JP2005318191A - Master/slave synchronous communication system using ieee1394 network and automatic allocating method for synchronous communication resource - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a master 1 and all slaves 2n connected on an IEEE1394 network 3 to send and receive control data within a control cycle which is an integral multiple of an isochronous cycle by automatically and effectively allocating synchronous communication resources. <P>SOLUTION: The master 1 inputs the control cycle which is the integral multiple of the isochronous cycle, detects slaves 2n connected on the IEEE1394 network, and equally allocates use bandwidths of respective isochronous cycles. Further, the master 1 automatically acquires/allocates synchronous communication resources from an IRM, generates a synchronous communication management table 14 for communication between the master 1 and slaves 2n, and reports the synchronous communication resource table 14 to the slaves, so that the master 1 and slaves 2n communicate with each other according to the synchronous communication management table 14 and synchronous communication resource data 2n31. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a master-slave synchronous communication system and an automatic allocation method of synchronous communication resources using an IEEE 1394 network.

In the isochronous transfer of the conventional IEEE 1394 communication system, the device that performs the isochronous transfer acquires the bandwidth and channel from the isochronous resource manager (hereinafter referred to as IRM) in advance, and receives the cycle start packet, and acquires the right to use the bus. The acquired device sends data. During the isochronous transfer period, each communication device acquires the right to use the bus in order and transmits data (for example, see Non-Patent Document 1).
Normally, all communication devices are configured to transfer data during the isochronous transfer period. If you want to add a new device but the remaining bandwidth is less than the bandwidth you want to acquire, you can adjust one device by adjusting the bandwidth. If the amount of data is reduced or the amount of data cannot be reduced, a new device cannot be added.

In order to deal with such a problem, a technique is disclosed in which as many isochronous transfers as possible can be started by transferring data of devices having variable transfer cycles for several cycles at a time. This will be described with reference to FIG.
In FIG. 18, when data A92, data B93, and data C94 are isochronously transferred as shown in FIG. 18A, even if data D95 is newly transferred, the remaining bandwidth 97 of the isochronous transfer period transfers data D95. If the bandwidth is smaller than the data D bandwidth 96 necessary for this, as shown in (b), three data A92 are transferred together as one packet in the first cycle, and data D95 is transferred in the remaining bandwidth. In the second cycle, three data B93s are combined and transferred as one packet, and data D95 is transferred in the remaining bandwidth. In the third cycle, three data C94s were combined and transferred as one packet, and data D95 was transferred in the remaining bandwidth, so that the isochronous transfer period was effectively utilized as much as possible. (See Patent Document 1)
Japanese Patent Laying-Open No. 2003-229857 (FIG. 1) IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus

However, in the isochronous transfer of IEEE 1394 communication described in Non-Patent Document 1, the amount of data that can be transmitted in one isochronous cycle is determined. Therefore, when the number of connected devices increases, the bandwidth for isochronous transfer cannot be secured. However, there is a problem that data for one device is reduced or data cannot be transmitted.
The IRM also includes a BANDWIDTH # AVAILABLE register and a CHANNELS # AVAILABLE register defined in the IEEE 1394 standard. Bandwidth and channel synchronous communication resources are managed by the IRM BANDWIDTH # AVAILABLE and CHANNELS # AVAILABLE registers. In other words, because synchronous communication resources are managed in units of isochronous cycles, even if the control cycle is longer than the isochronous cycle, the same command data is transmitted for each isochronous cycle or the data is divided and transmitted. There was also a problem that the communication load increased and wasted.

In Patent Document 1, a special device with a variable transfer cycle for transferring data for several cycles at a time is required. Even when data is collected, data for each isochronous cycle is required. When the control cycle is longer than the isochronous cycle, there is a problem that the synchronous communication resource cannot be effectively used.

The present invention has been made in view of such problems, and one station master and one or more slaves exchange control data in a control cycle that is an integral multiple of a preset isochronous cycle. It is an object of the present invention to provide a master / slave synchronous communication system and a method for automatically allocating synchronous communication resources.

In order to solve the above problem, the present invention is as follows.
The invention described in claim 1
In a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle.
The master
Means for acquiring control cycle data in which the control cycle is set;
Means for detecting the number of slaves connected on the IEEE 1394 network;
Means for allocating the slaves to isochronous cycles for the control period according to the control period data and the detected number of slaves;
Means for acquiring a bandwidth and a channel, which is a synchronous communication resource for exchanging the communication data with the slave assigned to the isochronous cycle, from an isochronous resource manager (hereinafter referred to as IRM);
Means for creating a synchronous communication management table that includes the correspondence between the acquired synchronous communication resource and the slave and the allocation information to the isochronous cycle;
Means for notifying the slave of information of the associated synchronous communication resource;
Means for performing isochronous communication according to the synchronous communication management table,
The slave is
Means for receiving information of the synchronous communication resource from the master;
Means for performing isochronous communication based on information of the synchronous communication resource;
Means for transmitting response data to the command data from the master.

The invention described in claim 2
A master of a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle. In the automatic allocation method of synchronous communication resources in
Obtaining control cycle data in which the control cycle is set;
Detecting the number of slaves connected on the IEEE 1394 network;
Allocating the slaves so that the number of slaves is equal to isochronous cycles corresponding to the control period, based on the control period data and the detected number of slaves;
Obtaining a bandwidth and a channel, which are synchronous communication resources for exchanging the communication data with the slave assigned to the isochronous cycle, from an IRM;
Creating a synchronous communication management table that includes the acquired synchronous communication resources and the correspondence between the slaves and the allocation information to the isochronous cycle;
Notifying the slave of information of the associated synchronous communication resource;
It is characterized by comprising.

The invention described in claim 3
The master / slave synchronous communication system according to claim 1,
The master or the slave or each of the master and the slave comprises means having a data amount of the communication data,
The master includes means for calculating or reading out the communication data amount for each slave.

The invention according to claim 4
A master of a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle. In the automatic allocation method of synchronous communication resources in
Obtaining control cycle data in which the control cycle is set;
Detecting the number of slaves connected on the IEEE 1394 network;
Calculating or reading the amount of communication data of all the slaves for each slave from the master or the slave or the master and the slave; and
Allocating the slaves to isochronous cycles such that the bandwidth used in each isochronous cycle is equal;
Obtaining a bandwidth and a channel, which are synchronous communication resources for exchanging the communication data with the slave assigned to the isochronous cycle, from the IRM;
Creating a synchronous communication management table that includes the acquired synchronous communication resources and the correspondence between the slaves and allocation information to the isochronous cycle;
Notifying the slave of information of the associated synchronous communication resource;
It is characterized by comprising.

The invention described in claim 5
The master / slave synchronous communication system according to claim 1,
The slave includes a synchronous communication resource acquisition prohibition flag for selecting allocation of synchronous communication resources by the master.

According to the first aspect of the present invention, in a master / slave synchronous communication system in which one master and one or more slaves are connected to the IEEE 1394 network, an isochronous cycle unique to IEEE 1394 can be performed without any special setting. Control data can be exchanged in synchronization with an integer multiple of the control cycle.

According to the second aspect of the present invention, the communication load is evenly distributed, the synchronous communication resource can be automatically acquired and allocated, and the synchronous communication resource can be used efficiently. That can be used freely by other devices and systems, and that can be used in combination with devices and systems that communicate other data via synchronous communication, or that use the remaining time of isochronous communication to perform asynchronous transfer. It is effective for construction.

According to the third aspect of the present invention, in a master / slave synchronous communication system in which devices having different amounts of data to be exchanged between the master and each slave are connected on the IEEE 1394 network, the control is an integral multiple of the isochronous cycle unique to IEEE 1394. Data unique to each slave necessary for allocation of synchronous communication resources for sending and receiving control data in synchronization with the period can be reliably acquired.

According to the fourth aspect of the present invention, in a master / slave synchronous communication system in which devices having different amounts of data exchanged between the master and each slave are connected on the IEEE 1394 network, the communication load is evenly distributed and synchronized. Communication resources can be automatically acquired and allocated, and synchronous communication resources can be used efficiently, so other devices and systems can freely use surplus resources, and other data can be synchronized. It is effective for the construction of a system that performs asynchronous transfer by using a mixture of devices and systems that communicate and the remaining time of executing isochronous communication.

According to the fifth aspect of the present invention, in addition to the effects of the first and third aspects, the slave device can be used as a general IEEE 1394 device.

Hereinafter, specific examples of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a master-slave synchronous communication system using an IEEE 1394 network embodying the present invention. In the figure, 1 is a master, 2i (i = 1, 2,... N) is a slave, and 3 is an IEEE 1394 network.
In the master 1, from the control cycle data 11 in which a value that is an integral multiple of the isochronous cycle and the number of connected slaves 121 representing the number of slaves detected by the slave detection unit 12, the slave allocating unit 13 The slave 2i detected in the cycle is allocated, and the synchronous communication management table 14 is created.
The synchronous communication resource acquisition / allocation unit 18 calculates necessary synchronous communication resources from the synchronous communication management table 14, requests the IRM, acquires the resources, and allocates the acquired resources to the master 1 and the slave 2i. In the synchronous communication management table 14, the acquired synchronous communication resource is also managed.
When the cycle start packet reception processing unit 15 receives the cycle start packet, the command data transmission unit 16 transmits the command data 161 and the response data reception unit 17 receives the response data 171 according to the synchronous communication management table 14. On the other hand, in the slave 2i, when the synchronous communication processing unit 2i3 receives the command data 2i11 in the command data receiving unit 2i1 using the synchronous communication resource data 2i31 assigned from the master 1, the response data transmitting unit 2i2 receives the response data 2i21. Send. As described above, the master and all slaves can exchange control data within a control cycle that is an integral multiple of the isochronous cycle.

The control cycle data 11 is data representing the control cycle of the master / slave synchronous communication system, and is set to an integer multiple of an isochronous cycle defined by the IEEE 1394 standard.
The cycle start packet is a packet indicating the start of an isochronous cycle defined in the IEEE 1394 standard.

FIG. 2 is a detailed view of the synchronous communication management table 14 of FIG. The synchronous communication management table 14 includes the number of isochronous cycles corresponding to the set control cycle data 11, the number of communication slaves representing the number of slaves communicating in each cycle, and the commands exchanged between the master and the slaves assigned in the cycle. And a total of bandwidths for response data, a communication slave number indicating an address for communication, a bandwidth used for communication, and an array of channels. The arrangement of communication slave numbers is secured by the number of detected slaves. As an embodiment of the invention of claim 1, data is shown in which the control cycle is 500 μs, the number of slaves is 8 stations, and the command and response data bandwidth between the master and each slave is 500 bandwidth allocation units.

FIG. 3 is a detailed view of the synchronous communication resource data 2131 corresponding to the slave 21 in the synchronous communication resource data 2i31 of FIG. The synchronous communication resource data 2131 is composed of respective bandwidths and channels used for synchronous communication of command and response data. As an embodiment of the invention of claim 1, the command data bandwidth between the master 1 and the slave 21 is 500 bandwidth allocation units, the channel is channel number 0 (ch0), and the response data between the master 1 and the slave 21 The data is shown in the case where the bandwidth is 500 bandwidth allocation units and the channel is ch1.

FIG. 4 is a communication timing chart according to the first embodiment of the present invention. 2 operates according to the synchronous communication resource data of FIG. 3 implemented in each slave, the number of communication slaves in cycle # 1 of the synchronous communication management table 14 when the master receiving the cycle start packet of cycle # 1 operates. The command data Ci (i = 1, 5) is transmitted to the communication slave number. When the slave receives the command data, it transmits response data Ri (i = 1, 5). Next, the master that has received the cycle start packet of cycle # 2 transmits command data Ci (i = 2, 6) to the number of communication slaves and the communication slave number of cycle # 2 in the synchronous communication management table 14. When the slave receives the command data, it transmits response data Ri (i = 2, 6). Similarly, in cycle # 3, command data Ci (i = 3, 7) and response data Ri (i = 3, 7) are transmitted, and in cycle # 4, command data Ci (i = 4, 8). Response data Ri (i = 4, 8) is transmitted.

As described above, communication data is exchanged between the master and the slaves # 1 and # 5 in the first 125 μs, and the master and the slaves # 2 and # 6 between 125 and 250 μs, and the master and the slave # between 250 and 375 μs. 3, # 7 can transmit and receive communication data between master and slave # 4 and # 8 between 375 and 500 μs, and the master transmits and receives communication data with all slaves # 1 to # 8 within a control period of 500 μs. be able to. Thereafter, by repeating the same processing for each control cycle, one master station and eight slave stations can be operated in synchronization with a control cycle of 500 μs. Further, by evenly assigning the number of slaves to each cycle, transmission / reception of communication data can be completed within a 2000 bandwidth allocation unit in each cycle.

In this way, the master can exchange communication data with all slaves within a control cycle that is an integral multiple of the set isochronous cycle, and the master and slave can operate in synchronization with the control cycle. Also, by equalizing the bandwidth used for each isochronous cycle, synchronous communication resources can be used efficiently, and other devices and systems can use the remaining resources freely, and other data can be used. Asynchronous transfer can be performed by using a mixture of devices and systems communicating by synchronous communication, and also using the remaining time of executing isochronous communication.

FIG. 5 is a diagram showing the minimum format format of the configuration ROM possessed by the IEEE 1394 equipment, and includes a vendor ID called 24-bit vendor_id representing vendor-specific information.

FIG. 6 is a diagram illustrating a general format format of a configuration ROM included in the IEEE 1394 equipment, and FIG. 7 is a diagram illustrating a format of a bus_info_block included in FIG. 5 includes a vendor ID (node_vendor_id) similar to that in FIG. 5 and a 40-bit chip ID obtained by concatenating an 8-bit chip_id_hi and a 32-bit chip_id_lo that make a device unique within the vendor. The 64-bit information combining the vendor ID and the chip ID is called EUI-64 (Extended Unique Identifier, extended unique identifier, 64 bits), and is information that can be uniquely identified in all IEEE 1394 devices.

FIG. 8 is a diagram showing the format of CHANNELS_AVAILABLE for managing an isochronous channel that is one of the synchronous communication resources of the IRM. A total of 64 bits of channels_available_hi and channels_available_lo of 32 bits correspond to the isochronous channel number. Channels_available_hi is assigned in order from bit 0 to channel number 0, bit 31 is assigned to channel number 31 in order, bits 0 to channels_available_lo are assigned in order from channel number 32, and bit 31 is assigned to channel 63. The value of each bit indicates the usage status of the corresponding channel. If 0, the channel is already owned and cannot be used, and 1 indicates that the channel is usable. In order to acquire the channel ownership, the channel is acquired according to the prescribed procedure described in Non-Patent Document 1.

FIG. 9 is a diagram showing a BANDWIDTH_AVAILABLE format for managing an isochronous bandwidth that is one of the synchronous communication resources of the IRM. 13-bit bw_remaing represents the amount of isochronous bandwidth that can be used for the current allocation. This amount of bandwidth is represented by a time called a bandwidth allocation unit, where one unit is approximately 20 ns, the time required to transmit one quadlet data at a data rate of 1600 Mbps. The initial value of bw_remaining, that is, the amount of bandwidth corresponding to 100 μs in the isochronous transfer period is 4951 bandwidth allocation units. In order to acquire the bandwidth allocation, the bandwidth is acquired according to the prescribed procedure described in Non-Patent Document 1.

FIG. 10 is a flowchart showing a processing procedure of the automatic allocation method for synchronous communication resources in the master / slave synchronous communication system according to claim 2 of the present invention. The synchronous communication resource automatic allocation method according to claim 2 will be described step by step with reference to FIG.
First, in step S010, control cycle data 11 having a control cycle set in advance is taken out. In step S020, the number of slaves 121 connected on the network using the function of the IEEE 1394 standard described in Non-Patent Document 1 is calculated. The communication slave number for communication by the master is detected. At this time, the vendor ID of FIG. 5 or the information of EUI-64 of FIG. Next, based on the control cycle data 11 acquired in S030 and the detected number of slaves 121, the area of the synchronous communication management table 14 is secured and the internal data is cleared to zero. In S040, the number of cycles calculated by equation (1) is set in the synchronous communication management table 14.
Number of cycles = control period [μs] ÷ 125 [μs] (1)

In S050, the data area of the first cycle of the synchronous communication management table 14 is acquired. In S060, the communication slave number and the command / response bandwidth are stored in the synchronous communication management table 14. The bandwidth is calculated from equation (2).
Bandwidth = Header + Communication data size [byte] / 4 + Data communication gap (2)
As described in Non-Patent Document 1, the header size and data communication gap are defined in the IEEE 1394 standard.

In S070, 1 is added to the number of communication slaves in the synchronous communication management table 14. In S080, it is checked whether or not the next cycle number exceeds the number of cycles. If not, the data area of the next cycle is acquired in S090. If it exceeds, the data area of the first cycle is acquired in S100. The processing from S060 to S100 is repeated for all the slaves. In S110, the sum of the command / response bandwidths assigned to each cycle in each cycle is calculated. In S120, the maximum value of the bandwidths in each cycle is obtained. In S130, the maximum bandwidth is obtained from the IRM. To obtain the channel number used for command / response data communication with the slave. In S140, it is checked whether or not the synchronous communication resource can be acquired. If acquired, the synchronous communication resource data is stored in the synchronous communication management table 14 in S150, and the synchronous communication resource information corresponding to each slave is notified in S160. If synchronous communication resource acquisition has failed, error processing is performed in S170 and the process ends. As described above, the synchronous communication management table 14 of FIG. 2 and the synchronous communication resource data 2i31 including FIG. It is possible to automatically acquire and allocate synchronous communication resources for this purpose.

An embodiment of the invention described in claim 3 will be described. In addition to the master / slave synchronous communication system according to claim 1, the master / slave or the master / slave has a data amount of communication data to be transmitted / received, and the master calculates or reads the data amount for each slave. Means. If the bandwidth information is in the master, for example, after detecting the slave, the synchronous communication resource acquisition / allocation unit 18 uses the vendor ID used for discrimination of the slave device or the correspondence table between the EUI-64 information and the bandwidth of the communication data. When the bandwidth information is in the slave, for example, it is stored in the synchronous communication resource data 2i31, and the master may read the bandwidth information from the synchronous communication resource data 2i31. And in each of the slaves, bandwidth information may be obtained by combining the above methods.

As an embodiment of the invention described in claim 3, FIG. 11 shows communication slave numbers, command data bandwidths, response data bandwidths of each slave when eight slave stations are connected with different communication data amounts, This is information on the total bandwidth that is the sum of the bandwidths of the command data and the response data.

FIG. 13 is a detailed diagram of the synchronous communication management table 14 when the control cycle is 500 μs and the number of slaves shown in FIG. 11 is connected as an embodiment of the invention described in claim 3.

FIG. 14 is a detailed diagram of the synchronous communication resource data 2131 corresponding to the slave 21 as an embodiment of the invention as set forth in claim 3. 11 and 13, the bandwidth for command data between the master 1 and the slave 21 is 500 bandwidth allocation units, the channel is ch10, the bandwidth for response data between the master 1 and the slave 21 is 500 bandwidth allocation units, Data when the channel is ch11 is shown.

FIG. 15 is a communication timing chart according to an embodiment of claim 3 of the present invention. When the synchronous communication management table of FIG. 13 and the synchronous communication resource data of FIG. The command data Ci (i = 3) is transmitted to the communication slave number. When the slave receives the command data, each slave transmits response data Ri (i = 3). Next, the master that has received the cycle start packet of cycle # 2 transmits command data Ci (i = 5, 4) to the number of communication slaves and the communication slave number of cycle # 2 in the synchronous communication management table 14. When the slave receives the command data, it transmits response data Ri (i = 5, 4). Similarly, in cycle # 3, command data Ci (i = 8, 6) and response data Ri (i = 8, 6) are transmitted. In cycle # 4, command data Ci (i = 1, 2, 7) Response data Ri (i = 1, 2, 7) is transmitted.

As described above, the master and the slave # 3 exchange communication data in the first 125 μs, and the master and the slave # 5 and # 4 between 125 and 250 μs, and the master and the slave # 8 and # 8 between 250 and 375 μs. 6, the master and slaves # 1, # 2, and # 7 can exchange communication data between 375 and 500 μs, and the master exchanges communication data with all slaves # 1 to # 8 within a control period of 500 μs. be able to. Thereafter, by repeating the same processing for each control cycle, one master station and eight slave stations can be operated in synchronization with a control cycle of 500 μs. Further, by assigning the slaves to each cycle evenly in the use bandwidth, it is possible to complete the transmission and reception of communication data within the maximum 3000 bandwidth allocation unit in each cycle.

In this way, the master can exchange communication data with all slaves within a control cycle that is an integral multiple of the set isochronous cycle, and the master and slave can operate in synchronization with the control cycle. Also, by equalizing the bandwidth used for each isochronous cycle, synchronous communication resources can be used efficiently, and other devices and systems can use the remaining resources freely, and other data can be used. Asynchronous transfer can be performed by using a mixture of devices and systems communicating by synchronous communication, and also using the remaining time of executing isochronous communication.

FIG. 16 is a flowchart showing a processing procedure of the automatic allocation method for synchronous communication resources in the master / slave synchronous communication system according to claim 4 of the present invention. Differences from the automatic allocation method for synchronous communication resources according to claim 2 shown in FIG. 10 will be described in order with reference to FIG.
After detecting the slave in S020, the synchronous communication bandwidth between the master and each slave is calculated in S021. When the bandwidth information is in the master, the bandwidth ID is calculated from the vendor ID used to determine the slave device or the EUI-64 information and communication data bandwidth correspondence table. When the bandwidth information is in the slave, the bandwidth information is read from the storage location of the bandwidth information, for example, the synchronous communication resource data 2i31. In the case of each of the master and the slave, the above information is combined to acquire bandwidth information. At this time, if the stored information is the communication data size, it is calculated as a bandwidth allocation unit from Equation (2). Next, the slave information acquired in S022 is sorted in descending order of the sum of the bandwidth of the command data and the bandwidth of the response data. As a result, the slave information data of FIG. 11 is sorted into the data of FIG.

Furthermore, in S50, the process that has acquired the data area of the first cycle of the synchronous communication management table 14 is detected, and the cycle in which the slave bandwidth meter assigned to the cycle of the synchronous communication management table is minimum is detected. It replaces with the process which acquires the cycle data area.
In S060, among the data sorted in descending order of the sum of the command data bandwidth and the response data bandwidth in S022, the largest unused one is stored in the synchronous communication management table 14.
In S070, in addition to the process of adding 1 to the number of communication slaves in the synchronous communication management table 14, the sum of the bandwidth of the command data of the slave added to the bandwidth meter and the bandwidth of the response data is added.
The processes from S050 to S070 are repeated for all the slaves in the order sorted in S022.
The processes of S080, S090, S100, and S110 shown in FIG. 10 are deleted.

Other processing is the same as that of the second aspect. As described above, the synchronous communication management table 14 of FIG. 13 and the synchronous communication resource data 2i31 including FIG. 14 are created, and the master and all slaves exchange control data within a control cycle that is an integral multiple of the isochronous cycle. It is possible to automatically acquire and allocate synchronous communication resources for this purpose.

Note that since channel assignment is possible if the same channel number does not overlap within an isochronous cycle, the maximum number of communication slaves for each isochronous cycle is obtained, and channels for transmission / reception with the maximum number of slaves are acquired. You may assign to each isochronous cycle.

FIG. 17 is a detailed view of the synchronous communication resource data 2131 corresponding to the slave 21 as an embodiment of the invention as set forth in claim 5.
If the synchronous communication resource acquisition prohibition flag of the synchronous communication resource data 2131 is valid, the slave 21 is operated by the master 1 as a device that operates at a control cycle that is an integral multiple of the isochronous cycle according to claims 1 to 4. Assigned.
That is, the master 1 executes a bus reset by enabling the synchronous communication resource acquisition prohibition flag of the synchronous communication resource data 2n31 of all the slaves 2n that perform synchronous communication with a control cycle that is an integral multiple of the isochronous cycle, A method for automatically allocating synchronous communication resources according to claim 3 is executed.

When the synchronous communication resource acquisition prohibition flag is invalid, the slave 2n acquires synchronous communication resources from the IRM in the same way as a normal IEEE 1394 device, and executes communication as a general-purpose IEEE 1394 device.
As a result, the slave 2n can be disconnected from the synchronization system with the master 1 and used as a general-purpose IEEE 1394 device.
The same effect can be obtained by using a hardware switch instead of the synchronous communication resource acquisition prohibition flag.

Although it is not possible to transmit and receive in one isocycle, the master and slave can communicate synchronously with a control cycle that is an integral multiple of the isocycle, and therefore, the present invention can be applied to a motion control system that creates a control command in the master.

Configuration diagram of a synchronous communication system between a master and a slave using an IEEE 1394 network embodying the present invention Detailed view of the synchronous communication management table according to the first and second embodiments of the present invention Detailed view of synchronous communication resource data according to the first and second embodiments of the present invention Communication timing chart according to the first and second embodiments of the present invention The figure showing the format of the minimum form of the configuration ROM which the IEEE1394 equipment has The figure showing the format of the general form of the configuration ROM which the IEEE1394 equipment has The figure showing the format of bus_info_block The figure showing the format of CHANNELS_AVAILABLE The figure showing the format of BANDWIDTH_AVAILABLE The flowchart which shows the process sequence of the automatic allocation method of the synchronous communication resource in the master / slave synchronous communication system of Claim 2 of this invention Slave information data according to the third and fourth embodiments of the present invention Sorted slave information data according to the third and fourth embodiments of the present invention Detailed view of the synchronous communication management table according to the third and fourth embodiments of the present invention Detailed view of synchronous communication resource data according to the third and fourth embodiments of the present invention Communication timing chart according to the third and fourth embodiments of the present invention The flowchart which shows the process sequence of the automatic allocation method of a synchronous communication resource in the master / slave synchronous communication system of Claim 4 of this invention Detailed view of synchronous communication resource data as an embodiment of claim 5 of the present invention Communication timing chart using the conventional method

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Master 11 Control period data 12 Slave detection part 121 Number of connected slaves 13 Slave allocation part 14 Synchronous communication management table 15 Cycle start packet reception process part 16 Command data transmission part 161 Command data 17 Response data reception part 171 Response data 18 Synchronous communication resource Acquisition / allocation unit 2i Slave 2i1 Command data reception unit 2i11 Command data 2i2 Response data transmission unit 2i21 Response data 2i3 Synchronous communication processing unit 2i31 Synchronous communication resource data 3 IEEE 1394 network 91 Header 92 data A
93 data B
94 data C
95 data D
96 data D bandwidth 97 Remaining bandwidth of isochronous transfer period

Claims (5)

In a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle.
The master
Means for acquiring control cycle data in which the control cycle is set;
Means for detecting the number of slaves connected on the IEEE 1394 network;
Means for allocating the slaves to isochronous cycles for the control period according to the control period data and the detected number of slaves;
Means for acquiring from the Isochronous Resource Manager a bandwidth and a channel that are synchronous communication resources for exchanging the communication data with the slave assigned to the isochronous cycle;
Means for creating a synchronous communication management table that includes the correspondence between the acquired synchronous communication resource and the slave and the allocation information to the isochronous cycle;
Means for notifying the slave of information of the associated synchronous communication resource;
Means for performing isochronous communication according to the synchronous communication management table,
The slave is
Means for receiving information of the synchronous communication resource from the master;
Means for performing isochronous communication based on information of the synchronous communication resource;
A master / slave synchronous communication system comprising: means for transmitting response data to the command data from the master. A master of a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle. In the automatic allocation method of synchronous communication resources in
Obtaining control cycle data in which the control cycle is set;
Detecting the number of slaves connected on the IEEE 1394 network;
Allocating the slaves so that the number of slaves is equal to isochronous cycles corresponding to the control period, based on the control period data and the detected number of slaves;
Obtaining from the Isochronous Resource Manager a bandwidth and channel that are synchronous communication resources for exchanging the communication data with the slave assigned to the isochronous cycle;
Creating a synchronous communication management table that includes the acquired synchronous communication resources and the correspondence between the slaves and the allocation information to the isochronous cycle;
Notifying the slave of information of the associated synchronous communication resource;
A method for automatically allocating synchronous communication resources, comprising: The master / slave synchronous communication system according to claim 1,
The master or the slave or each of the master and the slave comprises means having a data amount of the communication data,
The master / slave synchronous communication system, wherein the master includes means for calculating or reading the communication data amount for each slave. A master of a master / slave synchronous communication system in which one master and one or more slaves are connected to an IEEE 1394 network and the master and the slave exchange communication data in synchronization with a control cycle that is an integral multiple of an isochronous cycle. In the automatic allocation method of synchronous communication resources in
Obtaining control cycle data in which the control cycle is set;
Detecting the number of slaves connected on the IEEE 1394 network;
Calculating or reading the amount of communication data of all the slaves for each slave from the master or the slave or the master and the slave; and
Allocating the slaves to isochronous cycles such that the bandwidth used in each isochronous cycle is equal;
Obtaining from the Isochronous Resource Manager a bandwidth and channel that are synchronous communication resources for exchanging the communication data with the slave assigned to the isochronous cycle;
Creating a synchronous communication management table that includes the acquired synchronous communication resources and the correspondence between the slaves and the allocation information to the isochronous cycle;
Notifying the slave of information of the associated synchronous communication resource;
A method for automatically allocating synchronous communication resources, comprising: The master / slave synchronous communication system according to claim 1,
The master / slave synchronous communication system, wherein the slave includes a synchronous communication resource acquisition prohibition flag for selecting allocation of synchronous communication resources by the master.

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