JPH0563716A - Reply confirming system for ring bus - Google Patents

Abstract

PURPOSE:To identify the responding state of each node by providing a part for displaying a responding state in a frame and allowing each communication node to set the display location of the responding state allocated to itself to a state representing normal reception when each node receives a signal normally. CONSTITUTION:A communication management node sends a frame 1 including a responding state display part 2 to a global address as a communication destination. The reception section 10 of a communication node receives a frame 1 and when a frame analyzing means 11 detects an address including its own communication node, the means 11 stores a frame into a frame buffer 1 to drive a responding state display bit setting means 13. When a state signal representing normal reception from a terminal equipment 14 is received, the means 13 sets information representing the normal reception to the display location of its own node in the display part 2 and sends the information to a ring bus from a transmission section 15 via a buffer 12. The information is similarly processed even in the communication node of downstream and a communication management node receives the information finally and identifies the responding state depending on the display part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring bus response confirmation system in which a plurality of communication nodes are connected to a ring bus.

In a ring network system in which communication nodes having a data transmission / reception function are connected by a ring bus,
One communication node is assigned as a communication management node for managing the system and manages communication. In such a ring bus, the communication management node may transmit to a plurality of communication nodes at the same time, but the plurality of communication nodes that have received the communication must individually send a response confirmation to the communication management node. I won't.

[0003]

2. Description of the Related Art FIG. 5 is an explanatory view of a conventional example. A. of FIG. Is a ring network configuration, and B. Is the frame structure.

A. In the figure, 50 to 55 are general communication nodes, 56 is a communication management node having a function of controlling a plurality of communication nodes and ring buses, and 57 and 58 are ring buses for connecting the respective communication nodes. In this configuration, two ring buses 57 and 58 are provided, but one (for example, 57) can be used as the current one and the other (for example, 58) can be used as a spare when the current one is in failure. The ring bus provided with n spares is called a ring bus of n + 1 configuration.

In this ring network, a communication node that captures one token circulating on the ring bus acquires the data transmission right and transmits the transmission data to another communication node. Communication types between communication nodes include one-to-one communication and one-to-n communication.

FIG. 5B. The frame structure used for communication between communication nodes is shown in, is a frame for transmitting a command, and is a frame for transmitting data. In these frames, F is a flag (8 bits of 01111110), C is a command, DA is a communication destination address, SA is a source address, FCS is a frame check sequence for error detection, and I is data to be transmitted. Is an information field in which is stored.

As the communication type, one-to-one communication and one
In the representative address for communication to n, the source is one communication node, and the destination is one communication node (one-to-one) or a plurality of nodes belonging to the representative address. The address or representative address of the partner communication node is set as the specific communication destination address in the destination address (DA) of the frame shown in FIG. When the transmitted frame is received by the communication destination (or multiple communication destinations in the case of a representative address), the frame is picked up by the corresponding node, and an ACK frame indicating that it has been received on the ring bus is addressed to the transmission source communication node. To send. When the transmission source receives this, it can be confirmed whether or not the frame is normally transmitted to the communication destination. Also,
When the destination communication node cannot receive due to buffer busy, etc., the REJ (reject) frame is returned to complete the communication.

On the other hand, in a one-to-n communication, a group global address having a relatively large number of communication nodes as communication destinations,
When an all global address is set and transmitted, a frame is received by a plurality of communication nodes forming a group, and in the case of an all global address, all communication nodes receive the frame. In this case, when a plurality of communication nodes that have normally received each employ a method of transmitting an AKC (response confirmation) frame to a transmission source (which may be a communication management node), a large number of communication nodes are used. When all send ACK frames (or REJ frames) all at once, it takes a lot of time for each communication node to acquire a token and send a frame, during which the ring bus is occupied for sending and receiving AKC frames. Therefore, conventionally, when an address with such a large number of communication nodes as the communication destination is used, the transmission of the response confirmation frame is omitted.

[0009]

In the communication addressed to a large number of communication nodes such as the group global address and the all global address as described above, the transmission source performs the transmission and then the reception is performed by the plurality of communication destinations. However, in some communication nodes, reception may not be possible due to buffer busy or communication node failure. As described above, the plurality of communication nodes do not return the response frame in the same manner whether the reception is normal or not, so that there is a problem that the transmission source cannot confirm the communication. Further, this causes a problem that the reliability of the system is lowered.

It is an object of the present invention to provide a ring bus response confirmation method that enables confirmation of a response without requiring extra procedures and time even in communication using global and all-global addresses.

[0011]

FIG. 1 illustrates the principle of the present invention. In FIG. Is a frame structure when a global address (group global address, all global address, etc.) according to the present invention is used, 1 is a frame, and a flag (F) indicating a frame start, a command (C), a communication destination address ( DA), source address (SA), information field (I), frame check sequence (FCS), and flag (F) indicating the end of frame. Reference numeral 2 is a response status display section, and when a global address is set as a communication destination address, whether or not reception is normal at each of the plurality of communication nodes corresponding to the global address provided in the information field (I) in the frame This is an area for setting the display of.

B. Is a principle diagram of a communication node, 10 is a receiving unit, 11 is a frame analysis means, 12 is a buffer, 1
3 is a response status display bit setting means, 14 is a terminal including a processor, and 15 is a transmission unit.

The present invention provides a response status display portion for displaying a response status assigned to each communication node in a frame sent to a large number of communication nodes by a global address. When a frame is normally received, the display position of the response state assigned to itself is set to a state indicating normal reception so that the response state of each communication node can be immediately identified when the frame returns to the transmission source. ..

[0014]

Operation: The communication management node sets the global address as the communication destination (DA), and the response status display section 2 is set in the information field.
The frame 1 including is transmitted. When the frame 1 is received by the receiving unit 10 of the communication node, the frame analysis unit 11 analyzes the address and, when it is detected that the global address includes the own communication node as a destination, stores the frame in the frame buffer 12. At the same time, the response status display bit setting means 13 is driven. The contents of the frame buffer 12 are sent to the terminal 14 and processed by the commands and data in the frame. On the other hand, when the response status display bit setting means 13 receives the normal reception status signal from the terminal 14, the information indicating the normal reception is displayed at the display position assigned to the own communication node in the response status display unit 2 in the frame buffer 12. For example, the bit "1") is set. At first, the display position for each communication node of the response status display unit 2 is initially set with information (for example, bit “0”) indicating an abnormal state, and if normal reception is not possible, the contents of the display position are changed. Good if not.

When the setting of the response status display is completed, the frame of the frame buffer 12 is transmitted from the transmitter 15 to the ring bus. Similar processing is performed in the communication node downstream of the ring bus, and when finally received by the communication management node of the transmission source, the display position corresponding to each communication node of the response status display unit 2 in the frame is identified. This makes it possible to determine which communication node has not received (or has failed).

[0016]

FIG. 2 is a block diagram of a communication node of the embodiment, FIG. 3 is a processing flow in the communication node, and FIG. 4 is a diagram showing an example of a setting operation by a frame including a response status display section.

In FIG. 2, reference numeral 20 is a communication node, 21 is a ring bus interface for processing to receive a signal from an upstream communication node, and 22 is an identification of whether a frame is a token or a normal frame. , A frame analysis unit that analyzes control signals contained in the frame, that is, addresses, commands, etc., 23 is a frame that needs to be received from an upstream communication node and sent to another communication node, or when transmitting a frame from its own communication node Is a transmission control unit that controls switching of the transmission data switching unit 26.

Reference numeral 24 is a switching unit for switching between bypassing the frame received from the upstream side when the communication node has a failure and transmitting it to the downstream communication node, or transmitting the frame from the ring bus interface 25 when there is no failure. Reference numeral 25 is a ring bus interface on the transmission side that performs processing for transmission to a downstream communication node, 26 is a transmission data switching unit that selects either the frame from the frame analysis unit 22 or the frame generated from the own terminal, 27 Is a processor interface unit for interfacing the communication node with the processor (terminal) side, 28 is a processor of the terminal, and 29 is a memory of the terminal.

The operation of FIG. 2 will be described with reference to the processing flow of FIG. When a frame in which a global address is set is input and the frame is received by the ring bus interface 21 (30 in FIG. 3), the frame analysis unit 22 analyzes the frame (31). At this time, it is judged whether or not the communication destination address (DA) displays a global address (at 32), and if it is not a global address, normal processing is performed (at 33). That is,
If the frame is addressed to the own communication node, the frame is fetched and a response confirmation frame is transmitted. If the frame is not addressed to the own communication node, the transmission control unit 23 switches the transmission data switching unit 26 to switch the frame analysis unit 22 and the transmission data switching unit 26. ，
It is transmitted via the ring bus interface 25 and the switching unit 24.

When the address is a global address, the frame analysis unit 22 notifies the processor 28 through the processor interface unit 27. The processor 28 controls the DMA transfer of the received frame to the memory 29 via the processor interface unit 27 (step 34). The processor 28 decodes the command (C) in the frame transferred to the memory 29 and performs a corresponding process (step 35).
Next, the processor 28 sets "1" in the response status indication bit for its own node provided in the information field of the frame stored in the memory 29 (at step 36), and resets the contents of FCS by calculation. When a frame is formed by performing the processing of (1), a transmission instruction is issued to the transmission control section 23 via the processor interface section 27 (see 3 above).
7). As a result, the transmission data switching unit 26 is switched,
The frames in the memory 29 are transferred by DMA, and the processor interface unit 27 and the transmission data switching unit 26
Is transmitted to the ring bus through the ring bus interface 25 and the switching unit 24 (step 38).

A concrete example of the frame structure and an example of the setting operation will be described with reference to FIG. A. of FIG. As shown in FIG. 5, a response status display section is provided at the beginning of the information field I in the frame, and in this example, it is composed of 16 bits (2 bytes). The 16-bit bit positions 0 to 15 are assigned as the response status indication bits of the communication nodes,
All are set to "0" when sent from the source communication node (communication management node mainly uses global address), and set to "1" sequentially when received normally at each communication node, and received When it is not possible or when there is an abnormality (when an error is detected), "0" is maintained.

FIG. 4B. Shows the setting operation of the response status display unit in the example of the ring network in which the five communication nodes represented by # 1 to # 5 and the communication management node represented by # 7 are connected by the ring bus.

In this example, when 100 frames at the global address are first transmitted from the communication management node, they are supplied to the communication node # 1 via the ring bus.
When the frame 101 is normally received, the frame 101 in which the first bit assigned to the communication node # 1 in the response status display section is set to "1" is transmitted to the ring bus.

When the next communication node # 2 receives this normally, it sets the second bit of the response status display section to "1" and transmits the frame 102 to the downstream ring bus. If the communication node # 3 cannot receive the frame due to a node failure or the reception buffer is busy, the third bit assigned to the own communication node in the response status display unit is not operated (remains "0"), and the frame 103 remains as it is. Send downstream. In the same manner, the communication frame # 5 is transmitted to the communication node # 5, and the communication frame is returned from the communication node # 5 to the communication management node # 7.

The communication management node # 7 determines whether or not the communication is normally received by determining the content of the response status display section at the time of receiving the frame that has made a round, and confirms with the communication node that cannot receive the communication. Communication is performed again by using the individual address, the state of the communication node is confirmed, it is determined whether it is a temporary failure or a fixed failure, and if it is a fixed failure, the system is disconnected from the system.

In this embodiment, the system adopting the token passing system of the ring bus is taken as an example. However, the same principle can be applied to other systems, such as global communication and broadcast communication.

[0027]

According to the present invention, in a ring network system in which a plurality of communication nodes are connected by a ring bus, response confirmation at the time of 1-to-n communication can be performed at high speed by a simple means, and at the same time, communication node failure Can be easily detected. Also, by confirming the response in the broadcast communication, it is possible to confirm whether or not the processing level of each communication node is the same, and it is possible to construct a more reliable ring network system.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of a communication node according to an embodiment.

FIG. 3 is a processing flow in a communication node.

FIG. 4 is a diagram showing an example of a setting operation by a frame including a response state display unit.

FIG. 5 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 frame 2 response status display unit 10 reception unit 11 frame analysis unit 12 buffer 13 response status display bit setting unit 14 terminal 15 transmission unit

Claims (2)

[Claims] 1. In a ring bus response confirmation method in which a plurality of communication nodes are connected by a ring bus, when a frame with a global address as a communication destination address is transmitted, it corresponds to the global address in the information field of the frame. A response status display unit including display positions for each communication node in a number corresponding to the number of communication nodes is provided, and each communication node corresponding to each global address that has received the frame has its own address in the response status display unit during normal reception. A ring bus response confirmation method that sets a display indicating normal reception at the display position assigned to the communication node and sends it to the downstream ring bus. 2. The transmission source communication node according to claim 1, when a frame that has passed through a ring bus is received after transmitting a frame to which a global address is added, the communication node corresponds to each communication node in the response status display section in the frame. A ring bus response confirmation method characterized in that a communication node that is not normally received is identified by identifying the content of the display position of the response state.