JPH0318148A - Data transmission network system - Google Patents

Abstract

PURPOSE:To keep the function of a network normally by excluding a fault caused ion one optional controller in the network from a transmission line when the fault takes place in the controller. CONSTITUTION:When the abnormality takes place in any network controller among network controllers 11-1n building up the network, the abnormality detection means 20 of the controller detects the abnormality. A control means composed of a CPU 11 and a ROM 13 switches a switching means 22 to disconnect the controller from a transmission line 4 and to short-circuit the line 4. Thus, even when the fault takes place in any controller, the function of the network is kept normally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmission network system.
Specifically, it relates to a data transmission network system that can maintain normal network functions even if a failure occurs in any one of the multiple network controllers that make up the network. [Prior Art] Figure 8 shows a conventional data transmission network system. This includes a plurality of network controllers 101, . . . 101 connected in a loop through a transmission line 104.
．． It is composed of. Each network controller 1
01+ to 101, are C connected through the bus 111.
PUII2, ROM113, RAM114, I/011
5 and I/0116. I/011
A host computer or terminal is connected to 5.
The transmission line 104 is connected to I/0116. Each network controller 1011-101. CP of
The U 112 takes in the command sent through the transmission line 104 via the I/0 116, and determines whether the address included in the command is its own address.
If it is not your own address, send the command to I/011.
6 to the next network controller (in FIG. 8, the counterclockwise network controller). On the other hand, if it is its own address, the process for that command will be executed. [Problems to be Solved by the Invention] In the conventional system, because of the above-mentioned configuration, all the network controllers 101. ~l01. The network is constructed on the condition that the is functioning normally. Therefore, the network controllers 1011 to 101 . If even one of them fails, the entire network will be affected and become unusable. Regarding the network controller 101. If the power goes down and the CPU 112 is no longer able to operate normally, it will not be able to receive commands sent through the transmission line 104, and as a result, the commands will not be able to be sent to the next network controller 101, so the entire network will not function properly. It will stop and become unusable. The purpose of the present invention is to solve such conventional problems and to maintain normal network functions even if a failure occurs in any one of the multiple network controllers that construct the network. The objective is to provide a data transmission network system that can maintain [Means for Solving the Problems] Therefore, in the present invention, in a data transmission network system including a plurality of network controllers connected in a loop through a transmission line and capable of mutually transmitting data, each of the network controllers is connected to its network. switching means capable of connecting the controller in series in the transmission line, disconnecting the network controller from the transmission line and short-circuiting the transmission line; an abnormality detection means for detecting an abnormality in the network controller; and control means for switching the switching means to disconnect the network controller from the transmission line and short-circuit the transmission line when the transmission line is detected. [Operation] If an abnormality occurs in any one of the multiple network controllers that make up the network, the abnormality will be detected by the abnormality detection means of that network controller. Then, the control means switches the switching means to disconnect the network controller from the transmission line and short-circuit the transmission line. Therefore, the network controller in which the abnormality occurs is disconnected from the transmission line, and the transmission line enters a closed loop state, so that even if a failure occurs in any one network controller, the network functions can be maintained normally. Can be done. [Example] Hereinafter, the present invention will be explained in detail based on an example shown in FIGS. 1 to 7. Figure 7 shows the system of this embodiment. The system consists of a plurality of network controllers 1.1 connected in a loop through a transmission line 4 and capable of transmitting data to each other. ~
1. If you keep one of them, it will be connected to the network controller 11 and the network controller 1. and a host computer 2 capable of data transmission, and other network controllers 12 to 1 . connected to each? The network controllers 12 to 1, and a plurality of terminals 3 capable of data transmission. 、． 3■2-31,3. , 2. FIG. 1 shows each of the network controllers 11 to 1. The block diagram is shown. In the same figure, 11 is the CPU
It is. The CPU 11 is connected to a ROM 13 storing programs, a RAM 14, and an I/O through a 16-bit bus 12.
/015, I/016, communication I/017, said CPU
A watchdog timer 18, etc., which checks if the II runs out of control, is connected to each. Note that these circuits are
Even if the power is turned off, the battery 19 is used for backup for a predetermined period of time (approximately 5 minutes) after the power is turned off, so that normal operation can continue. Further, when the power is turned off, this is detected by a power failure detection circuit 20 constituting an abnormality detection means, and an interrupt signal is given to the CPUll. Here, in addition to a data storage area for storing data, the RAM 14 includes each network controller 1. ~1. An address storage area 14A is provided for storing addresses of . In addition, the above I
/015, the host computer 2 and each terminal 32
1.322~31+3.2 can be connected. In addition, the I/016 has an error lamp “R”.
A control panel 21 is connected to which a "EADY" rung and other necessary keys and switches are arranged.Furthermore, the transmission line 4 is connected to the communication ■/017 via a switching means 22.Switching The means 22 is for communication 1
/Ol7 is connected in series to the transmission line 4, and the CPU II based on the interrupt signal is connected through the OR circuit 23.
When a switching command is given from the watchdog timer 18 or from the watchdog timer 18, the switching operation is performed to disconnect the communication 1/017 from the transmission line 4 and short-circuit the transmission line 4. Figure 2 shows the specific structure of the switching means 22. The switching stage 22 includes switches 31A and 31B respectively provided between the input measuring terminal 4A and the output measuring terminal 4B of the transmission line 4 and the input terminal 17A and output PIJ terminal 17B of the communication I/017, Switch 31A, 31B when energized
An excitation coil 32 that energizes the input measuring terminal 17A and the output side terminal 17B of the communication I/O 17, and the CPU II
and a controller 33 that controls energization of the excitation coil 32 according to a switching command from a watchdog timer l8, and a controller 33 that controls energization of the excitation coil 32 in accordance with a switching command from a watchdog timer l8, and a controller 33 that controls energization of the excitation coil 32 when the switches 31A and 31B return in a direction away from the input terminal 17A and the output terminal 17B. 31B, and a short-circuit circuit 34 that short-circuits between 31B and 31B. Note that the CPU II executes the processes shown in the flowcharts shown in FIGS. 3 to 6 according to the program stored in the ROM 13. Here, CPUI1 and R
The OM 13 constitutes a control means that executes these processes. Next, the operation of this embodiment will be explained with reference to the flowcharts of FIGS. 3 to 6. When constructing a network, a network controller (main network controller) that has control over the entire network is required.
The condition is that there is one. Here, suppose we are talking about network control? Controller 1l is the main network controller, and other network controllers 1-1. We will proceed with the explanation assuming that is a subnetwork controller. (Main network controller) The CPU 11 of the main network controller 1 is
When the power is turned on, the process is executed according to the flow chart shown in FIG. 3, and when an interrupt signal is given from the power failure detection circuit 20, the process shown in the flow chart shown in FIG. 4 is executed. First, when the power is turned on, initial processing is performed in step (hereinafter abbreviated as ST) 1 in Figure 3.
For example, connect the switches 31A and 31B of the switching means 22 to terminal 1.
7A. After switching to 17B, the process proceeds to ST2, where self-diagnosis processing is performed.6For example, the RAM 1.4 and ROM 13 are checked, and the voltage level of the backup battery of RAM 14 is checked. Next, the process proceeds to ST3, where the loop initial command is sent to the transmission line 4, and the process waits for reception of the loop initial command in ST4. Here, Loupini? If the manual command is received, that is, if it is confirmed that the network has been constructed, the process proceeds to ST5, where the "READY" lamp on the control panel 21 is turned on, and then the process proceeds to ST6, where the sub-network controllers 11-1. Determine whether or not a registration request command has been received from. S'r”
6, if the registration request command is received, S
Proceeding to T7, it is determined whether the address included in the registration request command exists in the address storage area 14A. If there is no corresponding address, proceed to ST8 and register the address included in the registration request command in the address storage area 14A, then proceed to ST9 and send a registration permission command to the network controller that sent the registration request command, and then proceed to ST6. Return to. If there is a corresponding address in ST7, STIO sends a registration refusal command to the network controller that sent the registration request command, and then
Return to T6. If the registration request command is not received in ST6, the process advances to ST11 and the subnetwork controllers 12 to 1. Determine whether a registration cancellation command has been received from. If a registration cancellation command has been received, ST1
Proceed to step 2 to cancel the corresponding address from the address storage area 14A, then proceed to ST13, send a cancellation completion command to the network controller that sent the registration cancellation command, and then return to ST6. If the s'rii does not receive the registration cancellation command, the process advances to ST14 and executes the data transmission process, that is, the original data transmission task. On the other hand, if an interrupt signal is received in the middle of these processes, the process proceeds to S'r'21 in FIG. 4, and a command to relinquish control is transmitted, and in ST22, one of the subnetwork controllers 12 to l. Waits for a command to accept control from. When the control right acceptance command is received, that is, when it is confirmed that the control right has been accepted by one of the subnetwork controllers, the process proceeds to ST23 and a registration cancellation command is sent, and in ST24 the network controller to which the control right has been transferred (in this case , which will become the main network controller from now on) waits for the cancellation completion command. Here, when the cancellation completion command is received, the process proceeds to ST25 and the switching means 22 is turned off. That is, the excitation coil 32 is de-energized via the controller 33. Then, the switches 31A and 31B switch to the terminals 17A and 31B.
17B and is short-circuited through the short-circuit circuit 34. As a result, the network controller II in which the abnormality has occurred is disconnected from the transmission line 4, and the transmission line 4
The network is maintained normally because it is short-circuited. At the same time, control [i is transferred to another network controller, so that network controller 1, when it rejoins the network, functions as a subnetwork controller. <Subnetwork controller) CPUI of each subnetwork controller 12 to 1
When the power is turned on, I executes processing according to the flowchart shown in FIG.
When an interrupt signal is given from , the process shown in the flowchart shown in FIG. 7 is executed. First, when the power is turned on, initial processing is performed in step (hereinafter abbreviated as ST) 31 in FIG.
After switching to terminals 17A and 17B, the process advances to ST32 and self-diagnosis processing is performed. If you delete it, RAM14 and ROM1
3 and check the voltage level of the RAM14 backup battery. Next, proceed to ST33, and after transmitting the registration request command to the transmission line 4, proceed to ST34.3.
Proceed to 5. Main network controller 1. Wait for the registration permission command or registration refusal command from . ST3
In step 5, upon receiving the registration refusal command, ST36
Proceed to turn on the error lamp on the control panel 21, then turn off the switching means 22, and then exit.
Therefore, in this case, you cannot participate in the network. Also, in ST34, when the registration permission command is received, the process advances to ST38 and the “RE” on the control panel 2l is
After lighting the "ADY" lamp, it is determined in ST4 0 whether or not a command to relinquish control rights has been received. If the command to relinquish control rights has not been received, the process advances to ST4 1 and the original data transmission task is executed. Therefore, it is possible to participate in the network, that is, to execute the original data transmission task, on the condition that the registration permission command is received from the main network controller 11.
If the control relinquish command is received in the ST
After proceeding to ST42 and transmitting a control right acceptance command to the main network controller II, proceeding to ST43 and performing processing as the main network controller, that is, ST6 to ST14 in FIG. 4 and ST21 to ST2 in FIG.
Perform the process in ST25. Therefore, if a failure occurs in the main network controller l1 and it relinquishes control, any of the other subnetwork controllers 12 to 1. takes over the control rights and functions as the main network controller. On the other hand, when an interrupt signal is given from the power failure detection circuit 20, the process proceeds to ST51 in FIG. 6, where a registration cancellation command is sent, and the process waits for a cancellation completion command from the main network controller II in ST52. When the cancellation completion command is received, the switching means 22 is turned off and the process ends. Therefore, in this case as well, the network controller in which the abnormality has occurred is disconnected from the transmission line 4, and the transmission line 4 is short-circuited, so that the network is maintained normally. Therefore, according to this embodiment, a plurality of network controllers 11 to l. If an abnormality occurs in any one of the network controllers, that network controller is disconnected from the transmission line 4 and the transmission line 4 is short-circuited, so even if a failure occurs in the network controller, It is possible to maintain normal network functions. In addition, other network controllers 12 to 12 other than network controller 1, which has network control authority,
1. The self address is network controller I
Since each network controller can participate in the network at any time, it is possible to participate in the network on the condition that it is registered in the address storage area 14A of I and receives the f-recording permission command from the network controller 11. For example, each network controller can participate in the network at any time. Even if each network controller is located in a separate location and power cannot be supplied to all network controllers at the same time, a network can be constructed simply by turning on the power to the necessary network controllers. In addition, if an abnormality occurs in network controller 1, which has the right to control the network, the control right is transferred to another network controller, and from then on that network controller functions as the main network controller. It is possible to maintain normal network functions even in the event of a controller failure. [Effects of the Invention] As described above, according to the present invention, when an abnormality occurs in any one of the plurality of network controllers constructing a network, that network controller is disconnected from the transmission line and the transmission is stopped. Since the line is short-circuited, the network function can be maintained normally even if a failure occurs in the network controller.

[Brief Description of the Drawings] Figures 1 to 7 show one embodiment of the present invention.
Figure 2 is a block diagram showing each network controller, Figure 2 is a diagram showing the switching means, Figure 3 is a main flowchart in the main network controller, Figure 4 is a flowchart of interrupt processing in the main network controller, and Figure 5 is a diagram showing other network controllers. Figure 6 is a flowchart of interrupt processing in another network controller.
Figure 7 is a block diagram showing the entire system. Figure 8 is a block diagram showing a conventional system. ■, ~1. ...Network controller, 4...
Transmission line, 11.13...CPU and ROM (control means),
20... Power outage detection circuit (abnormality detection means), 22...
Switching means.

Claims (1)

[Claims] (1) In a data transmission network system comprising a plurality of network controllers connected in a loop through a transmission line and capable of transmitting data to each other, each of the network controllers is capable of connecting its network controller in series to the transmission line, and a switching means capable of disconnecting the network controller from the transmission line and short-circuiting the transmission line; an abnormality detection means for detecting an abnormality in the network controller; and a switching means for switching the switching means when the abnormality detection means detects an abnormality. A data transmission network system comprising: control means for disconnecting the transmission line from the transmission line and short-circuiting the transmission line.