JPH0130336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information transmission method for transmitting information between a plurality of devices via a transmission path. The purpose of the invention is
An object of the present invention is to provide an information transmission method that allows a test to be performed without specifying the address of a receiving device.

Hereinafter, in the present invention, a transmission control device (Network Control Processor, hereinafter referred to as NCP) is placed on two loop lines that perform transmission in opposite directions to each other on a one-to-one basis with an NCP on a different loop line.
Let us take as an example the case of detecting an abnormality in the transmission path and detecting the abnormal location in a double loop transmission system in which each pair of NCPs is arranged so as to correspond to the above, and each pair of NCPs is connected by a bidirectional loop link line.

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, a loop formed only by loop lines, that is, a loop that goes around the loop line is formed by two adjacent NCP pairs of the large loop and the medium loop,
A loop in which data passes through the above two sets, that is, four NCPs, is called a small loop. Hereinafter, the present invention will be explained in detail by way of examples with reference to the drawings.

FIG. 1 shows an example of the basic configuration of the device according to the present invention, and includes loop lines L0, L1, and NCP01 to NCP01.
0n and 11 to 1n and the loop link line 21
~2n and terminal link lines 31 and 32, and a test terminal 30.

Next, Figure 2a shows an example of the frame structure of transmitted data, where FC is a function code.
A code corresponding to the content of the data that follows is attached. Note that FIG. 5B 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 interfaces for exchanging data with each terminal link line 31, 32, 320 is an input device, 321 is an output device, and 330 is a A receiving buffer, 331 a transmitting buffer, 340 a timer, and 341 to 343 registers.

Also, Figure 4 shows NCP01~0n and 11~1n
For example, an example of the block configuration of NCP01 is shown, and 40
is a processing unit, 51 to 54 are interfaces for transmitting and receiving data with the line, 51 is a bidirectional interface for the terminal link line, 52 is a bidirectional interface for the loop link line, and 53 and 54 are for the loop line. It is a unidirectional interface. Also, 61 is a receiving buffer, 62 is a transmitting buffer, and 70
and 83 are counters, 71, 72 and 81, 82 are registers, 73 is a memory, and 80 is a timer.

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

(1) Test start When a test start signal is input from the 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

The interface 310 or 311 of the line specified in the register 342 is the transmission buffer 33
Send the data in 1 to NCP01 or 11,
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, and a flag indicating the reception line is set in the register 341. Processing device 300
is the output device 321 for receiving data and receiving line number.
Output to.

(3) End of test Processing device 300 uses timer 340 and register 3
43, and if the contents match, and if a termination command is input from the input device 320, a test termination command is created and sent from the interface 310 or 311 to NCP01 or 11. Send.

Next, we will explain the transmission/reception processing operation in NCP0 to NCP0.
1 will be explained 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 the register 7.
A flag indicating the receiving line is set to 1. The processing device 40 converts the function code FC of the received data into
The code table stored in the memory 73 in advance is compared with the contents of the register 71 (receiving line number) to decide how to process the received data.
Process.

(2) Transmission processing When data to be transmitted occurs, the processing device 4
0 sets a flag specifying the transmission line in the register 72 and stores the transmission data in the transmission buffer 62. Next, the contents of the register 72, that is, the interface 5 corresponding to the designated line.
1 to 54 transmits the data in the transmission buffer 62 to the line.

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

The NCP that received the data checks the contents of the memory 73 and the function code FC of the received data.
If it determines that this is a test start command, it creates loop check data in the configuration shown in FIG. 2b and transmits it to the loop line L0 or L1 to which it belongs. In Fig. 2b, FC is a function code, that is, in this case, a function code indicating that the data is medium loop check data, N is a parameter indicating the size of the medium loop to be checked, and CN
is a count value that adds up the number of NCPs that this data has passed through, and the initial value is 1. In addition, the flag (flag) is set in 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 NCP01. The form of check data used to test middle loops 0-i and 1-i is FC|i|CN|0, and CN is incremented by 1 each time it passes through one NCP, as described above. The ● mark inside the Γ mark indicating NCP is
Indicates the starting point from which check data is created and transmitted.

Regarding this middle loop check method, the following 2
The method of two embodiments is shown.

Method 1: In this method, the NCP (hereinafter referred to as the test start NCP) that receives a test start command from the test terminal creates all medium loop check data and sends it to the loop line to which it belongs.

FIG. 6a shows middle loop check paths 0-1 and 0-2 in which NCP01 is the test start NCP, as an example of the middle loop check according to this method. Note that the path indicated by the broken line is the flow of check data. Also, the numbers (1, 1), (1,
2) ... is the N (loop size) and CN (the NCP routed) of the check data transmitted in that part.
number). 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 puts the value of N (=1) into the counter 70, creates medium loop check data FC|1|1|0, and transmits it to the neighboring NCP via the loop line to which it belongs. At the same time, 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 waiting to be 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).

The processing device 40 of the NCP that has received the middle loop check data performs arithmetic judgment based on N and CN of the received data, and performs the following processing.

(1) When CN=N Compare 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 change the value of CN by 1. The increased check data is sent to the paired NCP via the loop ring line.

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

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

(3) When CN=2N+2: Check the contents of the counter 70 and the value of N in the check data. (a) If they do not match, it is determined that a transmission error has occurred in this check data and it is deleted. .

(b) If they match, send the data indicating that loop N is normal in this check data.
The check data is sent to the test terminal via the terminal link line, and it is checked whether a flag is set in the flag section of this check data.

If it is not set, the counter 70
is increased by 1, this value is set as the value of N, medium loop check data FC|N|1|0 is created, and it is transmitted to the loop line to which it belongs. At the same time, the timer 80 is reset.
Counter 83 is cleared.

If the flag is set, new medium loop check data is not created, but data indicating that the test has completed normally 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 applies: The medium loop check data with the CN of the received data incremented by 1 is sent to the adjacent data through the loop line.
Send to NCP.

Timeout judgment: The NCP that sent the middle loop check data
If the transmitted check data is not returned within a predetermined time, it is determined that it has timed out and retransmission is performed. 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 a timeout 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 is previously stored.

(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 counter 70
, and data indicating abnormal termination are created and sent to the test terminal via the terminal link line, and the counters 70 and 83 are cleared.

(2) They do not match (the former is smaller than the latter)
In this case, medium loop check data FC|N|1|0 is created with the value in the counter 70 as N, and is retransmitted to the adjacent NCP via the loop line, the timer 80 is reset, and the counter 83 is incremented by 1. 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.

Hereinafter, the case where there are a plurality of test terminals in method 1 will be explained with reference to FIG. 6b.

In FIG. 6b, consider the case where NCPa and b perform a middle loop check. Here, middle loop check data a(n, m) is stored in the middle loop shown by the broken line.
and b(n, m) are assumed to flow. Note that a and b
indicates the source NCP. Further, as described above, n and m are check data N and CN, that is, a parameter indicating the size of the middle loop to be checked, and an integrated value of the number of NCPs through which the data has passed.

In the worst case, immediately after NCPb sends loop check data of size n, the loop check data of size n sent by NCPa becomes N.
When the check data is received by NCPb in the state of =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 the NCPa, the flag is set on the returned check data, so the NCPa does not create any larger medium loop 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,
When the test start NCP receives a test start command from the test terminal, it creates only medium loop check data of FC|1|1|0. Medium loop check data where N is 2 or more is created by the NCP on the loop line to which the test starting 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) uses the counter 7 as in method 1 above.
The content of 0 is set to 1, the timer 80 is reset, the counter 83 is cleared, and loop check data in FC|1|1|0 is created and transmitted to the adjacent NCP via the loop line.

The NCP that received the middle loop check data
The values of N and CN of the received check data are compared and the following processing is performed.

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

(b) If they match, set a flag in the flag section of the received check data, increment the value of CN by 1, and send it to the paired NCP via the loop link line.

(b) If the two do not match, increase the CN value of the received check data by 1 and connect the pair using the loop link line.
At the same time as transmitting it to the NCP, medium loop check data is created by incrementing the values of N and CN of the received check data by 1, and is transmitted from the loop line to the neighboring NCP.

(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 CN=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 section of the received check data.

If the flag is not set, the value of the received check data N 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 sent to the test terminal from the terminal link line, and the counter 7
Clear 0 and 83 (4) If the above (1), (2), and (3) do not apply, increase the CN value of the received check data by 1 and send it to the adjacent NCP via the loop line.

The test start NCP is set until the value of the timer 80 matches the content of the register 81 that specifies the timeout time, CN = 2N + 2, and N = the content of the counter 70 (the value of N of the check data waiting to be received).
If no check data is received, it is determined that a timeout has occurred, and the same retransmission process as in method 1 is performed.

An example of the middle loop check using method 2 is shown in Figure 7a.
Shown below. In this case, NCP01 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. 7b.

In the worst case, when NCPb is waiting for the middle loop check data of N=n (the contents of the counter 70 is n), when the check data of the middle loop check starting from NCPa becomes N=CN=n and reaches NCPb, NCPb does not create new check data by receiving this check data. Therefore, NCPa can only receive medium loop check data up to NCPb. However, NCPb checks the middle loop after NCPb. Therefore, if the parts checked by each test terminal are combined, the entire area of the transmission system is covered and the entire area has been checked.

In this way, using either method 1 or method 2, if the transmission path is normal, all middle loop checks are performed, and all of the data is stored at the start of the test.
Sent from NCP to test terminal.

If there is a disconnection of the line or a failure of the NCP,
The middle loop check data that must pass through the abnormal location is not received by the test initiation NCP.

Also, in some NCP, calculation judgment processing of N and CN
Even if a CN's count-up processing is 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 is performed using one connected to the test terminal.
Both of the paired NCPs are used as the starting NCPs. Therefore, by knowing the reception line output from the test terminal, that is, the test start NCP and the value of N of the medium loop check that was performed normally or the value of N of the medium loop check that was found to be abnormal, the tester can check the transmission path. It is possible to detect the presence or absence of an abnormality and the location of the abnormality.

Next, the end of the test is determined by the timeout described in the test end operation (3) of the test terminal and the input device 32.
By inputting the end command from 0. At this time, the test terminal creates test termination command data in 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 counters 70 and 83.

As explained above, according to the embodiment of the present invention, (1) each NCP does not need to be addressed;

(2) Test terminals may be attached to any NCP pair.

(3) It can also be checked if there is an abnormality in the NCP's calculation/judgment processing or detour control processing.

(4) It is possible to not only determine whether there is an abnormality in the transmission path, but also to estimate the location of the abnormality.

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

It has many advantages, and its effects are significant.

According to the present invention, a test can be performed without specifying the address of a receiving device.

[Brief explanation of drawings]

Fig. 1 is a basic configuration diagram of the present invention, Figs. 2 a and b are explanatory diagrams showing an example of the structure of general data and check data to be transmitted, and Figs. 3 and 4 are diagrams of a test terminal and a transmission control device. The configuration diagrams illustrating each embodiment and FIGS. 5 to 7 are explanatory diagrams each showing an example of the configuration of an intermediate loop formed in a transmission path. 21~2n...Loop link line, 31, 32
...Terminal link line, 30...Test terminal, 01~
0n, 11-1n...Transmission control device, L0, L1
...Loop line.

Claims (1)

[Claims] 1. Two loop lines that transmit data in opposite directions, transmission control devices installed in pairs on the two loop lines, and bidirectional data transmission between each pair of transmission control devices. In a data transmission system comprising a ring line, a test terminal is provided corresponding to at least one of the transmission control devices, and a check signal is transmitted from at least one of the transmission control devices to the line. The transmission control device that has received the check signal relays the check signal, and the transmission control device corresponding to the terminal device monitors the response to the check signal according to the command from the test terminal, and An information transmission method comprising detecting an abnormality in at least a part of a path including the transmission control device and transmitting the detection result to the test terminal.