JP2006270447A - System and method for broadcast communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for broadcast communication that can specify a slave communication node where abnormality occurs during broadcast communication in such a case through confirmation answer communication and optionally designate a destination of communication without any increase in processing load on a communication node. <P>SOLUTION: When command data (b) to which a broadcast address is added as a device ID are transmitted, a confirmation answer display portion 41 is provided in a status data frame 40. A slave communication node corresponding to the broadcast address makes settings representing a normal answer at display positions S1 to S7 allocated to the communication node in the confirmation answer display portion 41 at the time of normal reception. When normal reception ends in failure or when a processing state is reported to a master communication node, specified settings are made and a plurality of slave communication nodes simultaneously transmit status data (c1) to (c7) to the master communication node in synchronism with a clock (a) for data transmission synchronization. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a broadcast communication system and method, and more particularly to broadcast communication between a master communication node and a plurality of slave communication nodes in a bus interface in which a master communication node and a plurality of slave communication nodes are connected. Relates to a broadcast communication system and method.

  In a bus interface in which a master communication node and a plurality of slave communication nodes are connected, a broadcast communication system performed between the master communication node and a plurality of slave communication nodes includes a master communication node and a plurality of slave communication nodes. There is a first system that does not perform acknowledgment response to broadcast communications issued to the second system, and a second system that performs acknowledgment response communication.

  In addition, the second system for performing acknowledgment communication includes a method for sequentially transmitting confirmation responses from the slave communication node to the master communication node in time series, and a slave communication node using a dedicated signal line or address line. There is a method of grouping and sending confirmation responses to the master communication node in a lump.

  When outputting an acknowledgment signal for broadcast communication, the slave communication node on the receiving side outputs a low level signal to the response signal line as an abnormal response. Further, a signal that is not at a low level is output as a normal response. Therefore, the master communication node of the transmission source can know that the broadcast communication has not been normally completed when the level of the response signal line is low. At the time of individual transmission, the slave communication node on the receiving side outputs a low level normal response signal to the response signal line.

  However, in such a system, the master communication node of the transmission source cannot identify which slave communication node the reception abnormality has occurred. As an improvement of such a system, for example, there are systems described in Patent Document 1, Patent Document 2, and the like.

Japanese Patent Laid-Open No. 64-11438 JP-A-1-105634 JP-A-5-303537 JP-A-5-327733 JP 2000-69058 A

  However, the conventional broadcast communication system as described above has the following problems.

  In the first system that does not perform the confirmation response communication, it is impossible to confirm whether or not the broadcast communication can be reliably performed in the master communication node of the transmission source. In the method of performing acknowledgment communication by sequentially transmitting the acknowledgment signal from the slave communication node on the receiving side to the master communication node on the transmitting side, the acknowledgment signal is transmitted to each slave in time series. Since it is transmitted from the communication node, it takes a long time for the master communication node to receive the acknowledgment signals from all the slave communication nodes.

  Further, in the method of performing acknowledgment communication using a dedicated signal line, the number of signal lines for connecting between communication nodes has increased, and the number of circuits has increased, resulting in high costs.

  On the other hand, in the method in which the slave communication nodes on the receiving side are modularized (grouped) using an address line or the like and the acknowledgment signal is transmitted in a batch, when there is an increase in the number of communication nodes in the system, a single signal line is used for notification. When the number of slave communication nodes as confirmation response destinations increases and retransmission processing is performed when an abnormality occurs, other communication nodes belonging to the same group as the communication node in which the abnormality has occurred receive the same broadcast again. When the number of communication nodes per group increases, an extra retransmission operation is performed on a communication node in which no abnormality has occurred, and broadcast data is discarded in a communication node in which no abnormality has been received again. In the case of retransmission processing when an abnormality occurs, the efficiency of data re-transfer is reduced, and data transfer may take time, and it is difficult to improve the transfer speed.

  The present invention has been made in view of the problems of the conventional techniques as described above. It is an object of the present invention to specify a slave communication node in which an abnormality has occurred by means of acknowledgment communication when an abnormality occurs during broadcast communication, and arbitrarily designate a communication destination without increasing the processing load of the communication node It is an object to provide a broadcast communication system and method capable of performing broadcast communication.

  In order to achieve the above object, the invention according to claim 1 is characterized in that the master communication node and the plurality of master communication nodes are connected via a common bus through which a synchronization clock for data transmission is constantly transmitted from the master communication node to a plurality of slave communication nodes. In the broadcast communication system for performing broadcast communication between slave communication nodes, the common bus is a command for transmitting command data with data indicating broadcast communication from the master communication node to the plurality of slave communication nodes. Each of the plurality of slave communication nodes analyzes the received command data, and when the command data is received normally, a confirmation response of the status data for the confirmation response to the master communication node. Setting means for performing a setting for displaying normal reception on the display unit, and the common bus has the setting. Further comprising a status transmitting means for transmitting to each of the status data the is synchronized with the synchronization clock from said plurality of slave communication node to the master communication node.

  The invention according to claim 8 is the same between the master communication node and the plurality of slave communication nodes via a common bus through which a synchronization clock for data transmission is constantly transmitted from the master communication node to the plurality of slave communication nodes. In the broadcast communication method for performing broadcast communication, a command transmission step of transmitting command data with data indicating broadcast communication from the master communication node to the plurality of slave communication nodes via the common bus, In each of the slave communication nodes, the received command data is analyzed, and when the command data is normally received, normal reception is displayed on the confirmation response display section of the status data for confirmation response to the master communication node. A setting step for setting, and the status for each of the settings The chromatography data said synchronized with the synchronization clock from said plurality of slave communication node to the master communication node having status transmitting step of transmitting via the common bus.

  According to the above invention, when broadcast communication is performed, predetermined confirmation response display setting is performed on the confirmation response display unit provided for the own node in the status data, and synchronized with the clock signal transmitted from the master communication node. By transmitting, the master communication node can be notified of the data reception status and the slave communication node processing status.

  According to a second aspect of the present invention, in the first aspect of the invention, the master communication node receives the status data transmitted by the status transmission unit, and displays the confirmation response display unit of the status data. Analyzing means for determining whether there is a slave communication node that has not made a normal response according to the setting of the display unit, and the command transmitting means further includes the command with ID information unique to the node Data is transmitted from the master communication node to the slave communication node that has not made the normal response.

  According to a seventh aspect of the present invention, there is provided an image forming system using the system according to the first or second aspect, wherein the image forming apparatus forms an image on recording paper, and a paper feeding device or a discharge device connected to the image forming apparatus. And a control unit of the image forming apparatus includes the master communication node, and a control unit of the paper supply apparatus or the paper discharge apparatus includes the slave communication node.

  According to a ninth aspect of the present invention, in the eighth aspect of the present invention, after the status transmission step, the master communication node further analyzes the confirmation response display section of each received status data, and displays the display. A step of determining whether there is a slave communication node that has not made a normal response according to the setting of the unit, and the command data with ID information unique to the node is not sent from the master communication node A command retransmission step for transmitting to the slave communication node via the common bus.

  According to the above invention, when broadcast communication is performed, the master communication node as the data transmission source can confirm the reception status of the plurality of slave communication nodes connected to the common bus in one communication, and the slave communication node As a result of discriminating the confirmation response, data can be retransmitted only to the slave communication node in which an abnormality has occurred.

  According to the present invention, in a broadcast communication system in which a master communication node and a plurality of slave communication nodes are connected by a common bus, an acknowledgment of a slave communication node on the receiving side is sent to the master communication node on the transmission side during the broadcast communication. Can be received. Further, since the confirmation response can be received once within the broadcast communication time, the communication time can be shortened, and at the same time, the communication node failure can be easily detected.

  Furthermore, it is possible to confirm whether or not the processing levels of the slave communication nodes are the same by performing a confirmation response, and it is possible to construct a more reliable communication system.

(First embodiment)
Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a configuration of an embodiment of a broadcast communication system of the present invention.

  As shown in FIG. 1, the system of this embodiment includes a master communication node 10 that is a transmission side, a plurality of slave communication nodes 20-1 to 20-7 that are reception sides, a command data transmission line 30, and status data. It is composed of a common bus composed of a transmission line 31 and a transmission clock line 32. The master communication node 10 and the slave communication nodes 20-1 to 20-7 are connected by the command data transmission line 30, the status data transmission line 31, and the transmission clock line 32. Synchronous clocks for data transmission are transmitted toward the communication nodes 20-1 to 20-7, and in synchronization with this, the command communication data transmission line 30 sends master clock nodes 10 to slave communication nodes 20-1 to 20-20. Unidirectional communication to -7 and unidirectional communication from the slave communication nodes 20-1 to 20-7 to the master communication node 10 through the status data transmission line 31.

  The master communication node 10 includes data memory 11 that stores broadcast communication data to be transmitted to the slave communication nodes 20-1 to 20-7, and data to the slave communication nodes 20-1 to 20-7. And a receiving circuit 13 for receiving and processing data transmitted from the slave communication nodes 20-1 to 20-7. The slave communication nodes 20-1 to 20-7 each have a receiving circuit 21 for receiving data of the device ID of the own device or broadcast communication, and a data memory 22 for storing data received by the receiving circuit 21. And a transmission circuit 23 for processing data to be transmitted to the master communication node 10.

  In the broadcast communication system configured as described above, data including a broadcast address (global address, all-global address, etc.) indicating the start of broadcast communication from the master communication node 10 to the slave communication nodes 20-1 to 20-7. Send.

  FIG. 2 is a diagram showing a configuration example and principle of broadcast data transmitted from the master communication node 10 to the slave communication nodes 20-1 to 20-7 in the broadcast communication system shown in FIG. .

  In this embodiment, command data transmitted from the master communication node 10 to the slave communication nodes 20-1 to 20-7 is data including a device ID part 42 and a command data part 43 as shown in FIG. It has a structure. In this example, the device ID section 42 is composed of 3 bits, and consists of an ID of each slave communication node 20-1 to 20-7 or an ID indicating broadcast communication in order to identify a communication partner. In this example, the command data section 43 is composed of 11 bits and is composed of command data to be transmitted. In the device ID unit 42, when data is transmitted to a predetermined slave communication node, it becomes the ID of the slave communication node of the transmission destination, and when performing broadcast communication to the slave communication node, This is a broadcast ID (broadcast address) indicating broadcast communication. The slave communication node device ID is assigned by the master communication node 10 at the time of initial communication after power-on.

  As shown in FIG. 2C, the status data 40 transmitted from the slave communication nodes 20-1 to 20-7 to the master communication node 10 is provided with an acknowledgment display unit 41 in the data. The confirmation response display unit 41 is composed of 14 bits. Each 14-bit bit position is assigned as a response state display bit of each slave communication node, and the position and order thereof are determined by the slave communication node device ID assigned from the master communication node 10. This example is shown in FIGS. 2 (c1) to (c7). For example, the slave communication node 1 in FIG. 2C1 means the slave communication node 20-1.

The broadcast communication operation in the broadcast communication system having the above configuration will be described below.
FIG. 3 is a flowchart for explaining a broadcast communication operation in the broadcast communication system shown in FIG. FIG. 4A shows processing in the master communication node 10, and FIG. 4B shows processing in the slave communication nodes 20-1 to 20-7. FIG. 4 is a diagram schematically showing an operation flow when there is data that could not be normally received by a certain slave communication node in the broadcast communication system shown in FIG.

  When the data stored in the data memory 11 in the master communication node 10 is broadcast to the slave communication nodes 20-1 to 20-7, the broadcast circuit 12 adds a broadcast address to the device ID section 42 from the transmission circuit 12. Communication command data is transmitted as shown in FIG. 4A (step A40).

In the slave communication nodes 20-1 to 20-7, when the broadcast communication command data is received by the receiving circuit 21 (step B40), the received data is analyzed (step B41).
At this time, it is determined whether or not a broadcast address meaning broadcast communication is added, or whether or not a device ID specifying only the own node is added (step B42). If only the own node is designated, processing according to the command data is performed assuming that the communication is normal (step B47).

  If it is determined that the broadcast address is added, each of the slave communication nodes 20-1 to 20-7 transfers the command data to the memory 21 and performs the processing instructed by the stored command data (Step B43, B44). Next, the slave communication nodes 20-1 to 20-7 set "1" or "0" to 2 bits corresponding to the response status display section assigned to the own node of the status data configured for confirmation response (step). B45).

  In this embodiment, 2 bits are allocated to each of the slave communication nodes 20-1 to 20-7 (see (c1) to (c7) in FIG. 2), but the combination of the display positions S1 to 7S of 2 bits. “11” indicates normal reception, “01” or “10” indicates an arbitrary state, for example, normal reception, but a command indicated by command data cannot be executed, and “00” indicates normal reception. It becomes possible to express what could not be done. Of course, the number of bits is not limited to 2 bits, and 2 bits or more can be assigned.

  In addition, a bit of “1” or “0” is set in bits other than the confirmation response display unit allocated to the own node constituting the status data so as not to interfere with signals of other slave communication nodes.

  Next, the acknowledgment data is transmitted from the transmission circuit 23 in synchronization with the synchronous clock (FIG. 2A) always transmitted from the master communication node 10 (step B46). At this time, all slave communication nodes 20-1 to 20-7 connected to the common bus have no data transmission order, and status data is simultaneously transmitted in synchronization with the synchronous clock.

  After transmitting the command data for broadcast communication, the master communication node 10 receives an acknowledgment signal from the slave communication nodes 20-1 to 20-N connected to the common bus by the receiving circuit 13 (step A41). The status data is analyzed (step A42).

  Next, the master communication node 10 determines whether normal responses have been received from all the slave communication nodes 20-1 to 20-N (step A43), and normal responses are received from all the slave communication nodes 20-1 to 20-N. If it has been received, the broadcast communication is terminated (step A44).

  In step A43, if any one of the slave communication nodes has not been normally received, an individual device ID is newly added to the command data for the slave communication node that has not been normally received. Communication is performed as shown in FIG. 4C, and data that could not be received is transmitted (steps A45 and A46).

  In this embodiment, the command data transmission line 30 and the status data transmission line 31 are divided into two lines. However, since the data transmission clock is always transmitted from the master communication node 10, the command data transmission line 30 and the status data transmission line 31 are half-duplex communication. The transmission line 30 and the status data transmission line 31 may be shared by one bidirectional data line.

(Second Embodiment)
In this embodiment, an example in which the broadcast communication system of the first embodiment described above is applied to an image forming apparatus will be described.

  FIG. 5 shows an image forming apparatus, a paper feeding apparatus connected to the image forming apparatus, and a paper discharging apparatus.

  The image forming apparatus 100 forms an image on the recording paper P fed from the paper feeding devices 101 and 102 and discharges the recording paper P on which the image has been formed to the paper discharge device 103. The paper feeding apparatuses 101 and 102 are provided with a paper feeding roller 207 and conveying roller pairs 202 and 203, respectively. Further, the image forming apparatus 100 is provided with a pair of transport rollers 201 for receiving and transporting the recording paper P transported from the paper feeding apparatuses 101 and 102, and the recording paper transported by the transport roller pair 201 is provided. After being conveyed to the image forming unit 208 and forming an image on the recording paper P, it is discharged to the paper discharge unit of the image forming apparatus or discharged to the paper discharge device 103. The image forming apparatus 100 is provided with a flapper 209 that switches the conveyance path, and can switch whether the recording paper P is discharged to the paper discharge unit of the image forming apparatus or the paper discharge apparatus 103. . When discharged to the paper discharge unit of the image forming apparatus, the recording paper P is conveyed by the paper discharge roller pair 204 and discharged. When paper is discharged to the paper discharge device 103, the recording paper P is conveyed by the discharge roller pair 205. The paper discharge device 103 has a conveyance roller pair 206 that receives and conveys the conveyed recording paper P, and is configured to be able to move up and down a discharge tray (a discharge tray having six trays in the figure). The recording paper P is discharged to a desired tray.

Here, A in the figure is an image formation control unit that controls the operation of the image forming apparatus, B is a paper feed control unit that controls the operation of the paper feed apparatus 101, and C is a paper supply that controls the operation of the paper feed apparatus 102. A paper control unit D is a paper discharge control unit that controls the operation of the paper discharge device. The correspondence between these A, B, C, and D and the configuration of the first embodiment will be described with reference to FIG.
In FIG. 6, the master communication node 10 is an image forming control unit A, the slave communication node 20-1 is a paper feed control unit B, the slave communication node 20-2 is a paper feed control unit C, and the slave communication node D is a paper discharge control unit. Corresponds to D.
With this configuration, it is possible to apply the above-described broadcast communication system between the image forming apparatus and the sheet feeding apparatus and the sheet discharging apparatus connected to the image forming apparatus. It is possible to shorten the communication time of command and status communication between devices, and at the same time, it is possible to easily detect a communication abnormality.

  Note that the description of each communication node is the same as that of the first embodiment, and a description thereof will be omitted.

It is a block diagram which shows the structure of the broadcast communication system which shows one Embodiment of this invention. It is a figure which shows the principle of operation of this invention. 3 is a flowchart for explaining a broadcast communication operation in the broadcast communication system shown in FIG. 1. It is a figure for demonstrating operation | movement when the data which could not be received normally in a certain slave communication node in the broadcast communication system shown in FIG. It is a figure for demonstrating the image forming apparatus in the 2nd Embodiment of this invention. FIG. 6 is a diagram when a broadcast communication system is applied to an image forming apparatus according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Master communication node 11 Master communication node data memory 12 Master communication node transmission circuit 13 Master communication node reception circuit 20-1 to 20-7 Slave communication node 21 Slave communication node reception circuit 22 Slave communication node data memory 23 Slave communication node Transmission circuit 30 Command data transmission line 31 Status data transmission line 32 Clock transmission line 40 Status data frame 41 Confirmation response display section 42 Broadcast address 43 Command data

Claims (11)

Broadcast communication system for performing broadcast communication between the master communication node and the plurality of slave communication nodes via a common bus through which a synchronization clock for data transmission is constantly transmitted from the master communication node to the plurality of slave communication nodes In
The common bus comprises command transmission means for transmitting command data with data meaning broadcast communication from the master communication node to the plurality of slave communication nodes,
Each of the plurality of slave communication nodes analyzes the received command data, and when the command data is received normally, the slave communication node normally receives the confirmation response status data for the confirmation response to the master communication node. Comprising setting means for setting to display
The common bus further includes status transmission means for transmitting the set status data from the plurality of slave communication nodes to the master communication node in synchronization with the synchronization clock. . The system of claim 1, wherein
The master communication node receives each status data transmitted by the status transmission means, analyzes the confirmation response display unit of the status data, and performs a normal response according to the setting of the display unit A determination means for determining whether there is a slave communication node that did not exist;
The command transmission means further transmits the command data with ID information unique to the node from the master communication node to a slave communication node that has not made the normal response. The system of claim 2, wherein
The master communication node comprises storage means for storing the data indicating the broadcast communication or the command data with the ID information and the received status data. The system of claim 1 or 2,
Each of the plurality of slave communication nodes includes storage means for storing the received command data and the status data transmitted by the status transmission means. The system of claim 1 or 2,
The system characterized in that the command transmission means and the status transmission means are independent means. The system of claim 1 or 2,
The command transmission unit and the status transmission unit are common units. An image forming system using the system according to claim 1 or 2,
An image forming apparatus for forming an image on recording paper;
A paper feeding device or a paper delivery device connected to the image forming apparatus,
The control unit of the image forming apparatus includes the master communication node,
The image forming system, wherein a control unit of the paper feeding device or the paper discharging device includes the slave communication node.
Broadcast communication method for performing broadcast communication between the master communication node and the plurality of slave communication nodes via a common bus through which a synchronization clock for data transmission is constantly transmitted from the master communication node to the plurality of slave communication nodes In
A command transmission step of transmitting command data with data indicating broadcast communication from the master communication node to the plurality of slave communication nodes via the common bus;
In each of the plurality of slave communication nodes, the received command data is analyzed, and when the command data is normally received, it is normally received in the confirmation response display unit of the status data for confirmation response to the master communication node. A setting step for setting to display, and
And a status transmission step of transmitting the set status data from the plurality of slave communication nodes to the master communication node via the common bus in synchronization with the synchronization clock. . 9. The method of claim 8, wherein
After the status sending step,
In the master communication node, a determination step of analyzing the confirmation response display unit of each received status data and determining whether there is a slave communication node that has not made a normal response according to the setting of the display unit, and,
A method comprising: a command retransmission step of transmitting the command data with ID information unique to the node from the master communication node to a slave communication node that has not made a normal response via the common bus. The method of claim 8 or 9, wherein
Transmission of the command data from the master communication node to the plurality of slave communication nodes is performed by command data transmission means included in the common bus, and transmission of the status data from the plurality of slave communication nodes to the master communication node. Is performed by status data transmission means included in the common bus. The method of claim 8 or 9, wherein
Transmission of the command data from the master communication node to the plurality of slave communication nodes and transmission of the status data from the plurality of slave communication nodes to the master communication node are performed by common data transmission means included in the common bus. A method characterized by the above.

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