JPH0344234A - Communication control system - Google Patents

Abstract

PURPOSE:To attain proper countermeasure even for a transmission data urgent transmission request caused periodically by allowing a master station to apply polling to a connection communication equipment of a system sequentially, deciding a transmission permission data quantity for each communication equipment and permitting the transmission. CONSTITUTION:A master station 400 is provided with a transmission request collection means applying polling sequentially to connection communication equipments 510, 550, 560 to the system at a prescribed cycle to collect transmission request data quantity for each communication equipment, a transmission enable quantity specifying means deciding the transmission enable data quantity for each communication equipment so that the transmission quantity for each communication equipment collected is processed within the prescribed cycle, and a polling output means outputting polling including the designation of the transmission data quantity allowing the transmission to the communication equipments 510, 550, 560. Moreover, each of the communication equipments 510, 550, 560 are provided with a data transmission means applying transmission processing at the reception of a polling from the master station 400 and a reply means. Thus, the data from the plural communication equipments 510, 550, 560 is communicated uniformly and proper processing is attained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to communication control in a communication system in which a plurality of communication devices are connected to each other via a communication medium and data communication is performed under the control of at least one master station device. It is related to the method.

[Background Art] In recent years, with the development of semiconductor technology, many small and inexpensive computer application products have appeared, and communication systems in which computers are connected to each other via communication media have been developed.

For this reason, the use of computers in hospitals is progressing, and systems are being developed that automatically perform measurements, especially for patients whose condition requires constant monitoring, and automatically transfer the measurement results to a monitoring room or center room. are also appearing.

Among these transfer methods, the output capacity of the transmission of measurement results using radio waves is kept low due to government regulations, and it is almost impossible to transfer measurement data over long distances.

Furthermore, in a communication system that transfers measurement data from the bedside to a monitoring room, center room, etc. via a communication medium, the communication method used in general-purpose computers is directly applied to the transfer process.

[Problems to be Solved by the Invention] For this reason, if the same communication control method as used in these general-purpose computers is used, data from multiple communication devices cannot be uniformly communicated among the devices, and data from specific devices cannot be communicated uniformly. Situations such as increased communication volume occurred, and it was not possible to perform appropriate processing while checking the measurement status of each device.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and includes the following configuration as a means for solving the above-mentioned problems.

That is, in a communication system in which a plurality of communication devices are connected to each other via a communication medium and perform data communication under the control of at least one master station device, the master station sequentially transmits data to the communication devices connected to the system at a predetermined cycle period. a transmission request collection means that performs polling to collect the amount of transmission request data for each communication device; comprising: a transmission request collection means for determining the amount of data to be permitted to be transmitted; and a polling output means for outputting polling including designation of the amount of data to be transmitted to each communication device;
Each communication device includes a data transmission means for transmitting data permitted to be transmitted when receiving polling from a master station to a desired communication device, and an amount of data that the master station requests to transmit from its own communication device in the next cycle. and a transmitting/receiving means that receives transmission data from other devices and transmits data that is permitted to be transmitted.

Further, a privilege request sending means capable of sending a privileged command sending request for controlling a direct communication device from the specific communication device to a master station at a predetermined allocated time of each cycle to the specific communication device;
Desired data receiving means is provided which outputs a privileged command to a desired communication device after sending the privileged command sending request and receives and receives predetermined data from the desired communication device, and when the privileged command sending request is received at the master station, the privileged command is sent to the desired communication device. and privileged command permission means for allocating communication time.

[Operation] In the above configuration, data transmission from each communication device is always ensured at a predetermined period, and periodically generated transmission data can be reliably and efficiently transferred to a desired device.

Furthermore, it is possible to remotely control a desired connected communication device more reliably and quickly than a specific communication device, and it is also possible to sufficiently respond to cases where data from the device is urgently required.

[Example] Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

In the following, a plurality of electrocardiogram analyzers that collect electrocardiogram waveforms as biological information and analyze the electrocardiogram waveforms are connected to each other via a LAN (500) that is a communication medium, and communication between the plurality of electrocardiogram analyzers is carried out in a single manner. A communication system that is managed and controlled by one master station will be explained as an example. However, the present invention is not limited to an electrocardiogram analysis device that processes such an electrocardiogram waveform, and can of course be applied to any communication device.

FIG. 1 is a system configuration diagram of an embodiment according to the present invention. In the figure, 400 is a master station that manages communication of this communication system by managing and controlling transmission rights to be described later, and 411 is a master station 400. A connected thermal printer. In this embodiment, the control of the master station 400 will mainly be explained as communication control, but it goes without saying that the master station 400 may also be constituted by other inter-station electrocardiogram analysis devices. In this case, it is sufficient to carry out the same control as, for example, the central monitor 510 as an electrocardiogram analysis device, at the same time as the communication control as a general master station.

Further, 500 is a communication medium, LAN, and 510 is a LAN.
A central monitor 500 is connected, a recorder 511 is connected to the central monitor 510 and stores electrocardiogram information, etc., and a bed site monitor 550 is placed at each bed side. 552 is an input box which is an external input interface; 553 to 555 are induction cords connected to the input box 552;
It is possible to collect biological information of the examinee on the floor. The guidance code 553
~555 is equipped with an electrode section for detecting biological information (electrocardiographic waveforms, etc.), a microphone for collecting heart rate, blood pressure values, etc. at the distal end.

In addition, 560 is a telemeter monitor placed at the bedside, and the telemeter input box 570 can be connected to the induction cord like other input pax.
Collected patient information from each patient's biological information collectors 573 to 575 is received wirelessly.

Each other's monitor devices (510, 550, 560)
It is possible to mutually send and receive collected information via N500,
Through communication control, which will be described later, it is possible to visually check information collected by other devices from a central monitor 510 installed in a nurse center or the like, for example.

Although only one bedside monitor 550 is shown in FIG. 1, up to 24 bedside monitors can be connected.

A block diagram of the monitor device having the above configuration is shown in FIG. FIG. 2 shows an example of a bedside monitor equipped with a recorder, and this bedside monitor will be described below as an example.

Even for other devices, the hardware configuration is between the two,
The only difference is the operational control. For example, a central monitor, etc. does not come with an input box or a guidance cord, and other controls are independent.

In FIG. 2, the same components as in FIG. 1 are given the same numbers, and detailed explanations are omitted.

In the figure, 1 is a CPU that is stored in the ROM 2 and controls the entire embodiment according to the program shown in FIG. 7, for example, and in the case of the master station 400, it controls communication according to the program shown in FIG. 2 is a ROM that stores the above-mentioned program as well as fixed parameters used in this example.
, 3 is a RAM for temporarily storing processing progress, etc., 5 is a DMA controller for transferring data between connected input/output devices using DMA, 21 is a display interface for controlling the display unit 200, and 22 is an operation panel 250
The operation panel interface that controls the interface with
23 is a sound generator that generates an acoustic signal output from the speaker 120, and 25 is a setting switch that sets various operating functions of the device of this embodiment, such as setting the monitor type. This setting selects which monitor will operate (central monitor, bedside monitor, telemeter monitor, master station, etc.).

27 is a printer interface that controls the thermal printer 300, 29 is a LAN interface that controls the interface with the LAN 500, and 30 is an input box 512.
31 is a timer circuit; 4
Reference numeral 0 designates a standby unit for causing the apparatus of this embodiment to operate again consistent with the operation when the power is turned off when the power is turned on again even if the power is turned off, and 45 is a power supply board.

Reference numeral 200 denotes a display unit, which in this embodiment is equipped with a CRT display device. Reference numeral 250 denotes an operation panel disposed on the display surface of the display unit 200, which is a touch panel that is a pressure-sensitive coordinate input device, and key functions corresponding to the display functions are assigned.

The control of a general electrocardiogram analysis device having the above configuration is almost the same as the control of the invention of the patent application (2) "Biological Information Processing System" filed by the applicant on May 16, 1989. Therefore, the communication control of the communication system of this embodiment having the above configuration will be explained below.

In this embodiment, the master station 400 operates in fixed time cycles (for example, in the configuration shown in FIG. 1, one cycle is 480 m5ec).
Each time, polling processing is performed for all connected monitor devices. As a result, the amount of data requested to be transmitted from each device is collected, and in response to the previously collected transmission request from each device, a transmission right delegation instruction including the amount of data to be permitted to be sent is sent out.

When each monitor device receives polling addressed to its own device from the master station, it checks the amount of data allowed to be sent for this polling and sends the permitted amount of data to the desired communication destination device or after polling. If the permitted amount is not available, the device immediately returns a return frame containing the amount of data that the device itself requests to transmit to another device to the master station, and transfers control to the master station.

The polling frame format used in this embodiment is shown in FIG. 3, and the return frame format for polling of this format from each monitor device is shown in FIG.
FIG. 5 shows the data transmission frame format from each device to another device.

In the figure, 611, 621, and 631 are control codes that represent the relevant frame type.

A code 611 indicates that the frame is a polling frame, a code 621 indicates that the frame is a return frame for the polling frame, and a code 631 indicates that the frame is a data transmission frame.

612, 622, and 632 are destination addresses indicating the destination device (transmission destination device) of the frame, and address values unique to each device are stored.

613, 623, and 633 are source addresses indicating the source device that transmitted the frame.

In addition, in the polling frame shown in FIG.
4 to 617 are areas for instructing transmission permission data to the destination device, and a permission flag is added to and sent only to the transmission request that permits transmission in response to the transmission request sent from the destination device in the previous cycle. It is something. If there are no transmission requests from each device, such as in the case of minimum communication, there is no corresponding area, and the frame simply functions as a frame for collecting transmission requests from each device.

In the return frame for polling in Figure 4, 6
24 to 627 are areas indicating the amount of data requested to be transmitted by the own device to another device and the destination device;
FIG. 4 shows that there are four pieces of transmission data. In these four areas, when there is a transmission request, a flag is set to '1', and 'request' stores the requested transmission data amount. In a portion where there is no transmission request, the flag is set to "0", and "request" is set to dummy data. Furthermore, in addition to the above-mentioned areas, a configuration may also be provided that includes a status information area 628 indicating the status of the device.

By using this format, the master station can know the status of each device at the time of polling.

Furthermore, in the data transmission frame shown in FIG.
is an area indicating the amount of data in the TEXT area 639, and 639 is a TEXT area in which transmission data for the destination device is stored.
This is an EXT area.

The communication control of the master station of the present embodiment using the above frames will be explained below with reference to the flowchart of FIG. 6, and the communication control of other monitor devices will be explained with reference to the flowchart of FIG. 7.

First, communication control of the master station 400 will be explained with reference to FIG.

The master station 400 first performs step S when starting up the system.
LAN 500 in broadcast command etc.
Collect the devices connected to and capable of data communication, the connected device configuration including the recorder type of each device, the alarm occurrence status, etc.

This collected data such as the network configuration can be received not only by the master station 400 but also by all other devices connected to the network, and is sequentially received and stored in the RAM 5 of the own device.
If an alarm is received, the alarm reception is displayed in a predetermined alarm display area of the display unit 200. Therefore, in the system of this embodiment, by looking at the display on the display unit 200 of all connected devices, it is possible to confirm the alarm state generated by any of the connected devices, and to take prompt action. Become.

Subsequently, in step S2, the polling frame shown in FIG. 3 is sequentially sent to each connected device.

Then, in step S3, the return frame shown in FIG. 4 is received, and the amount of data requested to be sent from each device and the device status are stored in a predetermined network management area in RAMa. In the following step S4, it is checked whether polling of all connected devices (slave stations) has been completed, and if there are still devices to be polled, the process returns to step S2 and polling of the next device is performed.

Note that the collection of the network configuration, etc., is not performed at the time of return for each polling, but may be performed all at once at every fixed cycle, and control may also be performed such that the collection is performed only when an alarm is generated.

On the other hand, when polling of all connected devices is completed, the process proceeds from step S4 to step S5, where the collected amount of data requested to be transmitted from each slave station is organized, and transmission is performed for each device that should be allowed to transmit in the next cycle. Determine the amount of data. The amount of data to be transmitted is determined within a range in which the execution time of next polling control, data transmission control, etc. is within a predetermined cycle time even if the data is transmitted. Note that the priority order of the transmission data is predetermined based on the content of the transmission data, and is set in order of priority for processing.

Subsequently, in step S6, the device status collected from each slave station is notified to each connected slave station by a broadcast command or the like.

This allows each slave station to recognize the system construction status and the status of the connected devices. And the following step S7
Then, it is checked whether a request to send remote key data is included in the request to send from each device. A remote key data transmission request is a request for a specific monitor device to remotely control another monitor device, and is a function that allows the specific monitor device to control the other device as if it were operating the operation panel. In this embodiment, only the central monitor 510 can request transmission of the remote key data.

If the remote key data transmission request is not included in step S7, the process advances to step Sll, and the first device (
A polling frame including transmission permission according to the transmission request is transmitted to the slave station). When the slave station receives the polling frame, it generates a transmission frame according to the data transmission format shown in FIG. 5 in order to transmit the permitted communication data, as will be described in detail later, if transmission is permitted. Send to desired destination device. After performing the transmission process, the return frame shown in FIG. 4 is transmitted to the master station. Incidentally, if there is no transmission request or the like and the transmission permission is not included, a new return frame shown in FIG. 4 containing the transmission request of the reading device is immediately generated and transmitted. For this reason, the master station 40
0 waits in step S12 for the transmission right to be returned by receiving a return frame from this slave station. If the response frame is not returned within the predetermined time, the process advances to step S13;
The slave station is considered to be in a communication-disabled state and is treated as being removed from the system. Then, the process advances to step S16.

On the other hand, when a return frame is received, step S12
The process then proceeds to step S15, where the amount of requested transmission data and the slave station status included in the return frame are registered in the management table in RAMa, as in step S3. Then, the process advances to step S16.

In step S16, it is checked whether polling of all devices connected in this cycle has been completed. If there is a device that has not been polled yet, the process advances to step S17, and the next device (slave station) to be polled is checked. Select and return to step Sll for the next connected device (slave station)
Performs polling processing.

When polling for all slave stations is completed in step S16, the process returns to step s5 and shifts to polling control for the next cycle.

On the other hand, if it is determined in step S7 that a remote key data transmission request is included, the process proceeds to step S20, where a key token flag is set, and each cycle is divided into four in subsequent step S21. In this example, l cycle is 480 m
5ec, which is divided into four cycles of 120 m5ec each. Then, the first fixed time (20 m5ec in this embodiment) of the cycle divided into four is allocated as a key stage for a key token and for communication of key data etc. corresponding to the key token.

Since this is the beginning of the cycle and the key stage, in the following step S22, a key polling request for remote key data transmission permission is sent to the remote key data transmission request sending device. And step S2
3.24, it is monitored whether a return frame for this key polling is received or whether the key stage has ended. The reason for monitoring the reception of the return frame in step S23 is that the remotely controlled device changes the control code 621 of the return frame to the control code 621 of the return frame at the key stage after completing the processing based on the control from the remote key data transmitting device. This is to return a control code frame indicating that the code area is a key stage return frame.

Therefore, if a return frame for the key stage is received here, the process proceeds from step S23 to step S26, where the key token flag is reset and set to stop dividing the cycle into four and shift to normal polling processing. . Then, the process advances to step Sll.

In addition, if the key stage ends here and it is normal polling execution time, step S24 is followed by step S3.
0, the slave station is polled, and in step S31, as in step S12, it is monitored whether a return frame in response to the polling is received. If the response frame is not returned within a predetermined period of time, the process proceeds to step S40, and as in step S13, the slave station is determined to be in a communicable state and is removed from the system, and the process proceeds to step S35.

On the other hand, when a return frame is received, step S31
The process then proceeds to step S32, and similarly to step S3, the transmission request data amount and slave station status included in the return frame are registered in the management table in RAMa. Then, in the following step S35, it is checked whether polling of all connected slave stations has been completed. When polling for all slave stations is completed, the process returns to step S21, and based on the amount of transmission request data etc. collected from each slave station,
The amount of data allowed to be transmitted for each slave station in the data communication area of each cycle divided into four is determined, and the status of each slave station is output by broadcast to notify the connected device.

If there is a slave station that has not yet been polled in step S35, the process advances to step S36, and the next slave station to be polled is selected. Then, in step S37, it is checked whether it is a key stage, that is, whether it is the beginning of one cycle time divided into four. Step S in case of key stage
Return to step S3 and if it is not the key stage, proceed to step S3.
Go to 0.

Through the above processing, optimal communication control can be performed for the communication system of this embodiment that analyzes electrocardiogram information. That is,
Even in processes where it is necessary to reliably transfer data, such as electrocardiogram information, that is regularly generated at regular intervals to the central monitor 510, it is possible to transfer this reliably and efficiently, and also to prevent alarm generation. In some cases, this can be reliably notified to each device so that it can be confirmed. Furthermore, even in such a case, other connected devices can be remotely controlled from the specific device, and the status can be grasped more quickly and more reliably.

Next, the communication control of each device (slave station) in accordance with the communication control of the master station will be described below with reference to FIG.

Each slave station checks in steps 351 to S53 whether there is data received from the connection communication LAN, whether there is a transmission request from its own device, or whether its own device is a specific monitor and a remote key has been pressed. Monitor.

In this state, when a transmission request is generated from the own device, the process advances from step S52 to step S55, and the generated transmission data is written into the transmission buffer in RAMa and also written into the transmission table. Then, return to step S51,
Wait for the transmission right to be acquired. This transmission table consists of the transmission destination address to which transmission is desired, the amount of data to be transmitted to the device, and the transmission data area, and the transmission request registered in this transmission table when polling from the master station, which will be described later, arrives. Read and send. In this embodiment, regularly generated electrocardiogram information, heart rate, blood pressure value, etc. are included. Among these, the alarm generation measurement value among the above data is given the highest priority, followed by the measurement data at the minimum cycle.

On the other hand, if the own device is the above-mentioned specific device (a device that can remotely control other devices such as a central monitor), other devices, such as a bedside monitor (only one is shown in Figure 1, but one parent) Up to 31 slave stations can be connected to the station (for example, 24 bedside monitors can be connected), and when you want to check the measurement data of other specified monitors or when an alarm occurs, etc. If you want to remotely control another device, enter the remote key. For example, if an alarm occurs on one of the bedside monitors on the network, the alarm will sound and the (Ikedoko) key will flash at the same time. Then, by operating the (ikedoko) key, the display screen can be moved to another store data display screen. As a result, a screen with collected data from the connected bedside where the alarm is occurring will be displayed (if the alarm is occurring on multiple beds at the same time, the floor with the lowest number will be displayed. (The keys on the remaining floors will flash to indicate which other floors are generating alarms.) Therefore, the biological information collected by the bedside monitor where the alarm occurred can be displayed and visually confirmed.

Therefore, in such a case, this function is used to input this remote key and obtain a more detailed understanding of the status.

In this case, the alarm sound from other stores will be the pond alarm sound (
It can be turned on/off using the ON) (OFF) keys.

In the above cases, step S53 to step S60
The process proceeds to step S61, confirms that the station is capable of remote key manual operation, and proceeds to step S61. Note that if the local station is a device that cannot be remotely controlled, the key input is invalidated and the process returns to step S51.

In step S61, key data indicating the address of the device desired to be remotely operated and the details of the operation is generated. Then, in step S62, this data is stored in the transmission table and transmission buffer, and the process returns to step S51 to wait for polling.

On the other hand, if data from the LAN is received, the process advances from step S51 to step S70, and it is checked whether the data is addressed to the local station. If the data is not received by the own station, the process returns to step S51. If the data is addressed to the own station, the process advances to step S71 to check whether or not the received frame is a polling frame.

If it is a polling frame, the process advances to step S72, and the amount of data allowed to be transmitted during polling is checked. If there is no transmission permission data, the process advances to step S75, and if the amount of transmission permission data has been specified, the process advances to step S73.

In step 373, the first transmission data for which transmission is permitted is transmitted to the desired destination device. And step S74
Check whether there is any other data that is allowed to be sent, and if there is still data that is allowed to be sent, go to step 37.
Return to step 3 and send the remaining data.

If all the data permitted to be transmitted in step S74 has been transmitted, the process advances to step S75.

In step S75, a return frame in response to the polling of the master station is generated and sent. This return frame includes a transmission request for data that has been registered in the transmission table and has not yet been transmitted, and state information (status information) of the device itself.

Then, the process returns to step S51 to prepare for reception of the next polling, etc.

With the above control, desired data can be transmitted to a desired device at a predetermined period.

On the other hand, if it is determined in step S71 that a polling frame has not been received, the process advances to step S76 to check whether key polling has been received. This key polling is sent at the first key stage when the own device first sends a remote key data transmission request with the above-mentioned specific device (a device that can remotely control other devices such as a central monitor). It is something that comes. If the own device is a specific device and receives the polling for the key, the process advances to step S80;
The device itself sends key data for the device to be remotely controlled to the desired device.

If it is determined in step 676 that key polling has not been received, the process advances from step S76 to step S82, and it is checked whether key data has been received from a specific device (central monitor). If key data is received, step S8
3, the same operation as when the own device key specified by the data is input is performed, and in the following step S84, a return frame in response to the operation is generated and stored in the transmission table and the transmission buffer. Then, in step S85, the key stage sends out a return frame for the remote key data to notify the end of the key stage. Note that this processing is performed completely separately from normal transmission/reception control, and the device also performs normal communication control at the same time as the above control.

As described above, it is possible to quickly respond to remote key operations that are frequently used in emergencies, and appropriate control can be performed even in the event of an emergency.

If the received data in step S83 is not key data, the process proceeds from step S83 to step S90, where the received data is stored in a predetermined area in the RAMB and processing corresponding to the received data is executed. This includes, for example, the process of registering the network table by receiving the system construction status through broadcast in step S6 in FIG. 6, and the like. Then, the process returns to step S51.

Here, the received data is displayed on the display 200, and if the received data is a network configuration or the like, corresponding processing is executed such as controlling subsequent data communication according to the received data.

Details of the normal communication control procedure described above are shown in FIG. 8, and details of the key token control communication control procedure are shown in FIG. 9, respectively.

As explained above, according to this embodiment, even in cases where transmission data is generated periodically and emergency transmission is required, such as from biological information measuring devices installed at each bedside, it can be handled appropriately. This allows for optimal treatment.

Furthermore, it is possible to remotely control a desired connected communication device more reliably and quickly than a specific communication device, and it is also possible to sufficiently respond to cases where data from the device is urgently required.

Furthermore, although the above description has been made regarding an electrocardiogram information collection/analysis device, the present invention is not limited to the above example, and can be applied to any biological information collection/monitoring device.

Furthermore, it goes without saying that the present invention can be applied not only to all biological information processing devices but also to information processing devices that require general data communication. It is especially suitable for devices that generate transmission data at regular intervals.

[Effects of the Invention] As explained above, according to the present invention, transmission rights can be obtained at regular intervals, and even periodically generated transmission data can be reliably and efficiently transmitted to a desired device. .

In addition, efficient communication is possible in which an appropriate response can be taken even to an emergency transmission request.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram of a biometric information processing system according to an embodiment of the present invention, Fig. 2 is a block configuration diagram of the biometric information processing device of this embodiment, and Fig. 3 is a diagram of the polling frame used in this embodiment. FIG. 4 is a diagram showing the detailed configuration of the return frame used in this embodiment. FIG. 5 is a diagram showing the detailed configuration of the data communication frame used in this embodiment. FIG. 7 is a flowchart of the communication control operation of the master station according to the embodiment. FIG. 8 is a diagram showing the normal communication control procedure of the embodiment. FIG. 9 is a flowchart of the communication control operation of the slave station according to the embodiment. FIG. 3 is a diagram showing a communication control procedure when there is communication of a key token. In the figure, 1...CPU, 2...ROM, 3...RA
M, 5...DMA controller, 21...Display controller, 22...Operation panel interface, 27...Printer interface, 29...L
AN interface, 30... External input interface, 200... Display unit, 250... Operation panel, 3
00゜511...Thermal printer, 400...Master station, 500...LAN, 512,552...Input box, 513-515, 553-555...Guidance code, 510,550,560- ...Monitor device, 57
0...Telemeter input box, 573-575.
...It is a biological information collector. Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) A communication control method in a communication system in which a plurality of communication devices are connected to each other via a communication medium and data communication is performed under the control of at least one master station, wherein the master station is connected to the system. The transmission request data amount for each communication device is collected by sequentially polling the communication devices at a predetermined cycle period, and the transmission permission data for each communication device is collected so that the collected transmission amount for each communication device is within the predetermined cycle period. When polling each communication device, a designation of the amount of data to be transmitted is output, and each communication device, upon receiving polling from the master station, transmits the permitted amount of data to the desired communication device. A communication control system characterized in that, after that, a new transmission request data amount from the own communication device is returned to the master station. (2) In the communication control method according to claim 1, the specific communication device is further enabled to send a privilege request to directly control another communication device from the specific communication device at a predetermined allocated time of each cycle, A communication control system characterized in that the specific communication device that is permitted to transmit based on a request can send control commands for other communication devices. (3) The communication control method according to claim 2, wherein the communication device that receives the control command from the specific communication device transmits the processing data under control from the specific communication device.