KR101743048B1 - Integrated broadcasting system using CAN communication - Google Patents

Abstract

The present invention relates to an integrated broadcasting system. More particularly, to an integrated broadcasting system using CAN communication capable of real-time monitoring by detecting a transmission / reception occurring on a bus by a plurality of nodes, and reducing the load and error probability on the bus of the CAN.
To this end, the present invention provides an integrated broadcasting system using a CAN communication including a plurality of broadcasting devices including a compression / decompression unit, a communication unit, and a check device including a display module.

Description

Integrated broadcasting system using CAN communication {omitted}

The present invention relates to an integrated broadcasting system. More particularly, to an integrated broadcasting system using CAN communication capable of real-time monitoring by detecting a transmission / reception occurring on a bus by a plurality of nodes, and reducing the load and error probability on the bus of the CAN.

[0002] Recently, as a communication device and a control device technology have greatly developed, a digital integrated broadcasting system in which various data information is exchanged in real time has been established.

Integrated broadcasting system means a device or system for limiting broadcasting to a specific area or building in order to minimize damages due to high-rise buildings, residential complex buildings and personal privacy.

This integrated broadcasting system is referred to as a digital integrated broadcasting system when digitalized by control means for controlling a plurality of distributed target terminals and communication means for exchanging data between target devices.

The digital integrated broadcasting system includes not only a central broadcasting control device which integrally and organically processes the whole process of broadcasting but also various input devices for conducting a complex broadcasting, a device for supplying power to a plurality of devices constituting a broadcasting system A plurality of receivers for ultimately receiving and broadcasting a signal distributed to each of a plurality of divided spaces such as a power supply, a power supply, a household, a gymnasium, an audiovisual room, a music room, An apparatus, and a signal distribution apparatus for decomposing signals into these reception apparatuses.

In such an integrated type broadcast system, a plurality of devices or devices constitute an integrated system for broadcasting, and it is very important that a plurality of devices and devices constituting the devices are organically constituted.

Meanwhile, CAN (Controller Area Network) was originally developed as a network protocol for automobile, and it has excellent performance and low cost, and has been designated by ISO as an international standard for serial communication protocol ISO11898, so that application to other industrial fields is actively applied have. In particular, CAN's high data throughput, robust immunity to electrical disturbances, and the ability to detect and correct errors are known to be widely used not only in automobiles, but also in a variety of industries including manufacturing, aviation and railways.

The CAN communication protocol defines the information exchange method between communication terminals defined according to the OSI reference model. Among the seven layers of OSI, CAN architecture is defined over the lower physical layer and the data link control layer. Since CAN prevents collision of messages by an identifier indicating priority, a priority message can use a bus (BUS) without delay time, and is suitable for real-time data transmission.

An example of the CAN communication method having such advantages is applied to a digital integrated broadcasting system is not yet common.

The reason for this is as follows.

First, priority is given according to the ID assigned in communication between devices using the CAN bus. In case of message collision, a message having an ID with a higher priority is transmitted first, and a message having a lower ID is transmitted. There is a possibility that an average transmission delay occurs and collision between messages occurs.

Second, when a large number of broadcast-related devices are connected by CAN communication and transmit / receive a large amount of data, since the data transmission amount increases, the load and error probability of the CAN bus increases.

Third, when displaying the received data list on the screen in order to monitor the transmission / reception data of each broadcasting related device, the received data is stored in the memory, and data is added to the list output component every predetermined time to output the received data list. The time taken to store the received data in the memory is constant regardless of the amount of data, but the more time the list is stored in the display module, the longer it takes to add a new list.

Prior Art Document: KR Patent Registration No. 1152225 (registered May 25, 2012)

It is an object of the present invention to provide an integrated broadcasting system using CAN communication so that CAN communication can be smoothly applied to a broadcasting system.

In order to achieve the above object, the integrated broadcasting system using the CAN communication according to the present invention is a device 1, 2, 3, ..., n (n is a finite natural number) And the devices 1 to n regard the 64-bit data field as 8 signals each having 8 bits, and calculate the DLC (Data Length Code) of the compressed data. If the DLC of the compressed data is smaller than the DLC of the uncompressed data, the compressed data is transmitted. If the DLC of the compressed data is equal to or larger than the DLC of the uncompressed data, the uncompressed data is transmitted. A compression and decompression unit for checking the DLC of each message ID and determining whether the transmitted CAN frame is compressed; And a second node connected to the CAN bus cable and connected to the first transceiver for performing data transmission and reception and a second node connected to the CAN bus cable for performing data transmission and reception, (Rx) data from the second node when transmitting the compressed data or the uncompressed data at the first node (Tx), and checking the current transmission / reception status in real time to detect an error.

In addition, in order to prevent an increase in the time taken to add a new list as the number of lists stored in advance in a list component composed of a header, a list box, and a scroll bar increases, the present invention stores data received in a memory (K is a finite number of natural numbers), and if the number of received data exceeds k, the data is stored only in the memory, and the scroll bar The range can be changed by the number of received data, so that when the user moves the scroll bar, the data is read from the memory according to the position of the scroll bar, and the new data is outputted when the screen is updated And a list display module, and the devices 1 to n The results can include checking devices to perform real-time checks.

According to the present invention, since compression and decompression are performed through transmission data compression region setting, it is not necessary to set a maximum change amount range for storing the change amount, and it is determined whether or not the compression is performed by the size of the DLC. There is no need to have an effect.

In addition, according to the present invention, there is an effect that real-time monitoring can be performed by detecting a transmission / reception occurring on the bus in a manner that a plurality of nodes are provided and the first node performs basic communication and feeds back the second node on the bus.

According to the present invention, even if the user changes the output range by using the scroll bar when checking communication between broadcasting devices, only 20 to 30 lists to be outputted on the screen are taken out from the memory and outputted to the screen, There is an effect that does not occur.

1 is a configuration diagram of a unified broadcasting system using CAN communication according to a preferred embodiment of the present invention;
Fig. 2 is a conceptual diagram showing a specific configuration of the communication unit in Fig. 1. Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the preferred embodiments of the present invention will be described below, but it is needless to say that the technical idea of the present invention is not limited thereto and can be variously modified by those skilled in the art.

FIG. 1 is a configuration diagram of an integrated broadcasting system using CAN communication according to a preferred embodiment of the present invention, and FIG. 2 is a conceptual diagram illustrating a specific configuration of a communication unit in FIG.

Referring to FIG. 1 and FIG. 2, in configuring CAN communication between broadcasting apparatuses of the integrated broadcasting system in which mutual data exchange and communication are to be performed, each of the apparatuses 100, 200, 3, and the device n (n is a finite natural number) include compression and decompression units 110, 210 and 510 and communication units 120, 220 and 520, respectively. In addition, the integrated broadcasting system using CAN communication according to the present invention further includes a check device 600 connected to the devices 1 to n to perform a real-time check.

The compression / decompression units 110, 210 and 510 determine whether or not the data is compressed according to the DLC (Data Length Code), compress the transmission data and restore the reception data using the transmission data compression region setting and the header.

Standard CAN 2.0A uses an 11-bit identifier, and 2.0B uses an 11-bit or 29-bit identifier. A standard CAN data frame with an 11-bit identifier can be divided into a total of 7 bit segments, and a data field consists of 0 to 8 bytes including data to be transmitted from one node to another. The data field is preceded by a control field, and a portion of the control field is filled with a 4-bit DLC.

The data field has a maximum length of 64 bits, which is different in length according to the ID and includes the largest number of bits in the CAN frame, and thus can be compressed most efficiently.

 Since the data transmission period in the CAN node is very short considering the broadcast time, the amount of change between the previous data frame and the current data frame is not large. Therefore, if only the amount of change between the previous frame and the current frame is transmitted, the CAN message data length can be greatly reduced.

When the number of signals is large in the data compression, that is, when the number of IDs is large and the bit size of each signal is irregular, more processing time is required. When the header is used, the number of bits of the header is increased according to the number of signals, The head is increased.

The compression and decompression units 110, 210, and 510 regard the 64-bit data field as 8 signals each having 8 bits to calculate the DLC of the compressed data.

If the DLC of the compressed data is smaller than the DLC of the data before compression, the compressed data is transmitted. On the other hand, if the DLC of the compressed data is equal to or greater than the DLC of the uncompressed data, the uncompressed data is transmitted.

The receiving side checks the DLC of each predefined message ID to determine whether the transmitted CAN frame is compressed. Therefore, it is not necessary to judge whether the two IDs are compressed as in the conventional method, and the efficiency is improved.

The compression / decompression units 110, 210 and 510 set compression areas of data to be transmitted for compression.

The CAN message compression (transmitting side) of the compression and decompression units 110, 210 and 510 is performed by the following procedure.

First, it is checked whether the compression target message to be transmitted is the initial message. If the message is the first message, the data is directly transmitted without compression (because there is no change). Otherwise, the compression area setting algorithm is used to set the data compression area. A specific compression region setting algorithm is not described here, and a general compression region setting algorithm can be used.

After setting the data compression area, the memory map is determined and the DLC is calculated.

As a result of the calculation, DLC of the data before compression> DLC of the compressed data transmits the compressed data, and when the DLC of the data before compression is DLC of the compressed data, the data before the compression is transmitted.

The restoration (reception side) of the CAN message of the compression and decompression units 110, 210 and 510 is performed by the following procedure.

If the received message is not the first message, the DLC of the received data is less than the predefined DLC. If the received message is not the first message, And restores the data change amount using the area setting algorithm.

When the data change is restored, the current signal value is calculated as follows.

Current signal value = previous signal value + variation

Since the compression and decompression units 110, 210, and 510 perform compression and decompression through the DLC and transmission data compression region setting, it is not necessary to set the maximum variation amount range for storing the variation amount. Therefore, it is not necessary to judge whether the two IDs are compressed or not.

The communication units 120, 220, and 520 use a plurality of nodes for each device to feed back the data transmitted from the first node to the second node, so that error detection is possible immediately.

2, the communication units 120, 220, 320 and 420 of the devices 1 to n are connected to a first transceiver 126, 226, 326, and 426 connected to a CAN bus cable to perform data transmission / And a second node connected to the CAN bus cable and connected to a second transceiver for conducting data transmission and reception, a second node, and a second node connected to the CAN bus cable, 324, and 424, respectively.

(Tx) from the first node 122, 222, 322, 422 via the second and third nodes 124, 224, 324, 424 (Rx) to check the current transmission / reception status in real time so that an error can be detected.

The CAN is given priority according to the assigned ID, and the message having the ID having the higher priority is transmitted first when the message collision occurs, and the message having the lower ID is stopped. Generally, an average transmission delay occurs when traffic increases in CAN.

In the integrated broadcasting system, when the devices 1 ~ n connected to the CAN bus have one node, the priority is determined according to each ID and the message is transmitted. If an average transmission delay occurs due to an increase in traffic, a message collision may occur on the network.

Each of the communication units 120, 220, 320 and 420 performs basic communication with the first node 122, 222, 322 and 422 and feeds back the second node 124, 224, 324 and 424 on the bus Real-time monitoring is possible by detecting transmission and reception on the bus.

That is, when the feedback reception state of the second node 124, 224, 324, and 424 is compared with the existing data, it is determined that the data is transmitted without any abnormality. Otherwise, it is determined that an error has occurred and retransmission or reset Can be performed.

The check device 600 is connected to the devices 1 to n to perform a real-time check.

It is necessary to accurately check a large amount of data in a short time in order to quickly detect and display an error occurrence in a situation where a plurality of broadcasting apparatuses perform mutual CAN communication.

In the case of a general monitoring system, there is no big problem in displaying data in real time when the capacity is small as in the past vehicle data. However, when a large capacity is transmitted as in the case of the integrated broadcasting system, it takes a long processing time and is not suitable for use in the field. In particular, when displaying data in real time, it is necessary to process received data and display the data at a predetermined period of time. However, there is a problem that the longer the data is accumulated, the longer the cycle becomes.

As a display method of the check device, there are a method of displaying a string in a list, a method of displaying a time in a horizontal axis and a data value in a vertical axis.

The list method stores the received data in memory and adds data to the list output component at regular intervals. The time taken to store the received data in the memory is constant regardless of the amount of data, but the longer it takes to add a new list to the list output component, the longer the number of lists stored in the display module.

The display module 610 of the present invention is limited to the number (for example, 30) that can be displayed on one screen when the list is added to the list output component in order to prevent the list addition time from becoming longer as the number of lists stored in advance increases.

The display module 610 displays the data received when the check is started, in order to prevent a longer time for adding a new list as the number of lists stored in advance in a list component composed of a header, a list box and a scroll bar increases (K is a finite number of natural numbers), which is a number that can be displayed and displayed on one screen in the list component.

If the number of received data exceeds k, it stores data only in memory and allows the range of scroll bar to be changed by the number of received data without adding list. When the user moves the scroll bar, the data is read from the memory according to the position of the scroll bar, and the data is changed to the previously added list to output new data when the screen is updated.

For example, since there is no need to add or delete a list in the state in which the first 30 lists are added to the list, the performance problem is solved, and the number of displayable data becomes equal to the number of data that can be stored in the memory.

According to the display module 610, even if the user changes the output range by using the scroll bar, only 20 to 30 lists to be displayed on the screen are taken from the memory and displayed on the screen So that no interruption or delay occurs.

Although not shown, each of the devices 1 to n may further include an identification unit, a restoration unit, and a detection unit.

The confirmation unit goes beyond simply notifying the occurrence of an error, and provides the upper layer with detailed information of the error that has occurred. That is, the verification unit provides detailed information on the upper layer with respect to the types of errors as well as the bit error detection and the frame unit error detection.

CAN faults include physical errors in bus cables and frame errors caused by physical errors in the logical layer.

Bus cable faults include CAN_H, CAN_L disconnect, CAN_H, VCC short of CAN_L, CAN_H, GND short of CAN_L, CAN_H and CAN_L short, CAN_H and CAN_L short of the same location,

A frame error is a Bit Error that occurs when the bit level is different by monitoring a signal level to be transmitted, a Stuff Error that occurs when the bit stream having the same signal level is longer than a predetermined bit, a CRC Delimiter, an ACK Delimiter , End of Frame and Intermission part have a fixed format. Form error occurs when there is an error in the value of this part. Controller transmitting CAN message transmits a recessive level signal to ACK slot and transmits this message normally All nodes are required to transmit a signal of dominant level to the ACK slot. The ACK error occurs when the node that transmitted the CAN message receives the message and the signal of the ACK slot is not at the dominant level.

On the other hand, if an error occurs in the CAN bus cable or module, the transmission error counter of the CAN module increases and becomes a bus off state when it becomes a specific counter (256, for example). This prevents situations where other nodes that are not normal can not use the CAN bus due to CAN error of one node. The restoration unit provides an automatic restoration function to prevent the bus from being kept in a state where the error is resolved even in a situation where the error is resolved. For example, if the ABO (Auto Bus On) bit is set to 1, 128 × 11 recessive (1) bits are received in the bus off state, and then the bus is turned on again.

The detection unit detects the activation state of each node connected to the CAN bus, identifies the node where the communication function of the CAN bus is interrupted, and corrects the control logic or interrupts the system according to the interrupted update information.

Devices 1 to n correspond to each individual broadcasting apparatus.

The devices 1 to n include a sound source device for generating a sound source signal, a digital audio mixer for receiving a sound source signal from the sound source device, checking the volume value of the sound source, adjusting the volume and tone, An audio input unit electrically connected to the mixer, a sound source equipment connection terminal electrically connected to the sound source equipment, an Ethernet connection terminal allowing the setup and operation of the entire system through the network, a sound source signal input through the audio input unit, , A digital master controller including an audio output terminal, an audio input section for receiving a sound source signal output from the digital master controller, an audio input section for receiving a sound source signal input through the audio input section, An audio matrix IC for outputting audio signals on a channel combination of an audio matrix A main control IC for controlling the operation of the audio matrix IC and the digital amplifier section according to the set value and analyzing the operation state, a power amplifier for receiving the sound source signal outputted from the digital master controller, A digital matrix amplifier with a built-in power amplifier to amplify, and a digital master controller and a system PC connected via a wired or wireless network to monitor and control the overall system operation, including digital audio mixers and digital matrix amplifiers .

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100, 200, 300, 400, 500 - Devices 1 to n
110, 210, 510 - The compression and decompression unit
120, 220, 320, 420, 520 -
122, 222, 322, 422 - a first node
124, 224, 324, 424 - the second node
126, 226, 326, 426 - a first transmitter
128, 228, 328, 428 - a second transmitter
600 - Check device
610 - Display module

Claims (4)

Data communication between apparatuses 1, 2, 3, ..., n (n is a finite natural number), which is each individual broadcasting apparatus constituting the integrated broadcasting system, is performed by a CAN (Controller Area Network) silver
The DLC (Data Length Code) of the compressed data is calculated by considering the 64-bit data field as eight signals each having 8 bits, and when the DLC of the compressed data is smaller than the DLC of the data before compression, When the DLC of the compressed data is equal to or greater than the DLC of the data before compression, the pre-compression data is transmitted. On the receiving side, the DLC of each predefined message ID is checked to determine whether or not the transmitted CAN frame is compressed And a restoration unit; And
A first node connected to a CAN bus cable and connected to a first transceiver for performing data transmission and reception, and a second node connected to a CAN transceiver connected to the CAN bus cable for performing data transmission and reception, (Rx) from the second node when the compressed data or the uncompressed data is transmitted (Tx) from the first node to check the current transmission / reception status in real time to detect an error
Lt; / RTI >
In order to prevent a longer time for adding a new list to a list component as the number of lists stored in a list component composed of a header, a list box, and a scroll bar increases,
When the check is started, the received data is stored in the memory, and only a list k (k is a finite natural number) number that can be displayed on the screen in the list component is added. If the number of received data exceeds k, So that the range of the scroll bar can be changed by the number of received data without adding a list to the list component,
And a list display module for reading data from the memory according to the position of the scroll bar when the user moves the scroll bar, and outputting new data when the screen is updated by changing the data to the added list,
A check device connected to the devices 1 to n for performing a real-time check
/ RTI >
Each of the devices 1 to n further includes an identification unit, a restoration unit, and a detection unit,
The verification unit provides detailed information to the upper layer for bit error detection, frame unit error detection and error type, including CAN_H, CAN_L line disconnection, CAN_H, VCC short of CAN_L line, CAN_H, CAN_L line Provides information on frame errors including GND short, CAN_H line and CAN_L line short, CAN_H line and CAN_L line disconnection, network cable termination including network loss, Bit Error, Stuff Error, Form Error and ACK Error ,
When the ABO (Auto Bus On) bit is set to 1 to prevent the CAN bus cable or module from failing due to a fault in the CAN bus cable or module, It provides automatic restoration function to receive 11 recessive (1) bits and then turn on the bus on state,
The detection unit detects the activation state of each node connected to the CAN bus, identifies the node where the communication function of the CAN bus is interrupted, corrects the control logic according to the information whose update has been stopped, or stops the system. system. delete The method according to claim 1,
At least one of the devices 1 to n includes a digital matrix amplifier. The method according to claim 1,
At least one of the devices 1 to n includes a digital master controller.

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