JPH066366A - Broken line detector in local area network - Google Patents

Abstract

PURPOSE:To detect accurately a disconnected part of a communication line interconnecting equipments while simplifying internal configuration of each equipment being a component of a LAN by using a circulation signal transmission means and a fault detection means so as to detect the presence of a disconnected line of the communication line. CONSTITUTION:A circulation signal transmission means allows a communication means to send a circulati signal returned to the equipment circulated through each equipment being component of the LAN at once at least within a prescribed period of time in an either equipment direction. Then a fault detection means detects it as a fault when the circulation signal is not detected by the communication means within a prescribed period of time. When the fault is detected, a notice command means sends a command signal for notice command to a drive means in each equipment being a component of the LAN in an either equipment direction. Upon the receipt of the notice command, the drive means in each equipment drives a fault notice means provided to each equipment to inform a fault of the communication line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnection detecting device provided in a local area network for detecting disconnection of a communication line.

[0002]

2. Description of the Related Art Conventionally, as a disconnection detecting device for a communication line in a local area network (hereinafter, simply referred to as LAN) of this type, for example, Japanese Patent Laid-Open No. 63-246 is known.
As disclosed in Japanese Patent No. 947, one device that configures a LAN continuously transmits a disconnection detection signal that returns to the device by going around each of the other devices and configuring the LAN. When each device that does not receive the above disconnection detection signal within a certain time, it judges that the communication line is disconnected and notifies this by an alarm device such as a buzzer or lamp provided in advance. It has been known.

[0003]

However, the above-mentioned conventional disconnection detecting device in a LAN is effective for identifying the disconnection point of the communication line, but in each of the devices constituting the LAN, Since it is necessary to provide a monitoring device including a timer or the like for monitoring whether or not the disconnection detection signal is received within a fixed time, the configuration of each device is complicated. Then, there is a problem that the cost of the entire system is increased due to this.

Therefore, the present invention provides a LAN in
It is an object of the present invention to provide a disconnection detecting device capable of accurately detecting a disconnection point of a communication line connecting the above-mentioned devices while simplifying the internal configuration of each device constituting the above.

[0005]

That is, the present invention, which has been made to achieve the above object, comprises a communication means for performing data communication with another device via a communication line, as illustrated in FIG. A local area formed by connecting a plurality of devices, each having an abnormality notifying unit for notifying the occurrence of an abnormality and a driving unit for driving the abnormality notifying unit in response to a notification command from the outside, in a ring shape by the communication line. A disconnection detection device provided in a network for detecting a disconnection of the communication line, and at least once within a predetermined time, a cyclic signal sent back to the device by making a circuit through each of the devices is sent from one of the communication means. A cyclic signal transmitting means for transmitting in the device direction, and an abnormality detection for detecting an abnormality when the cyclic signal transmitted by the cyclic signal transmitting means is not received by the communication means within a fixed time. Means and an instructing command means for transmitting a command signal for issuing an instructing command to the driving means in each of the devices from the communication means to one of the devices when the anomaly detecting means detects an anomaly. Characteristic LAN
The gist is the wire breakage detection device.

[0006]

In the LAN disconnection detecting apparatus of the present invention configured as described above, the cyclic signal transmitting means makes a loop of each device constituting the LAN and returns a reply to the apparatus at least once within a predetermined time. A cyclic signal to be transmitted from the communication means toward one of the devices. Then, the abnormality detection means detects an abnormality when the cyclic signal is not received by the communication means within a fixed time. Next, when the anomaly detection means detects an anomaly, the notification command means causes the communication means to transmit a command signal for issuing a notification command to the drive means in each device constituting the LAN in the direction of one device.

Then, in response to the notification command, L
Driving means in each device constituting the AN drives an abnormality notifying means provided in each device, and this abnormality notifying means notifies an operator or the like of an abnormality in the communication line. Here, the abnormality detecting means can detect an abnormality because if the communication line is broken somewhere, the cyclic signal is not received within a fixed time. Also, the disconnection point of the communication line can be specified
This is because, in the one device direction in which the command signal is transmitted, since the notification command is not transmitted to the device and the devices arranged next to the disconnection point of the communication line, the abnormality notification means of those devices is not driven. .

Therefore, it is possible to detect that the communication line is broken immediately before the device in which the abnormality notifying means does not operate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 2 is a schematic configuration diagram showing an overall configuration of a transport line 2 in a sewing factory that is integrally controlled by each component device of a LAN to which the present invention is applied.

The transport line 2 of the present embodiment shown in FIG. 2 is formed by arranging a plurality of stations 4 each provided with a sewing machine such as a sewing machine having different uses according to each process, and a workpiece to be sewn between arbitrary stations 4. The carrier 6 holding the is conveyed. The carrier 6 is carried on the main rail 8 in the direction of the arrow in FIG. 2, and is branched and carried from the main rail 8 to the corresponding horseshoe-shaped station rail 12 by a desired branching mechanism 10. Then, it is guided to a desired station 4, where the sewing work of the workpiece is performed. After that, the carrier 6 exits the station 4, joins from the station rail 12 to the main rail 8 again, and is transported to the station 4 where the next process is performed.

Next, FIG. 3 is a schematic configuration diagram showing the internal configuration of each electronic control unit constituting the LAN for controlling the transport line 2. As shown in FIG. 3 (A), the LAN in the carrier line 2 of the present embodiment includes one main controller 20 which is a control center of the carrier line 2 and a carrier line 2 in accordance with an instruction from the main controller 20. A plurality of control devices 22 for driving and controlling the various actuators provided to carry the carrier 6, which are connected to the optical fiber cable 24.
It is configured by connecting in a ring shape. And
Communication between the devices is performed in one direction indicated by the arrow of the optical fiber cable 24. Further, the control device 22 is provided for each station 4 shown in FIG.

Here, in this embodiment, the main controller 20 is constructed so as to also function as the disconnection detecting device of the present invention. The main controller 20 displays a keyboard 26 for inputting the processing conditions such as the number of lots of the workpiece to be sewn and the quantity per lot, the progress of the sewing processing work, and the like on the transport line 2. The display 28 is connected as an abnormality notification means of the present invention for displaying the abnormality.

The main controller 20 is an E / O converter for converting an electric signal into an optical signal for performing data communication with each controller 22 via the optical fiber cable 24, and the optical signal into an electric signal. A communication circuit 30 as a communication means of the present invention including an O / E converter for converting, and a keyboard 26.
And an input / output circuit 32 which is a well-known interface with the display 28 and serves as a driving means of the present invention, and various controls based on information from the communication circuit 30 and the input / output circuit 32, which are constituted by well-known CPU, ROM, RAM and the like. It is provided with a central processing unit (hereinafter, simply referred to as CPU) 34 that executes calculation, communication processing and the like.

In the present embodiment, the communication circuit 30 is composed of only the communication driver circuit, and all communication processing is performed by C.
The PU 34 may be configured to perform the communication, or the communication circuit 30 may be provided with a CPU different from the CPU 34 to perform the communication processing. Main controller 2 configured as described above
0 indicates that the optical fiber cable 2 is operated by the CPU 34.
Control of data communication performed via the control unit 4, processing conditions input from the keyboard 26, notification of carrying-in of the carrier 6 to the station 4 received by the communication circuit 30 and received by the communication circuit 30, each sewing operation. In accordance with the present invention, the integrated control of the carrier line 2 that grasps the processing status from the end notification of the carrier 6, the carry-out notification of the carrier 6 to the main rail 8, and the like, and transmits the carrier control data of the carrier 6 to each control device 22. The main function involved is detection of disconnection of the optical fiber cable 24.

On the other hand, as shown in FIG. 3B, each control unit 22 has an end switch 36 for notifying the main control unit 20 of the end of work at the station 4, and the branch mechanism 1.
0, various actuators 38 for transporting the transport body 6 by operating various mechanisms provided on the transport line 2 such as a transport chain (not shown), and an abnormality notifying means of the present invention for displaying an abnormality on the transport line 2. LED 40 and the like are connected.

Each control unit 22 is composed of the main control unit 2
An input / output circuit 44 as a driving means of the present invention, which is an interface between the communication circuit 42 similar to 0, the end switch 36, various actuators 38, the LED 40, etc., and is composed of a transistor, etc., and a well-known CPU, ROM, RA.
A central processing unit (hereinafter, simply referred to as a CPU) 46 configured by M or the like and performing various control processes and communication processes is provided. Then, by the function of the CUP 46, the transport control of the transport body 6 on the transport line 2 and the like are performed based on the communication processing and the transport control data transmitted from the main controller 20.

Hereinafter, in the LAN configured as described above, the optical fiber cable 24, which is the main processing executed by the CPU 34 of the main controller 20 in particular, is the main processing relating to the present invention.
The disconnection detection process of is described with reference to FIG. First, as a premise, in the LAN of the present embodiment, the device serving as the transmission source attaches an address previously assigned to itself to the data to be transmitted and transmits the data. Then, when each device receives the data, it captures the data in the internal memory, identifies the transmission source from the address, and determines whether or not the device has transmitted the data first. When it is determined that the source other than itself is the transmission source, this data is directly transmitted to the next device on the optical fiber cable 24. As a result, the signal sent to the optical fiber cable 24 from any device including the main control device 20 is surely passed through each device and returned to the device of the transmission source.

FIG. 4 is a flow chart for explaining the disconnection detection processing of the optical fiber cable 24, which is executed by the CPU 34 of the main controller 20. The main controller 2
In parallel with the disconnection detection processing shown in FIG. 4, the CPU 34 of 0 will receive data, receive data into the internal memory, determine the transmission source of the data, and receive data will be described later. When it is determined that the signal is a signal other than the transport control data and the inspection signal transmitted in S130 or S150 (a signal that the main control device 20 is not the transmission source), the received data is directly transmitted to the next control device 22 on the optical fiber cable 24. And a communication process (not shown) consisting of a transmission process for transmitting to

First, the CPU 34 of the main controller 20 starts an internal timer (not shown) when the power is turned on. Then, in S110, the transport control data for each control device 22 is processed and calculated based on the input information from the keyboard 26 and the received data from the communication circuit 30.

Then, in S120, it is determined whether or not there is transport control data to be actually transmitted (hereinafter, simply referred to as control data) as a result of the processing in S110. When it is determined that the control data is present, the process proceeds to S130 and the data is transmitted in S130.

On the other hand, when it is determined in S120 that there is no control data as a result of the processing in S110, the process proceeds to S140. In S140, it is determined whether or not a predetermined time T1 has elapsed from the value of the internal timer started when the power was turned on. When it is determined that the predetermined time T1 has not elapsed, the process returns to S110 and the above-described processing is repeated. Then, if there is control data within the predetermined time T1, this will be transmitted in S130.

When it is determined in S140 that the predetermined time T1 has elapsed, the process proceeds to S150, and in S150, the inspection signal of the optical fiber cable 24 which is not related to the transport control is transmitted. When the control data or the inspection signal is transmitted in S130 or S150, S16 is transmitted, respectively.
In step S160, the internal timer of the CPU 34 is restarted. Here, the internal timer is restarted so that when S140 is executed next time, it is possible to determine whether or not the predetermined time T1 has elapsed from the previous transmission of the control data or the inspection signal. This is also for measuring a predetermined time T2 described later.

In subsequent S170, S130 or S150.
Then, it is judged whether or not the transmitted control data or inspection signal is received by the communication circuit 30 of the main control device 20 after going around each control device 22, and when it is judged that the control data or the inspection signal is received, the process returns to S110. , The above process is repeated. As a result, the main controller 2 is at least once within the predetermined time T1.
The control data or the inspection signal is transmitted from 0 to each control device 22, and the processing of S160 and S170 is executed each time.

On the other hand, when it is determined in S170 that the transmitted control data or inspection signal is not received, S18
Move to 0. In S180, it is determined based on the value of the internal timer started in S160 whether or not a predetermined time T2 has elapsed from the transmission of the control data or the inspection signal executed in S130 or S150. Here, the predetermined time T
2 is set to be sufficiently smaller than the predetermined time T1 and slightly longer than the time for which the control data or the inspection signal goes around each device.

When it is determined in S180 that the predetermined time T2 has not elapsed, the process returns to S170 and waits for reception of the transmitted control data or inspection signal. When it is determined in S180 that the predetermined time T2 has elapsed, S19
0, and in S190, the fact that somewhere in the optical fiber cable 24 is broken indicates that the input / output circuit 3 of the main controller 20 has
2 is displayed on the display 28. Then, the process further proceeds to S200, and a command signal for turning on the LED 40 included in each control device 22 is transmitted to each control device 22.

Then, each control device 22 which receives this command signal drives each LED 40 by the input / output circuit 44 of each control device 22 to light it. That is, in this disconnection detection processing, S130 and S150 for transmitting the control data or inspection signal as the cyclic signal are the cyclic signal transmitting means of the present invention, S170 and S180 are the abnormality detecting means of the present invention, and S190 and S200 are Each functions as the notification instruction means of the present invention.

As described above, the disconnection point of the optical fiber cable 24 is specified. The reason why the disconnection point can be specified will be described with reference to FIG. For example, as shown in FIG. 5, 12 control devices 22 (22a, 22b, ..., 2)
2k, 22l), the control device 22g and the control device 2
It is assumed that the optical fiber cable 24 is broken (marked with X) between 2 h. At this time, the command signal transmitted by the main control device 20 is the control devices 22a, 22b, ..., 2 as shown by the arrows in FIG.
LED 40 (40
a, 40b, ..., 40k, 40l) should be turned on.

However, the control devices 22h, 22i, 22j, which are arranged after the disconnection point of the optical fiber cable 24,
22k and 22l cannot receive this command signal,
The LEDs 40h, 40i, 40j, 40k, and 40l remain off. That is, the disconnection of the optical fiber cable 24 can be visually detected at the boundary between the place where the LED 40 is turned on and the place where the LED 40 is turned off.

Further, for example, referring to FIG. 5, the main controller 2
When there is a disconnection between 0 and the control device 22a, only the display 28 notifies the disconnection, and when there is a disconnection between the control device 22l and the main control device 20,
All LEDs 40a, 40b, including the display 28,
.., 40k, 40l are lit, the disconnection location can be identified even in these cases.

As described above, in the LAN in the carrier line 2 of this embodiment, the main control unit 20 constituting the LAN performs the process for detecting the disconnection of the optical fiber cable 24 as the disconnection detecting device of the present invention, and other Each control device 22
However, the LED 40 provided for each of them is turned on in accordance with the command signal transmitted from the main control device 20 to display the disconnection point.

Therefore, it is not necessary to provide each control device 22 except the LED 40 for notifying the occurrence of the disconnection and its drive circuit as an additional device not related to the basic function. Simpler configuration. Also,
As a result, the cost of the entire system is kept low.

In the above embodiment, a signal sent from any device including the main control device 20 to the optical fiber cable 24 is surely circulated in one direction and returned to the device as the transmission source. Under this condition, the disconnection detection device in which the main control device 20 transmits the control data or the inspection signal at least once within the predetermined time T1 has been described, but at least the main control device 20 serves as a transmission source. Even in the LAN in which only the control data or inspection signal to be transmitted circulates each control device 22 in one direction and is returned to the main control device 20, the same effect as in the above embodiment can be obtained.

In this case, each control device 22 discriminates the control data or the inspection signal transmitted by the main control device 20 as a transmission source, and transmits it as it is to the next control device 22 on the optical fiber cable 24. You can do it like this,
There are no particular restrictions on the transmission direction of other data.

Further, the control data and the inspection signal are considered completely separately, and at least only the inspection signal transmitted by the main control device 20 circulates each device in one direction so that the main control device 20 periodically Even in the disconnection detecting device that transmits the inspection signal, the present invention can be applied to obtain the same effect as that of the above embodiment.

In this case, each control device 22 discriminates at least the inspection signal transmitted by the main control device 20 from the received data, and transmits it as it is to the next control device 22 on the optical fiber cable 24. Be sure to
For example, in the disconnection detection process executed by the CPU 34 of the main control device 20 shown in FIG. 4, the process immediately returns to S110 after execution of S130. Then, in S170,
It is only necessary to determine whether or not the inspection signal transmitted in S150 has been received.

[0036]

As described above, in the LAN disconnection detecting apparatus of the present invention, the presence / absence of disconnection of the communication line is detected by the cyclic signal transmitting means and the abnormality detecting means.
The notification command means gives a notification command to the drive means provided in each device constituting the LAN. Then, the drive means in each device that has received the notification command in this way drives the abnormality notification means provided in each device, and identifies the disconnection point of the communication line based on the operation status of the abnormality notification means.

Therefore, by using the disconnection detecting device for a LAN of the present invention, it is of course possible to accurately detect the disconnection point of the communication line connecting each device constituting the LAN, and it is possible to detect other than the above-mentioned predetermined one device. Each device does not need to be provided as an additional device that is not related to the basic communication function, other than a device for notifying the occurrence of disconnection, and the configuration of each device is simplified. Therefore, the cost of the entire system can be kept low.

Further, if the disconnection detecting device in the LAN of the present invention is provided in a predetermined one of the plurality of devices constituting the LAN as in the above-mentioned embodiment, the communication line can be more efficiently provided. The disconnection and its location can be detected.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing an overall configuration of a transfer line 2 in a sewing factory of an embodiment.

FIG. 3 is an LA for controlling the transfer line 2 of the embodiment.
It is a schematic block diagram showing the internal structure of each electronic control unit which comprises N.

FIG. 4 C of the main controller 20 in the LAN of the embodiment
It is a flowchart explaining the disconnection detection process of the optical fiber cable 24 performed by PU34.

FIG. 5 is an explanatory diagram illustrating that a disconnection point can be specified when a disconnection of the optical fiber cable 24 occurs in the LAN of the embodiment.

[Explanation of symbols]

2 ... Transport line 4 ... Station 6
... Conveyor 8 ... Main rail 10 ... Branching mechanism 12
... Station rail 20 ... Main controller 22 (22a, 22b, ..., 22k, 22l) ... Controller 24 ... Optical fiber cable 26 ... Keyboard 28 ... Display 30, 42 ... Communication circuit 32, 44 ... Input / output circuit 3
4, 46 ... CPU 36 ... End switch 38 ... Actuator 40 (40a, 40b, ..., 40k, 40l) ... LED

Claims (1)

[Claims] 1. A communication means for performing data communication with another device via a communication line, an abnormality notifying means for notifying occurrence of an abnormality, and a drive for driving the abnormality notifying means in response to a notification command from the outside. A plurality of devices each equipped with
A disconnection detection device provided in a local area network connected in a ring shape by the communication line, for detecting a disconnection of the communication line, the device being configured to go through each of the devices at least once within a predetermined time. The cyclic signal transmitted to the one device direction from the communication means, and when the cyclic signal transmitted by the cyclic signal transmission means is not received by the communication means within a fixed time, Abnormality detecting means for detecting an abnormality, and when the abnormality detecting means detects an abnormality, an informing instruction means for transmitting an instruction signal for issuing an informing instruction to the driving means in each of the devices from the communication means in one device direction. And a disconnection detection device in a local area network.