JPH0490643A - Loop configuration controller - Google Patents

Abstract

PURPOSE:To confirm the operation of a monitoring timer by providing a function continuing abnormality vanishing a frame and a token from a loop-shaped communication line for more than prescribed time to perform a test for a timer. CONSTITUTION:A main station 1 and plural slave stations 2 are connected from a loop transmission path 3 in construction. The main station 1 and the slave stations 2 function as the loop construction controller controlling a loop- shaped line network by the loop transmission path 3 at all times. In this case, by arbitrarily continuing the abnormality vanishing the data frame and token on the transmission path 3 at least for more than one data frame time, a monitoring timer 6 of the slave stations 2 is started and operated to perform a function test for the monitoring timer 6. Thus, the operation of the monitoring timer 6 is confirmed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a signal transmission system for an information processing device, and in particular, to a signal transmission system for an information processing device, and particularly to a signal transmission system for a local area network configured by a loop-shaped line network.
The present invention relates to a loop configuration control device in a signal transmission system of an information processing device using a network or the like.

[Prior Art] As a conventional technology related to a signal transmission system for an information processing device, the technology described in, for example, Japanese Patent Application Laid-Open No. 117435/1983 is known.

In this type of conventional technology, a communication network is constructed by connecting one main station and a plurality of slave stations, each of which is an information processing device, to a loop-shaped communication line, and the control device of each station is connected to the If an abnormality occurs due to loss of transmission frames or tokens when transmitting or receiving signals on the line,
By providing a monitoring timer that detects that the abnormality has continued for a predetermined period of time or more, and a switching circuit that directly connects the input side and output side of the line based on the detection output of this monitoring timer, This allows for avoidance.

[Problems to be Solved by the Invention] The above-mentioned prior art does not take into consideration the function test of a monitoring timer that detects when an abnormality such as disappearance of frames, tokens, etc. continues for a predetermined period of time or more. This has the problem that an abnormality occurs in the loop transmission system that is actually connected in a loop, making it impossible to check the operation of the monitoring timer.

An object of the present invention is to provide a function to test a timer by causing an abnormality that causes frames and tokens to disappear from a looped communication line to continue for a predetermined period of time, thereby making it possible to check the operation of a monitoring timer. The purpose of the present invention is to provide a loop configuration control device that can perform the following steps.

[Means for Solving the Problems] According to the present invention, the object is to insert shift registers corresponding to the number of bits in the first field of a data frame by a switching signal from an external switch or software when the test function of the monitoring timer is activated. , The received data is serial-parallel converted for the number of bits, and the first field is detected by comparing all the bits of the first field of the data frame at once, and when the first field is detected, Do not transmit that data frame downstream and instead use bit binary 01
1 or a data frame that is different from the normal data frame format, and similarly, when the end field of the data frame is detected, the above-mentioned transmission is terminated. This is achieved by erasing data from the transmission path.

[Function] The monitoring timer can be activated and operated by arbitrarily continuing the abnormality that causes data frames and tokens to disappear on the transmission path for a length of at least one data frame, and this allows the monitoring timer to be functionally tested. It becomes possible to do this.

[Embodiment] Hereinafter, an embodiment of the loop configuration control device according to the present invention will be described in detail with reference to the drawings.

Fig. 1 is a block diagram showing an example of a loop-shaped line network to which the present invention is applied, Fig. 2 is a main block diagram showing the configuration of an embodiment of the present invention, and Fig. 3 is the structure of data frames and tokens. FIG. 4 is a block diagram showing the detailed configuration of an embodiment of the present invention, FIG. 5 is a timing chart explaining the operation, and FIG. 6 is a diagram showing various types of controls for the embodiment of the present invention. FIG. 3 is a diagram showing truth values. 1, 2, and 4, l is the main station, 2 is the slave station, 3 is the loop transmission path, 5 is the frame detection section, 6 is the monitoring timer, 7 is the data processing section,
8 is a data transmission control section, 9 is a data erasing section, and 10 is a delay switching section.

As shown in FIG. 1, the loop-shaped line network to which the present invention is applied includes a main station 1 and a plurality of slave stations 2 connected by a loop transmission line 3. The master station 1 and the slave station 2 function as a loop configuration control device that constantly controls the loop network through the loop transmission line 3.

The main part of one of the slave stations 2 according to the present invention is shown in FIG. 2, and the configuration control device in this slave station 2 will be described below with reference to FIG. 2.

The illustrated configuration control device includes a frame detection unit 5, a monitoring timer 6
, a data processing section 7, a data transmission control section 8, a data erasing section 9, and a delay switching section 10.

In the slave station 2, when a data frame is input from upstream through the loop transmission line 3, the frame detection unit 5
The data frame is detected, and when detected, the monitoring timer 6 is reset. This monitoring timer recognizes that a frame has disappeared from the loop transmission path 3 or has detected an abnormal data frame by not being reset by the frame detection section 5 for a predetermined period of time or more, and then sends the monitoring timer to the data processing section 7. If a data frame recognized as abnormal operation is received after reporting this, the data frame is passed to the data processing unit 7.

Further, the data transmission control unit 8 performs operations to secure and release tokens during normal operation, and to release tokens during abnormal operation.

The data erasing section 9 and the delay switching section 10 are according to the present invention, and by passing through these parts, data frames are erased from the loop transmission path.

Before explaining the present invention in detail, the structure of data frames and tokens transmitted on the loop transmission path 3 will be explained.

The data frame transmitted on the loop transmission line 3 is
As shown in figure (a), start delimiter (SD) 10
1. Access control (AC) 102, frame control (FC)
) 103, destination address (DA) 104, source address (SA) 105, information (INFO)
106, frame check sequence (FCS) 107
, an end limiter (ED) 108, and a frame status (FS) 109. The token also has a start delimiter (S) as shown in Figure 3(b).
D) 1o1.7'7-1! , Z, control (AC) 102,
and an end limiter (ED) 108.

The data frame and token are Non-Data11J''110 of the differential Manchester code.
, Non-Da t, a "K" 111, binary "O" 112, and binary "'l" 113. These differential Manchester codes "J"K II '1""0" are As shown in FIG. 6(a), it can be represented by two bits: [)ata and Non-Data.

Details of the portion of the loop configuration control device shown in FIG. 2 according to the present invention are shown in FIG. 4, and will be described below.

In FIG. 4, the data frame input from the loop transmission line 3 has the Manchester code '' of the frame.
J”K” “1” “O” is the encoding circuit 20
1, Data a, Non-D shown in FIG. 6(a)
This Da t is sequentially converted into 2 bits of a t a
a, Non-Data 8-bit signal is 8
A bit serial/parallel converter 202 converts it into 8-bit parallel data. This converted 8-bit parallel data is given to a start delimiter detector 203 and an end limiter calibrator 204, and SD and ED within the data frame are detected. Detection of the start delimiter SD and end delimiter ED is performed based on truth values as shown in FIG. 6(b).

In the timing chart shown in FIG. 5 for explaining the operation of the embodiment of the present invention shown in FIG. 4, when the start delimiter detector 203 detects the start delimiter SD, the start delimiter test signal shown in FIG. can be obtained. This start delimiter detection signal is delayed by 3 bits by delay circuit 205 and sets data erase signal generation flip-flop 207.

On the other hand, the received data frame whose SD and ED have been detected is simultaneously delayed by a total of 10 bits by the 8-bit delay circuit 208 and the 2-bit delay circuit 209, and then sent to the data eraser 9. It will be entered.

As a result, the data erasing signal 219 output from the flip-flop 207 reaches the data erasing unit 9 when it matches the beginning of the start delimiter SD of the received data obtained by delaying the data frame shown in FIG. 3(a) by 10 bits. This makes it possible to erase the data frame from the beginning of the start delimiter SD.

Similarly, when the end limiter detector 204 detects the end limiter ED of the data frame, it generates an end limiter detection signal as shown in FIG. This end limiter detection signal is delayed by 11 bits in delay circuit 206. As shown in FIG. 5, the time position of this delayed signal is located at the next bit position of the end limiter ED of the data frame obtained by delaying the received data frame by 10 bits.

Therefore, by resetting the flip-flop 207 and terminating the data erase signal by the end limiter detection signal delayed by 11 bits, it is possible to terminate the data erase signal at the end of the end limiter ED.

The data erasing section 9 erases the data frame using the data erasing signal 219 generated as described above. That is, the data erasing section 9 outputs the 10-bit delayed Data and Non-Data to the delay switching section 1o if the data erasing signal 219 is "0" according to the truth value shown in FIG. 6(C). However, the data erase signal 219 is “1”.
”, Fill (bit binary par 0 or “1”) is output as output Data, and pit binary “0” is output as output Non-Data.

The delay switching unit 10 performs selection control as to whether or not to erase a data frame according to the truth value shown in FIG. 6(d) in response to instructions from the delay switching signal 222. That is, when the delay switching signal 222 is "OI+", the delay switching section 10 converts the 2-bit delayed Data 217 and the 2-bit delayed Non-Data 218 into data after the data transmission control section 8 performs data control as in the conventional manner. Further, when the delay switching signal 222 is tt 1 n, Data 220 and Non-Data 221 that have passed through the data erasing section 9 are selected and output to the decoding circuit 212. Composite circuit 21
2 decodes the above-mentioned two given signals, converts them into differential Manchester codes, and sends them to the loop transmission line 3.
Send to.

According to one embodiment of the present invention described above, the delay switching signal 22
2 in 'l', that is, frame erase mode, the master station 1 or slave station 2 resets the monitoring timer 6 when receiving the first data frame,
From the start delimiter SD to the end delimiter ED of that frame, Fll is transmitted and the loop transmission line 3
It is possible to erase the data frame from above and cause the transmission abnormality to continue for a predetermined period of time or more. According to an embodiment of the present invention, the operation of the monitoring timer 6 can be confirmed,
Furthermore, unnecessary data frames can be deleted and the loop transmission path 3 can be cleaned.

[Effects of the Invention] As explained above, according to the present invention, in a loop transmission system, it is possible to erase from the loop from the first field to the end field of a transmission frame transmitted from upstream. Continuing the above,
It is possible to check the operation of the monitoring timer, and
It is also possible to clean the loop transmission path by erasing unnecessary data frames.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a loop-shaped line network to which the present invention is applied, Fig. 2 is a main block diagram showing the configuration of an embodiment of the present invention, and Fig. 3 is the structure of data frames and tokens. FIG. 4 is a block diagram showing the detailed configuration of an embodiment of the present invention, FIG. 5 is a timing chart explaining the operation, and FIG. 6 is a diagram showing various types of controls for the embodiment of the present invention. FIG. 3 is a diagram showing truth values. 1...Main station, 2...Slave station, 3...
...Loop transmission line, 5...Frame detection unit, 6
...Monitoring timer, 7...Data processing unit, 8...Data transmission control unit, 9...Data erasing unit, 10... Delay switching section. Figure 1 Figure (a) (b) Figure (b) Figure (C) (d)

Claims (1)

[Claims] 1. In a signal transmission system equipped with a loop-shaped transmission path, a device connected to the system recognizes the start field and end field of a received data frame, and connects the signal transmission path from the start of the start field to the end of the end field. What is claimed is: 1. A loop configuration control device characterized by having a test function for causing an abnormality in a loop transmission path for a certain period of time by erasing the error from the loop transmission line, and confirming processing in the event of a failure.