if a temporary transmission error occurs due to noise or the like, it can be dealt with by retransmission processing.

It has many advantages, and its effects are significant.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the present invention, and FIGS. 2(a) and (
b) is an explanatory diagram showing an example of the configuration of general data and check data to be transmitted, FIGS. 3 and 4 are configuration diagrams showing each embodiment of the test terminal and transmission control device, and FIGS. 5 to 7 are Both are explanatory diagrams showing a configuration example of a middle loop formed in a transmission path. 21-2n...Loop link line, 3],, 32...Terminal link line, 30...Test terminal, O1-On, 11-In...Transmission control device, LO
, Ll...Loop line. group t ('b i2 group (a-) (each) E Ding Ding W] ward]]] 7 mouths 3 Zuei l Dangu I

Claims (1)

[Claims] Two loop lines that perform transmission in opposite directions, the same number of transmission control devices that are arranged on each of the above loop lines and have a transmission path abnormality detection test function, and two of the above transmission lines that belong to separate loop lines. The test terminal is equipped with a J-Lepe link line that connects the control device and performs bidirectional transmission, and a terminal link line that connects the test terminal and the transmission control device and performs bidirectional transmission. A transmission line testing method characterized by instructing the transmission control device to perform a transmission path abnormality detection test through a line and receiving test results from the transmission control device.