JP2001339415A - Conveyance system provided with network disconnection detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance system capable of easily and surely detecting disconnection, maintaining the function of a network even in the case of causing hit and easily recognizing and recovering a disconnected part. SOLUTION: In the conveyance system, the control boards for controlling a network in the convey are connected with forward and backward double loops 10 and 12 to form the network. Each of control boards is provided with a retriggerable timer 28, which is reset when a token is received, for detecting the disconnection when the token is not received longer than the transmitting interval of the token. In the case of disconnection, the disconnected loop is switched to a bus connection, the function is maintained and the disconnected part is displayed on a physical distribution computer 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport system provided with a network disconnection detecting device.

[0002]

2. Description of the Related Art In a transfer system using a tracked truck, an accumulation conveyor, and the like, a network is provided for controlling the transfer device, and each transfer device of the transfer system is controlled via the network. The network is a bus-like network that is easy to install.

[0003]

2. Description of the Related Art In order to prevent a system failure of a transport system, the inventors have considered making a network into a loop, but it has been difficult to detect a break in a loop network.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to detect a disconnection of a network for controlling a transport system and to easily find a location of the disconnection, thereby facilitating recovery. (Claims 1 to 3). An additional object of the present invention is to further enhance the durability of the transport system against disconnection and to easily detect which of the two loops in the forward direction and the reverse direction has been disconnected. . An additional object of the third aspect of the present invention is to enable an operator or the like to easily recognize a broken portion.

[0005]

According to the present invention, a network is arranged in a loop for controlling a transport device, connects a plurality of nodes, and a signal is transmitted to the network at an interval of a first predetermined time T1 or less. In the system as described above, if the node does not receive the signal for a second predetermined time T2 longer than the first predetermined time, a disconnection signal added with a signal specifying the node is transmitted to the network. A transport system provided with a network disconnection detecting device, wherein a disconnection detecting means for sending is provided (claim 1).

Preferably, the network comprises a loop for forward transmission (hereinafter referred to as “forward loop”) and a loop for reverse transmission (hereinafter referred to as “reverse loop”), and each of the nodes The disconnection detecting means is provided for each of the forward loop and the reverse loop (claim 2).

[0007] Preferably, a display terminal for displaying the state of the network is provided, and a disconnection location is obtained from a node specifying signal in the disconnection signal and displayed on the display terminal.

[0008]

According to the first aspect of the present invention, it is detected at each node whether or not a signal arrives at an interval within the second predetermined time T2. For this detection, for example, a timer or the like that is reset when a signal is received may be provided, and a timer may be used if a signal does not arrive within a predetermined time T2. If no signal is received during the second predetermined time T2, a disconnection signal is transmitted with a node ID signal or the like added. On the network management side, the disconnection point can be detected from the node identification signal (ID signal) attached to the disconnection signal. For these reasons, a disconnection can be easily detected even in a loop-like network, and a disconnection location can be easily specified. Further, since a loop-shaped network is used, even if a disconnection occurs at one location, the loop connection can be reconfigured into a bus connection and the function of the network can be maintained.

According to the second aspect of the present invention, since the network is constituted by a double loop of a forward loop and a reverse loop, if one of the loops is broken, the broken loop is reconfigured into a bus connection. And the other loop can be operated as before, so that the transport system does not go down. In addition, since the disconnection detecting means is connected at each node to each of the forward loop and the reverse loop, it is possible to easily confirm which loop is disconnected.

According to the third aspect of the present invention, the location of the disconnection is obtained from the node specifying signal in the disconnection signal, and the location of the disconnection is displayed on a display terminal such as a transport system. Therefore, the operator or the like can easily grasp the presence / absence and location of the disconnection.

[0011]

1 to 5 show an embodiment of a transport system provided with a control network. FIG. 1 and FIG. 2 show the configuration of the embodiment. Reference numeral 2 denotes a transport system as a whole, which here refers to a tracked truck system using a linear motor. Note that, instead of the tracked truck system, an automated guided vehicle system or a conveyor system such as an accumulation conveyor or a long-distance conveyor may be used, and the type of the transport system is arbitrary. Reference numeral 4 denotes a track of a tracked truck, which is installed, for example, along the ceiling of a clean room, and 6 denotes a track 4
In this case, it is assumed that the primary side of the linear motor is installed on the track 4 and the secondary conductor and the like are installed on the linear carriage 6. Instead of the linear trolley 6 on the ground, a linear trolley on the machine may be used.

Reference numeral 8 denotes a network for controlling the transport system 2, which includes a forward loop 10 and a reverse loop 12.
It is composed of heavy loops. 14 is a station control board, 16 is a linear motor control board, 18 is a central control unit, 20 is a manual control unit, these are nodes of the network 8, the central control unit 18 is a master unit, and the station control board 14 and Linear motor control board 1
6. The manual control unit 20 is a slave unit.

The station control board 14 is a board for controlling a station such as a stocker and a processing device provided along the track 4.
And a transfer device for transferring an article such as a semiconductor wafer or a liquid crystal substrate between the linear carriage 6 and the linear carriage 6.
A linear motor for starting is provided, and the transfer device and the linear motor are controlled by the station control board 14. The linear motor control board 16 is a board for controlling a linear motor provided between the station control boards 14.

The central control unit 18
A command is transmitted to the control boards 14 and 16 via the network 8, and a report from the control boards 14 and 16 is received and reported to the distribution computer 40 and the like shown in FIG.
The manual control unit 20 is a unit for manually controlling the insertion of the linear bogie 6 into the track 4 and the exit of the linear bogie 6 from the track 4, and the like, and a turntable 22 used for this purpose.

In the embodiment, the network 8 is a double loop. However, the loop may be a single loop, or a branch may be provided in the loop at the time of expansion. However, in this case, it is assumed that a node connected to the network 8 at the root of the branch is detected as to whether there is a disconnection at the branch. The medium of the loops 10 and 12 may be a normal conducting wire or an optical fiber.

FIG. 2 shows the control board 1 connected to the network 8.
6 are shown. 24 is a transmission / reception unit and 26 is a hub IC. 28 is a retriggerable timer, loop 1
0, 12 and a second predetermined time T2
If a token transmitted from the central control unit 18 or the like is not received at the following intervals, a message to that effect is output. Reference numeral 30 denotes a control unit of the central control unit 18, reference numeral 32 denotes a disconnection detecting unit thereof, reference numeral 34 denotes a control unit of the control board 16, and reference numeral 36 denotes a disconnection detecting unit thereof.
The station control board 14 and the manual control unit 20 are also provided with a control unit and a disconnection detection unit similar to those of the linear motor control board 16. If the disconnection detecting unit 36 does not receive the token during the second predetermined time T2, the loop in which the token has not been received has its own ID.
A signal is added and a disconnection signal is transmitted. Further, the disconnection detecting unit 32 of the central control unit 18 recognizes a disconnection position from the ID signal in the received disconnection signal. The disconnection detecting unit 32 of the central control unit 18 also detects a disconnection between itself and one of the upstream nodes.

FIG. 3 shows the mechanism of disconnection detection. A token is transmitted to each of the loops 10 and 12, for example, at a first time interval T1, and the retriggerable timer 28 is reset when the token is received, and is reset for a second predetermined time T2 longer than the token interval T1. If not reset in the meantime,
A disconnection signal is output to disconnection detection units 32 and 36. The disconnection detection unit 36 adds its own ID signal to the disconnection signal and transmits the signal to the output side of the disconnected loop. Therefore, unless a disconnection occurs simultaneously at two locations in one loop, the disconnection signal is ID
The signal is transmitted to the disconnection detecting unit 32 of the central control unit 18 together with the signal.

FIG. 4 shows the relationship between transmission and reception of a disconnection signal. 2
In one of the heavy loops, for example, it is assumed that a break has occurred between the board 2 and the board 3. Then, the token from the board 3 does not arrive at the board 2, and the board 2
Transmits a disconnection signal to the board 1 with its own ID when no token is received for the second predetermined time T2. The board 1 transfers this signal to the central control unit side, and the central control unit receives the disconnection signal from the board 2. In this case, the board 1 also detects the disconnection independently of the board 2, so that
The board 1 may also transmit its own disconnection detection signal to the central control unit, or may refrain from transmitting its own disconnection signal upon receiving the disconnection signal from the board 2. .

The central control unit 18 detects that the disconnection point is between the boards 2 and 3 because there is a disconnection signal from the board 2 and no disconnection signal from the board 3. In connection with this, in the loop where the disconnection has occurred, the boards 2 and 3 on both sides of the disconnection point
A loop is reconfigured into a bus connection having both ends as, for example, a token is sent from the board 2 to the board 3, and the board 3 returns the token to the board 2 when receiving the token, thereby forming a network as a bus connection. maintain. Also in this case, the loop on the side where the disconnection does not occur can be used as it is, and even if the disconnection occurs, the transport system does not go down.

FIG. 5 shows a network status display screen on the display terminal of the distribution computer, where solid lines in the figure indicate control points and broken lines in the figure indicate abnormal points.
It can be seen from the screen that a disconnection has occurred between the station No. 5 and the linear motor No. 5. Since the forward and reverse double loops are separately installed, the wire on the side where the disconnection has occurred may be replaced between the station No. 2 and the linear motor No. 5. In the embodiment, even if the token is not transmitted temporarily, it is displayed as a disconnection, but the state in which the token is not transmitted temporarily is displayed as a simple abnormality, and if an abnormality occurs, the loop is reconfigured to the bus. At the same time, the fact may be displayed on a display terminal such as a distribution computer or the like, and a disconnection may be displayed at a stage where the abnormality continues, so that maintenance and inspection may be requested. In addition, although the token is used for detecting the presence / absence of disconnection, the signal is not limited to the token as long as it is a signal transmitted periodically, for example, at intervals shorter than the second predetermined time T2.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layout of a transport system and a control network according to an embodiment.

FIG. 2 is a diagram showing connection of a central controller rule unit and each control board to a network in the embodiment.

FIG. 3 is a waveform diagram showing disconnection detection using a token flowing through a network, where (1) shows an input waveform to a retrigable timer and (2) shows an output waveform from a retrigable timer.

FIG. 4 is a transition diagram showing transmission of a disconnection signal from a control board of a network to a central control unit.

FIG. 5 is a diagram showing a network status display screen on the display terminal of the distribution computer.

[Explanation of symbols]

 2 Transport System 4 Track 6 Linear Truck 8 Network 10 Forward Loop 12 Reverse Loop 14 Station Control Board 16 Linear Motor Control Board 18 Central Control Unit 20 Manual Control Unit 22 Turntable 24 Transmitter / Receiver Unit 26 Hub IC 28 Retriggerable Timer 30 , 34 control unit 32, 36 disconnection detection unit 40 distribution computer

Claims (3)

[Claims] 1. A system in which a plurality of nodes are connected in a loop for controlling a transport device and a plurality of nodes are connected, and a signal is transmitted to the network at an interval of a first predetermined time T1 or less. In the above, when the signal is not received for a second predetermined time T2 longer than a first predetermined time, a disconnection signal added with a signal specifying the node is sent to each of the nodes. A transport system provided with a network disconnection detecting device, wherein a disconnection detecting means is provided. 2. The control network according to claim 1, wherein the control network comprises a forward transmission loop and a reverse transmission loop, and each of the nodes includes a forward transmission loop and a reverse transmission loop. The transport system provided with the network disconnection detecting device according to claim 1, wherein the disconnection detecting unit is provided for each of them. 3. A display terminal for displaying a state of a network, wherein a disconnection point is obtained from a node specifying signal in the disconnection signal and displayed on the display terminal. A transport system provided with the network disconnection detecting device according to item 1 or 2.