JPH02155338A - Data transmission system - Google Patents

Abstract

PURPOSE:To offer accurate information for a job such as fault analysis by superimposing time information representing a monitor information occurrence time by each slave station onto a transmission frame and sending the result to a master station. CONSTITUTION:A master station 1 sends transmission frames a1-aN in which slave stations 2 (1)-2 (N) are designated as addresses with a polling sequence. A transmission frame a1 is received by a reception section 4 of the slave station s (1), monitor information D1 is superimposed on the transmission frame a1 and time information c1 representing a monitor information occurrence time t1 is superimposed and the result is sent from a transmission section 7 and received by the master station 1. On the other hand, the transmission frame aK designating the address of the slave station 2(K) is received by the slave station 2(K), after time information c2 representing a time t2 and monitor information DK are superimposed, and the result is sent to the master station 1. An identification section 9 identifies monitor information sets D1, DK and times t1, t2 represented by the time information sets c1, c2 from the transmission frames a1, aK and a node of a slave station, the content of monitor information and history information (a) representing the time in the time information are outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmission system, and particularly to a data transmission system for transmitting monitoring information between a master station and a slave station connected in a loop.

[Conventional technology]

As shown in FIG. 3, this type of data transmission method uses monitoring information D1. DI+ are slave stations 22(1) and 22(K), respectively.
, the transmission frame 23 (1) carrying the monitoring information D+, D* from the slave stations 22 (1), 22 (K),
23(K) to the master station 21, and the transmission frame 23(1) from the master station 21.

23 (K) is received by the network monitoring device 24. The contents of the transmission frames 23(1) and 23(K) received by the network monitoring device 24 are stored as history information together with the monitoring information generation time! 24 and output from the network monitoring device 24.

In the conventional data transmission method, as shown in FIG. 4, monitoring information D1. Transmission frame 23(1) as the time of occurrence of DI
, 23(K) was received by the network monitoring device 24 at the time 'r, ,'r.

[Problem to be solved by the invention]

In the conventional data transmission method described above, the transmission frames 23fl) and 23(K) are transmitted by the network monitoring device 2.
Since the system adopts a method in which the times T + and T z received in 4 are regarded as the generation times of the monitoring information D+ and Dx, there are the following drawbacks.

Due to the timing relationship between the polling from the master station 21 to the slave stations 22(1) and 22(K) and the times when the monitoring information D+ and Dx occur, the order of the actual times when the monitoring information D+ and DK occur may be out of order. Put it away.

That is, in FIG. 3, first, time 1. Child station 22 (1)
Monitoring information is generated at 1° (L+
When monitoring information DK occurs in slave station 22 (K) at z), the transmission frame 23 (from 11) from slave station 22 (K) is transmitted from slave station 22+11 due to the relationship surrounding polling As shown in FIG. 4, the H layer information includes the monitoring information t[J D
'gThe time information T is recorded as the time of occurrence, and the slave station 2
The time information Tz is used as the time of occurrence of the monitoring information D1 in 2(1).
(Tt >Tt) will be recorded.

As a result, the occurrence time will be reversed, causing trouble in fault search based on the historical information fIJb.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data transmission system that can solve the above problems and provide accurate information for tasks such as failure analysis.

[Means to solve the problem]

In the present invention, a slave station connected in a loop with a master station sends monitoring information of a white child station to a transmission frame sent from the master station by a boring sequence, and sends it back to the master station. A data transmission method in which a network monitoring device that receives a transmission frame outputs history information displaying monitoring information and time information of a slave station, wherein the slave station displays the monitoring information occurrence time along with the monitoring information of the white station. The network monitoring device is characterized in that the network monitoring device identifies the monitoring information and time information of a plurality of transmission frames, and forms and outputs the history information.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a data transmission system according to an embodiment of the present invention.

In the data transmission method of this example, each slave station 2(1) to 2(N) adds monitoring information and time information to a transmission frame transmitted from the master station 1 using a polling method, and transmits it to the master station 1. This is a method in which history information is output from the network monitoring device 3.

The master station 1 sends each slave station 2 (1) according to the boring sequence.
This station transmits a transmission frame specifying the address to slave stations 2(1) to 2(N) and collects monitoring information generated at slave stations 2(1) to 2(N).

The slave station 2 (11 (~2(N)) includes a receiving unit 4 that receives transmission frames from the master station, and generates monitoring information in the event of a failure and places the monitoring information on the transmission frame received by the receiving unit 4. A monitoring information generating section 5, a time information generating section 6 which adds time information indicating the time at which the monitoring information was generated to a transmission frame from the monitoring information generating section 5, and a time information generating section 6 which transfers the transmission frame from the time information generating section 6 to other slave stations. The 9-time vtf1 generation unit 6, which includes a transmitter 7 that transmits data to It has a function to put that time information on.

In the network monitoring device 3, the master station 1 and the slave stations 20) to 2(
A transmitting/receiving section 8 receives the transmitting frame received from the transmitter/receiving section 8 from the master station 1 and transmits the history information of slave stations 2(1) to 2(N) to the master station 1; Identification unit 9 that identifies monitoring information and time information and forms history information
It is equipped with In addition, the network monitoring device 3 periodically controls and updates the time managed by each slave station 2(1) to 2(N), and prevents the time difference between each slave station 2(I) to 2(N). It also has the function of preventing occurrence.

Next, the operation of the data transmission system of this embodiment will be explained. However, monitoring information D+ at slave stations 2 (1) and 2 (to)
When Dx occurs and the monitoring information at slave station 2 (1) is 8 occurrence time t1, the time t1 when Dx occurs and the monitoring information at slave station 2 (K) occurs is t.
This will be explained assuming that it is faster than 2.

From master station 1, slave station 2 (1) ~ according to the boring sequence
2(N) are respectively addressed.
9 is sent.

The transmission frame a1 is received by the receiving unit 4 of the slave station 2(1) and input into the monitoring information 5.

The monitoring information generating section 5 adds the monitoring information tFJ o + to the transmission frame a1 in which the Shiroko station is addressed, and outputs it to the time information generating section 6.

The transmission frame a1 input to the time information generating section 6 includes:
Time information fOc indicating the time when the monitoring information was generated.

is carried.

The transmission frame a from the time information generating section 6 is transmitted by the transmitting section 7.
and received by the master station l.

The transmission frame a received by the master station I is sent to the network monitoring device 3 and reaches the identification section 9 via the transmission and reception section 8.

On the other hand, the transmission frame ag specifying the address of the slave station 2 (K) is received by the slave station 2 (K), and the time information generator 5 generates the monitor information fIDK at the time t2.
After time information c2 indicating the time is loaded, it is sent to the master station 1.

The transmission frame aK received by the master station 1 is sent to the node work monitoring device 3 and reaches the identification section 9 via the transmission/reception section 8.

The network monitoring device 3 that has received the transmission frames a, , ag outputs the history information 11a shown in FIG. 2 when outputting the history information.
form and output.

That is, the identification unit 9 extracts the monitoring information f from the transmission frames a, , ag.
Time 1, . . , indicated by Do+, Dx and time information cl, c2. 1
．． and indicates the time of the slave station node, content of monitoring information 1 time information (2(x), D,, t, )
.

The history information a formed in (2(2), DK, t2) is output.

As a result, history information a includes each slave station 2 (11, 2(K
) Actual monitoring information generation time 1. ．． 1. is displayed, the network monitoring device 3 outputs accurate history information a that is unrelated to the reception time of the transmission frame aI+aK at the network monitoring device 3.

[Effects of the Invention] As explained above, the data transmission method of the present invention employs a method in which each slave station transmits time information indicating the time when monitoring information was generated to the master station in a transmission frame. The network monitoring device is notified of the exact time of the occurrence of the error, which has the effect of providing accurate information for tasks such as failure analysis.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a data transmission method according to an embodiment of the present invention, FIG. 2 is a diagram showing history information output from a network monitoring device used in the data transmission method of FIG. 1, and FIG. Figure 4 shows the conventional data transmission method, and Figure 3 shows the conventional data transmission method.
FIG. 3 is a diagram showing history information output from a network monitoring device used in the data transmission method shown in the figure. ■...Master station 2(1) to 2(N)...Slave station 3...Network monitoring device 5...Monitoring information generation unit 6...Time information generation Part 9: Identification part

Claims (1)

[Claims] (1) A slave station connected in a loop with a master station sends the transmission frame sent from the master station through a boring sequence with its own monitoring information back to the master station. A data transmission method in which a network monitoring device that receives a transmission frame outputs history information that displays monitoring information and time information of a slave station, wherein the slave station displays the monitoring information generation time as well as the monitoring information of its own slave station. time information indicating a plurality of transmission frames is placed on the transmission frame, and the network monitoring device is characterized in that it identifies monitoring information and time information of a plurality of transmission frames and forms and outputs the history information. Data transmission method.