JPH04192644A - Network system - Google Patents

Abstract

PURPOSE:To attain the communication by other slave station normally by giving control information to interrupt power supply to a slave station in which a fault of leaving a burst signal sending and locking the system when the burst signal having left sending is stopped. CONSTITUTION:A master station is provided with connection/disconnection control information transmission means 4, 5, 61-6N sending the information to control connection/disconnection of a power supply of a transmission section of each slave station to each slave station and a slave station fault detection means 2 detecting a fault of a slave station based on a reception time length of the information sent from a slave station. Moreover, the master station is provided with a control means 3 controlling the means 4, 5, 61-6N when a fault is detected to allow the slave station to send the control information of power supply connection/disconnection and terminating the transmission when the means 2 does not detect the fault. Thus, the control information to interrupt power supply of the slave station in which a fault of leaving a burst signal sending is given and the system is locked when the burst signal having left sending is stopped to implement the communication normally by other slave stations.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a network system such as a LAN (Local Area Network) system, and in particular, the present invention relates to a network system such as a LAN (Local Area Network) system, and in particular, the present invention relates to a network system such as a LAN (Local Area Network) system, in which information transmission from a slave station to a master station is burst type. The present invention relates to a network system implemented using the transmission method.

(Prior Art) For example, in a LAN system, as shown in FIG. 3, a system in which a master station P and a plurality of slave stations 01 to CN are connected in a loop through a transmission path is known. As shown in Figure 4, this system uses TDMA (time division multiplexing) to transmit information (downstream transmission) from the master station P to the slave station C.
A burst type transmission method is known in which information transmission (upstream transmission) from a slave station C to a master station P is performed using a burst type transmission method. In this case, each slave station C detects its own address in the data from the master station P, and after a predetermined period of time, transmits a burst signal of a predetermined length.

The above-mentioned predetermined time and burst length are defined so that signals transmitted by each slave station C will not collide.

(Problem to be Solved by the Invention) However, if one of the slave stations C experiences a failure and continues to emit burst signals, not only the slave station in question but also other slave stations C may be unable to transmit due to signal collision. There was a problem that caused the system to go down.

The present invention has been made to solve the problems of such conventional network systems, and its purpose is to ensure that even if a slave station has an abnormality in which it stops transmitting burst signals, a normal slave station can continue to transmit burst signals. The objective is to provide a network system that enables communication.

[Structure of the Invention] (Means for Solving the Problems) In the network system according to the present invention, a master station and a plurality of slave stations are connected via a transmission path, and each slave station transmits information to the master station. is a network system in which the transmission is performed using a burst type transmission method, and the master station includes close call control information transmitting means for transmitting information for controlling the close contact of the power supply of the transmitter of each slave station to each slave station. and a slave station abnormality detection means for detecting a slave station abnormality based on the reception time length of information sent from the slave station, and when the slave station abnormality detection means detects an abnormality, the close talk control information transmitting means. control means for transmitting control information for power-off and power-on, and for terminating the transmission when the slave station abnormality detection means no longer detects an abnormality; , a power supply circuit that supplies power to a transmitter that transmits transmission information using a burst-type transmission method; and a power supply circuit that detects power disconnection information from information sent from the master station, and based on this, the power supply circuit The present invention is characterized by comprising a power supply control means for controlling supply.

(Function) According to the network system having the above configuration, control information to cut off the power supply from the power supply circuit of the transmitting section is given to the slave station that has an abnormality of continuously outputting burst signals, and thereby the burst signal is stopped. When the release stops, it is locked and other slave stations can communicate normally.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of main parts of the master station P.

A burst signal transmitted from slave station C is given to burst length detection circuit 1 in addition to the information processing system. The burst length detection circuit 1 increments a counter when a burst signal is input, and resets it when the burst signal disappears, but when the burst signal reaches a length that causes a collision, the output of the counter becomes H level and is provided to the abnormality determination circuit 2. Abnormality determination diagram 1
i42 has a function of latching an H level signal. When the output of the abnormality determination circuit 2 becomes H level, the slave station power supply control unit 3 first selects the output of the break code generating unit 4 in order from the slave station C1 transmission selection unit 61 to the slave station CN transmission selection unit 6N. , then select the output of the contact code generator 5,
Take control over selection.

That is, first, when the slave station C1 transmission selection section 61 selects the output of the broken code generation section 4, the output of the 1 frame 1 middle station 01 in FIG.
The cut code is inserted as line information and sent. Therefore, the slave station power control unit 3 monitors the output of the abnormality determination circuit 2,
If it is still at H level, the slave station C1 transmission selection section 61 selects the output of the close code generation section 5, and the slave station C2 transmission selection section 62 selects the output of the disconnection code generation section 4. As a result, the connection code is inserted as the information in the 01 row of the slave station in one frame in FIG. 4, and the disconnection code is inserted as the information in the slave station C2 row. Therefore, the slave station power control section 3 uses the abnormality determination circuit 2.
The output is monitored, and if it remains at H level, the same operation continues. While this operation continues, the transmission section of the slave station that has been transmitting burst signals is turned off due to an abnormality, and the transmission of burst signals stops and the output of burst length detection circuit 1 goes to L level. Returning, the output of the abnormality determination circuit 2 also becomes L level. The slave station power supply control section 3 detects this, and in this state, the subsequent transmission of the disconnection cord and connection cord ends.

FIG. 2 shows a block diagram of a slave station C according to an embodiment of the present invention. The transmitter 14 in the figure transmits information from the own station as a burst signal after a predetermined period of time after a receiver (not shown) detects the address for the own station. This transmitter 14 is supplied with power from a transmitter power supply circuit 13 . On the other hand, the received data to which the address of the own station has been added is given to the information processing system, and is also given to the broken code detection section 11 and the connected code detection section 12. When the broken code detection unit 11 detects a broken code sent from the master station P, it sends a control signal to the transmitter power supply circuit 13 to stop the power supply. When the contact code detection unit 12 detects the contact code sent from the master station P, it
3, a control signal is sent to restart the power supply. With this configuration, power supply can be controlled by transmitting disconnection cords and connection cords from the master station P. If an abnormality occurs in which the burst signal continues to be output, a disconnection code is sent to the transmitter 1.
The power supply to the slave station C is stopped and the burst signal is no longer transmitted, and the master station P detects that the slave station C is abnormal and locks in this state. That is, the connection cord is not transmitted, and the power supply remains stopped.

In addition, in the above embodiment, the disconnected code and the connected code are sequentially transmitted to successive slave stations, but only the disconnected code is transmitted to the slave stations sequentially, and when reception of the burst signal stops, the disconnected code until then is transmitted to the slave stations sequentially. The access code may be sent to all normal slave stations that have sent the code. Further, the shape of the network may be other than loops.

[Effects of the Invention] As explained above, according to the present invention, control information for cutting off the power supply from the power supply circuit of the transmitting section is given to a slave station that has an abnormality of continuously emitting burst signals. As a result, when the output of burst signals stops, the device is locked, and other slave stations can communicate normally.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of a master station according to an embodiment of the present invention, FIG. 2 is a block diagram of main parts of a slave station according to an embodiment of the present invention, and FIG.
The figure is a block diagram of a system to which the present invention is applied, and FIG. 4 is a diagram showing uplink burst type/downlink time division multiplexing type communication procedures. P...Master station C1~CM...Slave station 1...
・Burst length detection circuit 2...Abnormality determination circuit 3...Slave station power supply control section 4・
...Break cord generation section 5...Connection cord generation section 61-6
N...Slave station C transmission selection unit 11...Disconnected code detection unit 12...Connected code detection unit 13...Transmission unit power supply circuit 14...Transmission unit agent
Patent Attorney Nori Ken Chika Yudo Sanno - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A network system in which a master station and a plurality of slave stations are connected via a transmission path, and information transmission from each slave station to the master station is performed by a burst-type transmission method, comprising: A connection/disconnection control information transmitting means for transmitting information for controlling the connection/disconnection of the power supply of the transmitter of each slave station to each slave station, and a connection/disconnection control information transmitting means for transmitting information for controlling the connection/disconnection of the power supply of the transmitter of each slave station, and a slave station abnormality detecting means for detecting a station abnormality; and when the slave station abnormality detecting means detects an abnormality, the connecting/disconnecting control information transmitting means is controlled to transmit power-off and power-on control information; and control means for terminating transmission when the slave station abnormality detection means no longer detects an abnormality, and each slave station is provided with power to a transmitter that transmits transmission information using a burst type transmission method. and a power supply control means for detecting power supply disconnection information from information sent from the master station and controlling power supply by the power supply circuit based on the information. network system.