JPH0830970B2 - Series controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial controller in which a main controller and a plurality of nodes are connected in series, and a plurality of sensors and actuators are connected to each node. Measures against incomplete disconnection of the connector.

[0002]

2. Description of the Related Art When centrally managing presses, machine tools, construction machines, ships, aircraft, unmanned transport devices, unmanned warehouses, etc.,
A large number of sensors for detecting the state of each part of the device and a large number of actuators for controlling the state of each part of the device are required.
The number of sensors and actuators is, for example, more than 3000 when considering a press, and may be even larger in other devices.

Conventionally, as a centralized management system for centrally managing this type of device, a plurality of nodes are connected in series, one to a plurality of sensors and actuators are connected to each node, and these nodes are looped via a main controller. A configuration in which each node is controlled by a signal from the main controller is considered.

In the case where the nodes are connected in series in this way, the problem is how to secure the simultaneity of output 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, a time delay for this address processing becomes a problem, and the collection of the output of each sensor and the control of each actuator should be satisfied. Synchrony cannot be ensured.

Therefore, the inventors of the present invention abandoned the idea of assigning an address to each node while adopting a configuration in which nodes are connected in series, and each node is identified by the order of connection, thereby performing address processing. We have proposed a serial controller that eliminates the need for it, eliminates the time delay associated with address processing, and greatly simplifies the node configuration.

This device is constructed as shown in FIG. In this serial control device, the sensor groups 1-1, 1-
2, ... 1-N are arranged in each part of the machine and detect the state of each part of the machine. Actuator group 2-1 and 2
-2, ..., 2-N are arranged in each part of the machine and drive each part of the machine. These sensor group 1-N and actuator group 2-N are respectively connected to nodes 10-N (N = 1.
To N) and these nodes 10-1 to 10-10.
-N is connected in series in a loop including the main controller 100. The main controller 100 mainly controls data exchange with a plurality of connected nodes 10-1 to 10-N.

FIG. 7 shows a frame structure of a data signal used in the system when the number N of nodes is 5, and the data frame signal is sent from the main controller 100 to the nodes 10-1 and 10. -2 ...
After passing through 10-N, it is returned to the main controller 100. Note that FIG. 7A shows the main controller 10
The data frame signal immediately after being output from 0 is shown in nodes (b), (c), (d) and (e) of FIG.
The data frame signals output from 0-2, 10-3, and 10-4 are input to the main controller 100 by feeding back the signals output from the node 10-5 in FIG. Signal) respectively. The contents of each signal in the frame structure of FIG. 7 are as follows.

STI: Input data (sensor data) DI
Start code DI indicating the start position of the input data (sensor data) DIq; input data STO from the sensor connected to the qth node STO; second indicating the start position of the output data (actuator drive data) Start code DO; output data (actuator drive data) DOq; output data SP to the actuator connected to the q-th node SP; stop code DL indicating the end position of the data string DL; data indicating the length of the output data DO CRC; CRC code for CRC check ERR; code indicating presence / absence of error, error content and error position, in each node 10-1 to 10-N shown in FIG.
As shown in (b) to (f), the detection data DIq of the sensor 1 connected to the node is added between the start code STI and the start code STO, and the node is connected to the node after the start code STO. It operates so as to extract the output data DOq to the actuator 2.

Therefore, in this system, from the main controller 100 to the node 10-1 shown in FIG.
If a data frame signal including the actuator control data DO as shown in (a) is transmitted, this data frame signal becomes node 10-1 → node 10-2 → node 10
-3 → node 10-4 → 10-5 is sequentially propagated to allocate the actuator control data DO in the data frame signal to the corresponding node, and the detection data of the sensor group obtained at each node. Are taken into the same data frame signal. As a result, when the data frame signal is fed back to the main controller 100, as shown in FIG. 7 (f), all the actuator control data DO disappears and the detection data of the sensor group is included in the same frame signal. It will be.

Further, in this system, when a disconnection of a signal line or a connection connector between the nodes occurs, this disconnection is detected by the node immediately after the disconnection position. That is, the data frame signal is transmitted from the main controller at a predetermined sampling period Ts, and at each node, the data frame signal has a predetermined disconnection detection time Td (for example, Td = n × Ts,
When it is not received for n = 2 to 5) or more, this is detected as a disconnection. The node detecting the disconnection transmits a disconnection frame signal as shown in FIG.
This disconnection frame signal is a disconnection code B indicating the occurrence of disconnection.
RK and a disconnection number portion for identifying the disconnection occurrence position, and the node detecting the disconnection detects the disconnection number portion in the disconnection frame signal as, for example, number 1 (00000
(001, binary code) is initialized and transmitted. When each node receives this disconnection frame signal, the disconnection number part in the disconnection frame signal is incremented by 1 and sent to the next-stage node, and the main controller 100 disconnects the disconnection number part in the received disconnection frame signal. The position where the wire breakage occurs can be detected by determining. That is, since the disconnection number portion in the disconnection frame signal is sequentially incremented by 1 after the node that detected the disconnection, the disconnection occurrence position can be detected by back-calculating the disconnection number portion in the main controller.

FIG. 9 shows each node 10 which executes the above operation.
-1 to 10-N schematically shows the internal configuration,
The data frame signal from the preceding node or the main controller 100 is received by the receiving circuit 21. The STI detection circuit 22 detects the start code STI in the data frame signal shown in FIG. The BRK detection circuit 23 detects the disconnection code BRK in the disconnection frame signal shown in FIG. The SP detection circuit 22 detects the stop code SP in the data frame signal shown in FIG. Since the mask period generation unit 25 may overlap the ERR code, DL data, and CRC code parts in the data frame signal shown in FIG. 7 with the start code STI, these parts, that is, the SP code, ends and then the ERR is completed. The period tm until the code ends is the start code STI
Is a circuit for generating a mask signal for disabling the STI detection circuit 22 so as not to detect the signal. The counter 26 counts the clock signal CK from when the data frame signal of FIG. 7 or the disconnection frame signal of FIG. 8 is received until the data frame signal of FIG. 7 or the disconnection frame signal of FIG. 8 is received again. The time interval is measured, and the STI detection circuit 22 and BRK are measured.
The output of the detection circuit 23 is reset by the output of the OR gate 27. The above-described predetermined disconnection detection time Td (= n × Ts) is preset in the disconnection time setting circuit 28. The comparator circuit 29 sequentially compares the count value of the counter 26 and the disconnection set time Td, and outputs a disconnection detection signal DTBR when the count value ≧ Td. When the disconnection detection signal DTBR is input, the disconnection frame sending circuit 30 generates the disconnection frame signal shown in FIG. 8 in which the disconnection number portion is initially set to the number 1. Upon receiving the disconnection frame signal from the preceding node or the main controller 100, the +1 circuit 31 increments the disconnection number portion in this disconnection frame signal and outputs it to the subsequent device. The data input / output control unit 32 performs input / output control of sensor data and actuator data with respect to the data frame signal shown in FIG. 7, error detection processing, CRC check processing, etc., and sends the generated data frame signal to the subsequent device. To do. The data frame signal and the disconnection frame signal are appropriately selected by the selector 33 according to the situation, and output to the subsequent stage device via the transmission circuit 34. In the data input / output control unit 32, when the detection signal of the BRK detection circuit 23 is input (when a disconnection is detected at another node, etc.), or when the disconnection detection signal DTBR is output from the comparison circuit 29.
When is input (when a disconnection is detected at the node), the output data to the actuator group 2 is forcibly turned off for safety.

In such a system, when the main controller 100 receives a disconnection frame signal from a certain node, it determines the disconnection number portion and confirms the disconnection position, and then repeatedly transmits the disconnection frame signal from the main controller 100 again. By doing so, it is possible to reconfirm the disconnection occurrence position and improve safety by forcibly turning off the actuators not only in the nodes after the disconnection was detected but also in the nodes in front of the node where the disconnection was detected. ing. That is, as described above, each node is provided with the function of forcibly turning off the actuator connected to the node when receiving the disconnection frame signal, but only the disconnection frame signal transmitted from the node that has detected the disconnection. The only nodes that are forcibly turned off are the nodes after the node that detected the disconnection.
By sending the disconnection frame signal again from the main controller 100, the actuator connected to the node preceding the node where the disconnection was detected is forcibly turned off.

[0013]

However, in such a system, when an incomplete disconnection occurs such as a signal line between nodes is about to break, or a connector connecting the signal line and the node is about to come off, The incomplete disconnection may be detected by the node immediately after the incomplete disconnection position and the disconnection frame signal may be received by the main controller 100. However, the disconnection frame signal sent from the main controller 100 after this is the incomplete disconnection occurrence position. Therefore, the disconnection frame signal may not necessarily be interrupted, and the disconnection frame signal may pass through the incomplete disconnection occurrence position. In such a case, the disconnection number portion in the disconnection frame signal sent from the main controller 100 is incremented by 1 at all nodes and input to the main controller 100.
The disconnection position determined by the disconnection number part at this time (determined that no disconnection has occurred) and the disconnection position determined by the disconnection number part of the disconnection frame signal input from the first node (actual incomplete disconnection occurrence position Is not determined), the position where the disconnection occurs cannot be clearly specified in the main controller 100, and a great deal of labor and time are required to investigate the cause. Further, in the case of such an incomplete disconnection, it is preferable from the viewpoint of system safety that it can be detected before the complete disconnection.

FIG. 10 shows an example of a time chart when such an incomplete disconnection occurs. FIG. 10A shows a data frame signal sent by the main controller 100, and FIG. The received data frame signal at the node immediately after the incomplete disconnection position, the disconnection frame signal sent by the main controller 100 in FIG.
FIG. 7D shows the received disconnection frame signal at the node immediately after the incomplete disconnection position. In this case, the transmission period (sampling period) Ts of the data frame signal transmitted by the main controller and the transmission period (sampling period) Tb of the disconnection frame signal are set to be the same, and the disconnection detection set time Td at each node is 2Ts <Td <
It is assumed that the fixed setting is 3 Ts.

When the above-mentioned incomplete disconnection occurs,
Incorrect detection of special codes such as start code STI and stop code SP (which can be detected or cannot be detected) often occurs at the node immediately after the incomplete disconnection position. It is considered to be detected. That is, as described above, at each node, in order to prevent double detection of the STI code, the ERR code after the SP code in the data frame signal, the DL
ST when data and CRC code part is received
The detection of the I code is prohibited.
As shown in (b), an erroneous detection of a frame signal due to an SP code detection error or an STI code detection error indicated by an "X" mark occurs at the node immediately after the incomplete disconnection position due to the incomplete disconnection. , So this node has STI
Since the time from the detection of the code to the detection of the next STI code exceeds the disconnection detection set time Td, the disconnection is detected. Therefore, this node sends the disconnection frame signal as described above. This disconnection frame signal is received by the main controller 100, whereby the main controller 100 determines the disconnection position from the disconnection number portion in the received disconnection frame signal, and thereafter, for reconfirmation of the disconnection position and for all nodes. Figure 1 shows a broken frame signal to turn off the actuator.
As shown in 0 (c), in a cycle Tb (in this case, Tb = T
s) Send periodically. This main controller 100
It is preferable that the disconnection frame signal sent from the device is blocked at the incomplete disconnection position and not received by the node immediately after the incomplete disconnection position. However, as shown in FIG. There are cases where it is received, but it also appears. Therefore, when the disconnection frame signal sent by the main controller 100 passes through this incomplete disconnection position, the disconnection frame signal is incremented by 1 at each node and input again to the main controller 100, and the disconnection occurrence position is detected. It cannot be specified.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a serial control device capable of efficiently detecting an incomplete disconnection between nodes before it becomes a complete disconnection.

[0017]

According to the first aspect of the present invention, nodes connected with one or more sensors and one or more actuators are connected in series, and the plurality of nodes are connected in a closed loop including a main controller. , The main controller sends a data frame signal including output data to the actuator at a predetermined sending cycle, and each node adds data from a sensor connected to the node to the data frame signal and The output data to the actuator connected to is operated so as to be extracted from the data frame signal, and each node detects the occurrence of disconnection when the reception interval of the data frame signal exceeds a predetermined disconnection set time, and disconnection occurs. When detected, the disconnection code indicating the occurrence of disconnection and the initial setting of the disconnection occurrence position data will be The node to which the disconnection frame signal is input, the node to which the disconnection frame signal is input, increments the disconnection occurrence position data in the disconnection frame signal by +1 and forcibly turns off the output data to the actuator of the node, and The controller is a serial control device that detects the disconnection position based on the disconnection occurrence position data in the input disconnection frame signal, and the forced off data frame in which all output data to the actuator of the data frame signal is turned off. The main controller includes a forced off-data frame signal forming means for forming a signal and a cycle setting means for setting the transmission cycle of the forced off-data frame signal to be longer than the transmission cycle of the data frame signal and transmitting the main controller. When a disconnection is detected,
The forced off data frame signal whose transmission cycle is set longer than the transmission cycle of the data frame signal is transmitted.

According to the second aspect of the present invention, the nodes to which one to a plurality of sensors and one to a plurality of actuators are connected are connected in series, and the plurality of nodes are connected in a closed loop including a main controller. An actuator which transmits a data frame signal including output data to the actuator at a predetermined transmission cycle, each node adds data from a sensor connected to the node to the data frame signal, and is connected to the node The output data to the data frame signal is operated to be extracted from the data frame signal, and each node detects the occurrence of disconnection when the reception interval of the data frame signal exceeds a predetermined disconnection set time and detects the occurrence of disconnection. The disconnection code that includes the disconnection code shown and the default disconnection occurrence position data. The node to which the disconnection frame signal is input adds one to the disconnection occurrence position data in the disconnection frame signal and forcibly turns off the output data to the actuator of the node and the main controller inputs The disconnection position is detected based on the disconnection occurrence position data in the generated disconnection frame signal, and then the disconnection occurrence position is reconfirmed by sending the disconnection frame signal at a predetermined sending cycle, and the actuators of all nodes are checked. In the serial controller forcibly turned off, the main controller is provided with a cycle setting means for setting the transmission cycle of the disconnection frame signal to be longer than the normal transmission cycle and transmitting it, and detects an incomplete disconnection. At this time, the disconnection frame signal whose transmission cycle is set longer than the normal cycle is transmitted.

[0019]

According to the first aspect of the invention, when it is determined that the incomplete disconnection has occurred, the disconnection frame signal is not transmitted, but the output data to the actuator of the data frame signal is all turned off. Send a data frame signal. Then, the transmission cycle of the forced off data frame signal is set longer than the transmission cycle of the data frame signal and transmitted. That is, since the forced off data frame signal in which all the output data of the normal data frame signal is turned off has more special codes (start code stop code) than the disconnection frame signal, the forced off data frame signal is generated at each node. The detection probability of the special code should be lower than that of the disconnection frame signal. Further, a longer transmission cycle of the forced off data frame signal means that the disconnection detection setting time in each node is fixed, and thus the probability of disconnection detection in each node is increased.
In short, according to the first aspect of the present invention, when the incomplete disconnection occurs, the probability that the disconnection is detected in the corresponding node is increased so that the forced off data frame signal sent by the main controller is immediately after the incomplete disconnection position. This prevents the situation where the main controller passes through the node and is received again by the main controller.

Further, in the second aspect of the invention, when it is determined that the incomplete disconnection has occurred, the disconnection frame signal is set to be transmitted longer than the normal transmission cycle. That is, by setting the transmission cycle of the disconnection frame signal longer than the normal transmission cycle, the probability that a disconnection is detected at the node immediately after the incomplete disconnection position is increased, and this causes the disconnection frame signal to be generated from this node. To do so.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention, and schematically shows a main part configuration in the main controller 100.

The normal data frame transmission circuit 40 is shown in FIG.
The data frame signal shown in (1) is formed and transmitted.

The forced off data frame sending circuit 45 forms a forced off data frame signal as shown in FIG.
Output this. The forced off data frame signal shown in FIG. 3 is obtained by setting all the output data DO to the actuators 2-1 to 2-N in the normal data frame signal shown in FIG. 7 to "0". The length m of the output data DO in the forced off data frame signal is set to a value larger than the expected total number of actuators when the total number of actuators connected to all nodes is unknown. The sampling time setting circuit 50 sets the transmission cycle Tk (sampling cycle) of the forced off data frame signal, and when the switch 60 is turned on, the sampling cycle Tk is set as the transmission cycle of the data frame signal shown in FIG. (Ts in FIG. 10) is output and the switch 60 outputs
When is not input, the normal data frame signal transmission cycle Ts is output.

The selector 55 selectively switches between the output frame of the normal data frame transmission circuit 40 and the output frame of the forced off data frame transmission circuit 50 according to the closed state of the switch 60, and transmits the selected frame signal to the node.

The operation of the configuration of FIG. 1 will be described with reference to the flowchart of FIG.

When the operator determines that the incomplete disconnection has occurred due to the occurrence of the above-described event (step 200), the switch 60 is operated to cause the sampling time setting circuit 50 to transmit the normal data frame signal transmission cycle. (Ts of FIG. 10) A transmission cycle Tk longer than the forced off data frame signal is set and the selector 55
Is switched to the forced off data frame sending circuit 45 side. As a result, the main controller 100 sequentially transmits the forced off data frame signal whose transmission cycle Tk is longer than the transmission cycle of the normal data frame signal to the nodes (step 210).

This forced off data frame signal propagates through each node and reaches an incomplete disconnection point after turning off the actuator connected to each node. At this incomplete disconnection point, it is actually unknown whether the forced off-data frame signal passes through as if no disconnection occurs or is interrupted here. However, in this case, a forced-off data frame signal including the same special code (STI code, SP code) as the normal data frame signal is used instead of the conventional disconnection frame signal. Ie 2 in the frame
A forced off-data frame signal having one special code (STI code, SP code) should have a lower probability of detecting a special code than a disconnection frame signal in which only the disconnection code BRK has a special code. Therefore, the probability of occurrence of the phenomenon as shown in FIG. 10B at the node immediately after the incomplete disconnection point increases, and the possibility that disconnection will be detected at this node also increases. Further, since the transmission cycle of the forced off data frame signal is set longer than the transmission cycle of the normal data frame signal, the forced off data frame signal is transmitted to the node before the disconnection detection setting time set in the node elapses. The number of inputs is reduced, and as a result, the possibility that a disconnection is detected at the node immediately after the incomplete disconnection point is further increased.

That is, in FIG. 1, in the case of incomplete disconnection, the above-mentioned forced off data frame signal is transmitted and the transmission cycle thereof is lengthened to intentionally detect the disconnection at the node immediately after the incomplete disconnection point. In this case, an incomplete disconnection is detected as an occurrence of disconnection at this node by creating a susceptibility situation.

At the node immediately after the incomplete disconnection location where the occurrence of disconnection is detected, a disconnection frame signal in which the disconnection number portion shown in FIG. 8 is initialized is transmitted. The disconnection frame signal is input to the main controller 100 after the disconnection number portion is sequentially incremented by 1 in the subsequent node (step 220). In the main controller 100,
The incomplete disconnection position is determined by back-calculating the disconnection number portion of the input disconnection frame signal (step 230).
The incomplete disconnection position determined this time coincides with the incomplete disconnection position determined by the disconnection frame signal output from the node immediately after the first incomplete disconnection position. It will not be impossible to specify.

By the way, regarding the transmission cycle Tk of the forced off data frame signal, when the disconnection detection setting time Td at each node is set as 2Ts <Td <3Ts as shown in FIG. 10, For example, the transmission cycle Tk of the forced off data frame signal is Td <3Tk, Tk
<Td is set.

FIG. 4 shows another embodiment of the present invention, which is a normal data frame signal transmission circuit 40 and a selector 5.
5 and the switch 60 have the same configuration as that shown in FIG.

The disconnection frame signal transmitting circuit 65 is for transmitting the disconnection frame signal shown in FIG. 8, and the disconnection number portion of this disconnection frame signal is initialized to an appropriate value such as number 1. . The sampling time setting circuit 70 sets the transmission cycle Tb (sampling cycle) of the disconnection frame signal, and the transmission cycle Tb of the disconnection frame signal in the case of detecting an incomplete disconnection detects a conventional complete disconnection. The transmission cycle is set to be longer than the transmission cycle of the disconnection frame signal. Specifically, the transmission cycle Tb of the disconnection frame signal is extended to detect the disconnection code even once even at the node immediately after the incomplete disconnection, and if the disconnection code fails, the occurrence of the disconnection is detected at that node. For example, assuming that the disconnection detection setting time Td in each node is 30 msec, Tb is, for example, 20.
msec.

The operation of the configuration of FIG. 4 will be described with reference to the flowchart of FIG.

When the operator determines that the incomplete disconnection has occurred due to the occurrence of the above-mentioned event (step 300), the operator operates the switch 60. As a result, the sampling time setting circuit 70 sets the transmission cycle Tb of the disconnection frame signal longer than the transmission cycle of the disconnection frame signal when the normal complete disconnection is detected, and the selector 55 shifts to the disconnection frame signal transmission circuit 65 side. Can be switched. As a result, the main controller 100 sequentially transmits the disconnection frame signals whose transmission cycle Tb is longer than usual to the nodes (step 310).

This disconnection frame signal propagates through each node and reaches an incomplete disconnection point after turning off the actuator connected to each node. At this incomplete disconnection point, it is actually unclear whether this disconnection frame signal passes through as if no disconnection occurred or is interrupted here. However, in this case, since the disconnection frame signal is transmitted in a cycle longer than the normal cycle, the number of times the disconnection frame signal is input to the node before the disconnection detection setting time Td set in the node elapses. Is reduced, and as a result, there is a high possibility that the disconnection is detected at the node immediately after the incomplete disconnection point. Then, as described above, when the disconnection frame signal transmission cycle Tb is set such that the disconnection code is detected even once even if the node fails to detect the disconnection occurrence at that node, the disconnection occurrence is detected. The probability of whether or not to increase to 1/2.

That is, also in FIG. 4, in the case of incomplete disconnection, the transmission cycle of the disconnection frame signal is lengthened to intentionally create a situation in which the disconnection is likely to be detected at the node immediately after the incomplete disconnection point. At this node, an incomplete disconnection is detected as a disconnection occurrence.

At the node immediately after the incomplete disconnection location where the occurrence of disconnection is detected, a disconnection frame signal in which the disconnection number portion shown in FIG. 8 is initialized is transmitted. This disconnection frame signal is added to the main controller 100 after the disconnection number portion is sequentially incremented by 1 in the subsequent node as described above.
(Step 320). The main controller 100 determines the incomplete disconnection position by back-calculating the disconnection number portion of the input disconnection frame signal (step 330).

In this way, even in the case of an incomplete disconnection, it is possible to reliably detect the position where the incomplete disconnection occurs before it becomes a complete disconnection.

[0040]

As described above, according to the present invention,
When an incomplete disconnection such as disconnection of the signal line between nodes or disconnection of the connector occurs, the transmission cycle of the compulsory off data frame signal or disconnection frame signal is set to be extended so that the incomplete disconnection occurs. The probability that an incomplete disconnection will be detected as a disconnection at the node immediately after the location becomes high, and thus the position where the incomplete disconnection occurs can be efficiently detected.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the embodiment.

FIG. 3 is a diagram showing an example of a forced off-frame signal.

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is a flowchart illustrating the operation of the embodiment shown in FIG.

FIG. 6 is a block diagram showing the overall configuration of a serial control device to which the present invention is applied.

FIG. 7 is a diagram showing a manner of propagation of a data frame signal.

FIG. 8 is a diagram showing a disconnection frame signal.

FIG. 9 is a diagram showing a schematic internal configuration of a node.

FIG. 10 is a time chart showing a situation of occurrence of incomplete disconnection.

[Explanation of symbols]

 1 ... Sensor group 2 ... Actuator group 10 ... Node 40 ... Normal data frame transmission circuit 45 ... Forced off data frame transmission circuit 50, 70 ... Sampling time setting circuit 65 ... Disconnection frame signal transmission circuit 100 ... Main controller

Claims (2)

[Claims] 1. A node in which one or a plurality of sensors and one or a plurality of actuators are connected is connected in series, the plurality of nodes are connected in a closed loop including a main controller, and the main controller is connected to the actuator. A data frame signal including output data is transmitted in a predetermined transmission cycle, each node adds data from a sensor connected to the node to the data frame signal, and output data to an actuator connected to the node. With the disconnection code indicating that disconnection occurs when the reception interval of the data frame signal exceeds a predetermined disconnection set time, and each node detects disconnection. Outputs the disconnection frame signal including the initial setting of the disconnection occurrence position data, The node to which the disconnection frame signal is input adds +1 to the disconnection occurrence position data in the disconnection frame signal.
A serial controller for adding and forcibly turning off the output data to the actuator of the node, and detecting the disconnection position based on the disconnection occurrence position data in the input disconnection frame signal while the main controller is forcibly turned off. In the main controller, a forced off data frame signal forming means for forming a forced off data frame signal in which all output data of the data frame signal to the actuator is turned off, and a transmission cycle of the forced off data frame signal are And a period setting means for setting and transmitting the data frame signal for a longer period than the transmission period of the data frame signal, and when the incomplete disconnection is detected, the transmission period is set longer than the transmission period of the data frame signal. Serial control device characterized by transmitting data frame signal . 2. A node in which one or a plurality of sensors and one or a plurality of actuators are connected is connected in series, and the plurality of nodes are connected in a closed loop including a main controller, and the main controller is connected to the actuator. A data frame signal including output data is transmitted in a predetermined transmission cycle, each node adds data from a sensor connected to the node to the data frame signal, and output data to an actuator connected to the node. With the disconnection code indicating that disconnection occurs when the reception interval of the data frame signal exceeds a predetermined disconnection set time, and each node detects disconnection. Outputs the disconnection frame signal including the initial setting of the disconnection occurrence position data, The node to which the disconnection frame signal is input adds +1 to the disconnection occurrence position data in the disconnection frame signal.
In addition to forcibly turning off the output data to the actuator of the node concerned, the main controller detects the disconnection position based on the disconnection occurrence position data in the input disconnection frame signal, and thereafter the disconnection frame signal In the serial controller that reconfirms the disconnection occurrence position by forcibly turning off the actuators of all the nodes by sending the disconnection frame signal to the main controller. Equipped with a cycle setting means to set and send longer than the normal sending cycle,
A serial controller characterized in that when an incomplete disconnection is detected, a disconnection frame signal whose transmission cycle is set longer than the normal cycle is transmitted.