JPH0817399B2 - Series controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applied to a centralized management system for various machines such as presses, machine tools, construction machines, and ship aircraft, and an unmanned conveyor system, centralized management system for unmanned warehouses, and the like. And a preferred serial controller.

[Conventional technology]

When centrally managing presses, machine tools, construction machines, ships, aircraft, unmanned conveyors, unmanned warehouses, etc., many sensors that detect the status of each part of the equipment and many actuators that control the status of each part of the equipment are required. . The number of sensors and actuators is 30 when considering a press, for example.
There may be more than 00, and even more in other devices.

Conventionally, a centralized management system that centrally manages this type of device connects a large number of sensors and actuators described above to a main controller, collects a large number of sensor outputs by the main controller, and outputs a large number of actuators by signals from the main controller. Is configured to control.

In such a conventional centralized management system, if the number of sensors and the number of actuators become enormous, the number of wirings connecting the main controller and the sensors and actuators also becomes enormous, and the wiring length becomes very long. Also, the configuration of the input / output unit of the main controller becomes very complicated.

Therefore, a plurality of nodes are connected in series, one to a plurality of sensors and actuators are connected to each node, these nodes are annularly connected via a main controller, and each node is controlled by a signal from this main controller. Such a configuration is considered. In such a configuration, the main controller basically needs only the signal input line and the output line, and each node has a sensor,
Since it can be placed near the actuator, the wiring length can be greatly reduced.

However, in the case where the above-mentioned nodes are connected in series, the problem is how to secure the simultaneity of output collection of each sensor and the simultaneity of control of each actuator. For example, considering a configuration in which an address is assigned to each node and each node is controlled based on this address, the time delay for this address processing becomes a problem, and the output of each sensor and the control of each actuator are satisfied. It is not possible to ensure idempotency.

Therefore, the inventors have abandoned the idea of assigning an address to each node while adopting a configuration in which each node is connected in series, and identify each node by the order of its connection, thereby making address processing unnecessary. In addition, we have proposed a serial controller that eliminates the time delay associated with address processing, and that can greatly simplify the node configuration.

According to this device, each node sequentially adds the output signal of the sensor in its own node to the signal from the upstream node based on a predetermined rule, and the signal from the upstream node to its own node. Are sequentially extracted based on a predetermined rule, and output to the actuator in the own node. In this case, no address is required for each node, and since address processing is not required, the time delay in each node is very small only for timing adjustment, and the node configuration is also very simple. .

By the way, in the case of the above configuration, if a disconnection accident occurs between each node and the ring-shaped transmission line of the own node, the signal from the upstream node is not received at all for a certain period of time, The actuator is maintained in the state immediately after the wire break accident. However, since the transmission path with the main control device is normally maintained at the node upstream of the disconnection accident site, the operation according to the signal from the main control device is continued. Therefore, in the entire system, some nodes are operated by the signal from the main controller and some are stopped immediately before the disconnection accident, and the operation realized by the combination of the operations of all nodes. Has a problem of causing an accident such as damage to the device itself or the controlled object.

[Problems to be Solved by the Invention]

As described above, in the conventional serial control device, when a disconnection accident occurs between each node and the transmission line, the node that continues to operate by the signal from the main control device and the node immediately before the disconnection accident will stop. Since there are mixed nodes, the system as a whole malfunctions, and there is a problem that an accident such as damage to the device itself or a control target object occurs.

An object of the present invention is to provide a series control device capable of preventing damage to the device itself or a control target even if a disconnection accident occurs.

[Means for solving the problem]

In the present invention, the main control unit and a plurality of nodes are connected to one annular one-way transmission line, and each node extracts the information for its own node from the time-series information transmitted from the main control unit, Controls a terminal device connected to its own node, inserts output information of the terminal device into a time slot corresponding to its own node, sends out to a transmission line, and sends to a main control device via another downstream node. In the serial control device for transmitting, each node outputs a disconnection code and a disconnection position code by the disconnection detection means for detecting the occurrence of a disconnection accident between itself and the transmission line, and the disconnection detection signal of this disconnection detection means. When the disconnection detection signal is generated from the disconnection accident information transmitting means for generating the disconnection accident information including the disconnection accident information and transmitting the disconnection accident information to the downstream node or the main controller, Or a control means for actuating the terminal device connected to the own node to the safe side when the disconnection accident information transmitted from either the upstream node or the main control device is received, and the upstream node and the main control device. And a disconnection position code updating means for transmitting the disconnection position code in the disconnection accident information to the downstream node or the main controller when the disconnection accident information transmitted from any one of the above is received. Is a disconnection detecting means for detecting the occurrence of a disconnection accident in the transmission line between the main control device and the adjacent node on the downstream side, and a disconnection in the received disconnection accident information when the disconnection accident information is received. When the disconnection detection signal is input from the disconnection detection means in the main control unit or when the disconnection accident information is received, the disconnection coordinator determines whether the disconnection is in progress or has been recovered based on the position code. Disconnection accident information including a code and a disconnection position code, and disconnection accident information is transmitted to the upstream node of the disconnection accident location until the judgment means determines that the disconnection accident has been completed. And means for transmitting accident information.

[Action]

When each node detects a disconnection accident between its own node and the transmission line, each node sequentially transmits the disconnection accident information to the downstream node and notifies the main controller. The main controller transmits the disconnection accident information to the node upstream of the disconnection accident.

The node that detects the disconnection accident forces the terminal device of its own node to operate safely. Also, the node receiving the disconnection accident information forcibly operates the terminal device of its own node to the safe side.

As a result, the terminal devices (eg, actuators) of all the nodes operate safely, and the entire system is stopped. Further, the main control device determines whether the disconnection is being performed or the disconnection has been completed based on the disconnection position code in the disconnection accident information.
As a result, damage to the device itself or the controlled object due to a malfunction of the system is prevented in advance, and it is accurately determined whether the disconnection is in progress or the disconnection has been completed.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a main controller 2 connected to an annular transmission line 1 and n
Node 3-1 to 3-n, and each node 3-1
~ 3-n has multiple sensors S1 ~ Si and actuator A1 ~
Ak is connected.

As shown in FIG. 2 (a), the main controller 2 starts with a start code ST, then control information DATA for each node, then a stop code SP indicating the end of the information part,
Finally, communication information in which an error check code ERC such as a parity check code or CRC code is arranged is sent to the transmission line 1. This communication information is sent to each node 3-1 to 3-1 via the transmission line 1.
3-n is transmitted in series.

Upon receiving the communication information from the transmission line 1, each of the nodes 3-1 to 3-n extracts the control information of the time slot corresponding to the connection number of its own node and controls the actuators A1 to Ak by this control information. Also, the output signals of the sensors S1 to Si are inserted into the time slot corresponding to the connection number of the own node and transmitted to the node on the downstream side.

Therefore, the control information transmitted from the main controller 2
DATA is replaced with the sensor output signal of each node when being output from the node 3-n on the most downstream side. The main controller 2 grasps the state of each node 3-1 to 3-n by this sensor output signal, and proceeds to the next control step.

Here, each of the nodes 3-1 to 3-n notifies the main controller 2 of the disconnection accident information via the downstream node when a disconnection accident occurs between the node itself and the transmission line 1.

For example, when a disconnection accident occurs on the transmission line between the nodes 3-2 and 3-1 in FIG. 1, the node 3-2 becomes the transmission source of the disconnection accident information, and as shown in FIG. 2 (b). To the main controller 2 through the disconnection accident information including the disconnection code BRK and the disconnection position code No. (0).

The disconnection accident information is received by the nodes 3-3 to 3-n on the downstream side. When these nodes receive the disconnection accident information, the actuators A1 to Ak in the own node are forcibly operated to the safe side. In addition, the disconnection position code No. (0) is updated by "1" and transmitted to the downstream node. As a result, the disconnection accident information whose disconnection position code is "No. (n-2)" is transmitted from the most downstream node 3-n as shown in FIG. 2 (c), and is input to the main controller 2. To be done.

For the main controller 2, the disconnection position code is "No.
-2) ", it was confirmed that there was a disconnection accident immediately before the second node 3-2 from the upstream side, and the actuator for the upstream node 3-1.
Information for safely operating A1 to Ak, that is, the second
Information of DATA = 0 is transmitted as shown in FIG. As a result, the node 3-1 operates the actuators A1 to Ak connected to its own node to the safe side similarly to the nodes 3-3 to 3-n. On the other hand, the node 3-2 that is the transmission source of the disconnection accident information is also the actuator A1 connected to its own node.
~ Activate Ak to the safe side.

As a result, the system stops with the actuators A1 to Ak of all the nodes operating safely.

Here, the occurrence of the disconnection accident can be easily detected by the fact that the communication information has not been transmitted for a predetermined time or more from the upstream node (the main controller for the most upstream node). However, in the example of FIG. 1, when a disconnection accident occurs just before the node 3-2, the nodes 3-3 to 3-n are transiently detected as the disconnection accident, but finally, Only the node 3-2 is fixed as the transmission source of the disconnection accident information, and the other nodes 3-3 to 3-n are released from the disconnection detection state.

FIG. 3 is a configuration diagram showing an embodiment of the internal configuration of the nodes 3-1 to 3-n, and the communication information from the upstream node is received by the input circuit 30. The input circuit 30 has a circuit configuration for demodulating the communication information into an NRZ code when the communication information is modulated and transmitted. The communication information to be demodulated is the data processing circuit 31,
Disconnection detection circuit 32, disconnection code detection circuit 33, error determination circuit
Entered in 34.

The data processing circuit 31 extracts only the control information DATA for its own node from the control information DATA for all the nodes included in the demodulated communication information, holds it in the latch circuit 35, and then outputs the output signals of the sensors S1 to Sn. It is inserted into the time slot corresponding to its own node, modulated by the output circuit 36, and transmitted to the downstream node. The latch circuit 35 sends the held control information to the actuator drive signal generation circuit 39 via the gates 37 and 38 to drive the actuators A1 to Ak.

On the other hand, the error judgment circuit 34 judges the presence or absence of an error in the reception control information DATA by the error check code, opens the gate 37 if an error is found, and inputs the control information from the latch circuit 35 to the actuator drive signal generation circuit 39. Prohibit

Further, the disconnection detection circuit 32 detects that a disconnection accident has occurred on the upstream side of the own node when the communication information from the upstream node is not received for a predetermined time or more determined by a timer (not shown). The data processing circuit 31 to the second
The disconnection accident information having the frame structure shown in FIG. 7B is generated and transmitted to the downstream node via the output circuit 36.
Further, the disconnection detection signal is input to the AND gate 38 via the OR gate 40 as a prohibition input, and if the AND gate 38 is opened, the AND gate 38 is closed as shown in the time chart of FIG. ~ Stop driving Ak. The actuators A1 to Ak operate on the safe side and stop when the drive signal is stopped.

On the other hand, when the disconnection accident information having the frame structure as shown in FIG. 2 (b) is received, the disconnection code detection circuit 32 detects the disconnection code BRK in the disconnection accident information, and the upstream side of the own node Recognizing that a disconnection accident has occurred, a signal equivalent to the disconnection detection signal of the disconnection detection circuit 32 is input to the OR gate 40 to stop the driving of the actuators A1 to Ak.

FIG. 5 is a configuration diagram showing an embodiment of the internal configuration of the main controller 2, and the input circuit 50 receives communication information from the node 3-n on the most downstream side. The input circuit 50 has a circuit configuration for demodulating the communication information into an NRZ code when the communication information is modulated and transmitted. The demodulated communication information is input to the frame processing circuit 51, the disconnection detection circuit 52, and the disconnection code detection circuit 53.

Based on the sensor output signals of all the nodes included in the demodulated communication information of the frame processing circuit 51, the states of all the nodes are grasped, and the control information DATA of all the nodes for advancing to the next step is determined. The frame generation circuit 54 generates communication information having a frame structure as shown in FIG. 2 (a), inputs it to the output circuit 56 via the switch 55, and the output circuit 56 converts it into, for example, a CMI code. Upstream node 3-1
Send it to.

The disconnection detection circuit 52 is similar to the disconnection detection circuit 32 of the nodes 3-1 to 3-n in the case where the communication information is not input from the most downstream node 3-n for a certain time or longer.
It is detected that a disconnection accident does not occur with n, and the stop frame generation circuit 57 is caused to generate the communication information of the frame structure as shown in FIG. 2D, and the disconnection detection signal is sent to the OR gate 58. Input to switch 55 through switch 55
Is switched to the position of "2" and is transmitted from the output circuit 56.
This is the same when the disconnection code detection circuit 53 detects the communication information including the disconnection code BRK from the node 3-n.

FIG. 6 is a time chart showing the operation of each unit when a disconnection is detected.

It should be noted that instead of transmitting the communication information of FIG. 2 (d) in which the control information DATA for all nodes is “0”, the disconnection accident information of the same frame configuration as in FIG. 2 (b) is generated and transmitted, The actuator of the node upstream of the disconnection accident site may be configured to operate safely.

FIG. 7 is a block diagram showing another embodiment of the main controller 2 for transmitting the disconnection accident information similar to that shown in FIG. 2B, and the disconnection is made in place of the stop frame generation circuit 57 of FIG. A frame generation circuit 59 is provided. Further, a disconnection code number determination circuit 60 for determining that the disconnection position code is "n-1" or less is provided.

Here, when a disconnection accident occurs between the nodes 3-1 and 3-2, the communication information of the disconnection position code = n-2 is main from the node 3-n on the most upstream side as shown in FIG. It is input to the controller 2. Therefore, the main controller 2
In order to operate the actuators A1 to Ak of the node 3-1 to the safe side, the disconnection accident code information of the disconnection position code = 0 is generated by the disconnection frame generation circuit 59 and transmitted, as shown in FIG.

As a result, the actuators A1 to Ak of the node 3-1 operate on the safe side and stop.

When the disconnection accident between the nodes 3-1 and 3-2 is recovered in this state, as shown in FIG.
The disconnection accident information transmitted by the device returns via the nodes 3-1 to 3-n. At this time, the disconnection position code is updated to "n". When the disconnection state continues, the disconnection position code of the disconnection accident information input to the main controller 2 is always n-1 or less. Disconnection code number judgment circuit 60
Judges that the disconnection position code is "n-1" or less, and when it is "n-1" or less, it is confirmed that the disconnection accident continues in any of the transmission paths, and the disconnection code detection circuit 53
And an OR gate 58 provided between the OR gate 58 and the OR gate 58, the switch 55 is switched to the position of "2", and the disconnection accident information generated by the disconnection frame generation circuit 59 is output to the output circuit 56.
Signal from.

However, if the disconnection position code is “n”,
Since the disconnection accident information that I sent was returned, I recognized that the disconnection accident was restored, and AND Gate
Close 61 to stop the transmission of disconnection accident information.

FIG. 10 is a time chart showing the operation of each part shown in FIG.

In the above-described embodiment, the disconnection disconnects the drive signal to the actuators A1 to Ak, but it goes without saying that the actuators on the safe side are in the continuous drive state.
This can be done by replacing the gate 38 with an OR gate.

〔The invention's effect〕

As described above, in the present invention, when a disconnection accident occurs in the ring transmission line, the disconnection accident information is transmitted from the node on the downstream side of the disconnection accident site, and the terminal devices of all the nodes are forced to the safety side. Since it is operated in the above manner, it is possible to prevent the loss of the device itself or the controlled object due to the malfunction of the system. Further, in the present invention, since the control device is provided with the determination means for determining whether the wire is being disconnected or the wire has been restored based on the wire position code in the wire accident information, it is possible to accurately determine whether the wire is being disconnected or the wire has been restored. To be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a frame configuration diagram of normal communication information and communication information at the time of disconnection,
FIG. 3 is a configuration diagram showing an embodiment of the internal configuration of the node, FIG.
FIG. 5 is a time chart showing the operation of each part of the node, FIG. 5 is a block diagram showing an example of the internal configuration of the main controller, FIG. 6 is a time chart showing the operation of each part of the main controller 3, and FIG. FIG. 8 is a block diagram showing another embodiment of the main controller, FIG. 8 and FIG. 9 are diagrams showing changes in the disconnection accident information transmitted at the time of disconnection and restoration at the main controller of FIG. 7, and FIG. 6 is a time chart showing the operation of each part of the main controller in the figure. 1 ... Transmission line, 2 ... Main controller, 3-1 to 3
-N ... node, S1-Si ... sensor, A1-Ak ... actuator, 32,55 ... disconnection detection circuit, 33,53 ... disconnection code detection circuit, 38 ... gate, 57 ... stop frame generation Circuit, 59 ... Broken frame generation circuit.

Claims (2)

[Claims] 1. A main control device and a plurality of nodes are connected to a ring-shaped one-way transmission line, and each node extracts information for its own node from the time-series information transmitted from the main control device. , While controlling the terminal device connected to its own node,
In a serial control device that inserts the output information of the terminal device into a time slot corresponding to its own node, sends it to the transmission line, and sends it to the main control device via another node on the downstream side, each node is Disconnection detection means for detecting the occurrence of a disconnection accident between the transmission line and the transmission line, and disconnection detection information including the disconnection code and disconnection position code is generated by the disconnection detection signal of this disconnection detection means. When the disconnection accident information transmitting means for transmitting to the downstream node or the main control device and the disconnection detection signal from the disconnection detection means in the own node are input, or the disconnection detection signal is transmitted from either the upstream node or the main control device. Disconnection accident information received from any of the upstream side node and the main control device, and the control means to operate the terminal device connected to the own node to the safety side when it receives the information. When the accident information is received, the disconnection position code in the disconnection accident information is incremented by 1 and transmitted to the downstream node or the main control device. Disconnection detecting means for detecting the occurrence of a disconnection accident in the transmission line between the adjacent node on the side of the line, and disconnection based on the disconnection position code in the received disconnection accident information when the disconnection accident information is received. A disconnection code including a disconnection code and a disconnection position code when a disconnection detection signal is input from the disconnection detection means in the main control unit or when disconnection detection information is received. Disconnection accident information transmitting means for generating information and transmitting the disconnection accident information to a node on the upstream side of the disconnection accident point until the determination means determines that the disconnection accident has been completed. , Serial control apparatus characterized by comprising a. 2. The serial control device according to claim 1, wherein, when the main controller receives the disconnection accident information, it has disconnection position determination means for determining a disconnection position based on a disconnection position code in the disconnection accident information. .