JP4851828B2 - Surveillance control system, transmission relay device of the system, and transmission method - Google Patents

Description

  The present invention relates to a data transmission system for connecting a plurality of networks in a supervisory control system, and in particular, to monitor data transmission between networks that are asynchronously transmitted at different transmission cycles. The present invention relates to a control system, a transmission relay device of the system, and a transmission method.

  In monitoring and control systems such as steel, water and sewage, petrochemical, electric power, automobiles, and other industrial equipment, data is transmitted using a network such as a LAN within the same building in order to transmit control data. It is carried out.

  Since this data transmission needs to be performed quickly, each node (transmission equipment) that has acquired the transmission right uses periodic cyclic transmission (also referred to as scan transmission) in which transmission is performed sequentially and sequentially. Yes.

  In addition, since there is an optimum number of nodes to be incorporated into one network, when the scale of the control system is increased, a plurality of sub-networks are constructed and connected by transmission relay apparatuses that connect these networks. ing.

  Since transmission relay devices that connect such networks require data exchange with high responsiveness between devices, an information exchange method using a shared memory that can be accessed without being aware of the transmission device is adopted. Yes.

  When sending and receiving broadcast transmission data between networks equipped with a shared memory, each transmission relay device that connects the networks to each other is equipped with a shared memory, and data is transferred between the shared memories. Since the data is then sent to the other network, there is a problem that the transmission speed of the broadcast transmission data between the networks decreases.

  For this reason, a plurality of networks, each having a plurality of nodes connected to a transmission path, are connected to each other, and transmission data that is cyclically transmitted to each transmission path is transmitted to other networks. In the transmission relay device to be sent to the path, the data stored in the shared memory in the transmission relay device of this network is address-converted and sent to the transmission path of the other network, between the shared memories that have been conventionally performed There has been disclosed a technique capable of omitting data transfer and improving the data transmission speed between networks (for example, see Patent Document 1).

  In addition, conventional transmission relay devices between subnets that divide a large-scale network may not be able to create healthy information because it does not know that cyclic transmission is stopped, or it cannot relay on the shortest route. there were.

  In such a transmission relay device that relays a subnet, it is possible to relay the suspension of cyclic transmission at each station, and in a system having a plurality of transmission relay devices, it is possible to relay on the shortest route, A subnet transmission relay device is disclosed that can automatically select a relay on another route when the transmission relay device fails (see, for example, Patent Document 2).

  However, in a monitoring control system in which multiple networks are asynchronously transmitted at different transmission cycles, the timing of data transmitted varies depending on the transmission cycle, so that the control performance varies and the control stability is affected. There was a problem.

  Problems of such a monitoring control system will be described with reference to FIGS. FIG. 7 shows the configuration of the monitoring control system.

  This supervisory control system includes a plurality of transmission relay apparatuses 13 (13-1 to 13-n) for relaying different broadcast cyclic transmission LANs including a high-speed control LAN 14 and a low-speed device LAN 17, and a device LAN 17 The detection data of the terminal transmitted from a plurality of device transmission apparatuses 15 (15-11 to 15-nn) connected to (17-1 to 17-n) is transmitted and controlled by the monitoring control apparatus 11 that controls the system. is doing.

  FIG. 8 shows the timing of the transmission signal of this broadcast cyclic transmission. In FIG. 8A, each transmission relay device 13 connected to the loop-type control LAN 14 circulates the token signal st (st1 to stn) at a transmission cycle Tc, and transmits each data to a shared memory (not shown). Indicates the state.

  On the other hand, in FIG. 8B, each device transmission apparatus 15 connected to the bus-type device LAN 17 circulates the token signal sd (sd1 to sdn) through the transmission cycle Td, and each is not shown in a shared memory (not shown). The state which is transmitting the data transmitted from each device (apparatus) is shown.

  The transmission period Tc of the control LAN 14 restricts the control period of the system, and this transmission period is normally set in the range of 1 msec to 100 msec, but is set in advance from the required control responsiveness.

  The transmission period Td of the device LAN 17 is normally set in the range of 100 milliseconds to several seconds, but the response speed required by each device is different. The shortest is the transmission period Td, and the longest is transmitted in a time n times Td.

  In addition, the transmission cycle of the control LAN 14 and the device LAN 17 is controlled asynchronously with the transmission cycle Tc (seconds) <the transmission cycle Td (seconds).

Therefore, as shown in FIG. 8B, the transmission data from the device transmission device 15 transmitted in the transmission cycle Td of the shortest time is the time recognized by the monitoring control device 11 for the time corresponding to the transmission cycle Tc. Therefore, there is a problem that the control performance of the supervisory control system is not stable.
JP-A-5-327730 JP-A-5-336118

  In conventional monitoring and control systems, the transmission cycle between multiple networks is asynchronous and transmitted at different transmission cycles, resulting in variations in the timing of data collection by the monitoring and control device, and stable control performance There was no problem.

  The present invention has been made to solve the above-described problems. In a monitoring control system in which a plurality of networks are connected, device data transmitted to a monitoring control device of a high-speed control LAN is transmitted to the device network. To provide a monitoring and control system, a transmission relay device of the system, and a transmission method that stabilize the control performance by adjusting the transmission timing from the device device connected to the control network to the transmission cycle of the control network. Objective.

To achieve the above object, the monitoring control system of the present invention, asynchronous, and a monitoring control device connected to a network of heat transmission cycle that different, transmission relay device for relaying the plurality of devices transmitting device, the a monitoring and control system Ru provided with,
One of the transmission relay devices is connected to the monitoring control device via a control network that is transmitted in a first transmission cycle defined by a request of the monitoring control system, and the other is connected to the first transmission cycle. Monitoring that controls the supervisory control system by device data generated by the device transmission apparatus that is connected via the device network that is transmitted in the second transmission period of the slower period and that is transmitted through the transmission relay apparatus a control device, wherein the monitoring and control system to a time server for supplying a reference time, and the time transmitter for generating an internal clock signal by receiving the time signal from the time server, controlling access to one of the control network a second transmission control unit for controlling a first transmission control unit, access to the other of said device network, said first transmission system A shared memory for storing a device data is broadcast cyclically transmitted in the second transmission cycle from the control data and the second transmission control section in the first transmission cycle are transmitted broadcast cyclically from parts, The transmission period is obtained from the transmission right signal transmitted from the first transmission control unit, and supplied from the time transmission unit when a change in the cyclic transmission period exceeding a preset reference value is detected. by adding a reference time time corresponding to the transmission cycle, in the shared memory and a first transmission control operation unit to be stored as the reference time data, the reference time data stored in said shared memory, said device network A transmission relay apparatus comprising a second transmission control arithmetic unit that performs broadcast cyclic transmission via the transmission relay apparatus and the reference time data transmitted from the transmission relay apparatus. Received via the chair network, the seeking transmission time of the device data in advance to be transmitted from the DeviceNet network, and device transmission apparatus that synchronously transmitted broadcast cyclically a first transmission periodic of the control network The device data is transmitted in synchronization with a first transmission period of the control network.

To achieve the above object, the transmission relay device of the monitoring control system of the present invention, asynchronous, and a monitoring control device connected to a network of heat transmission cycle that different, and a plurality of devices transmitting apparatus, a relay a transmission relay device Ru monitoring and control system comprising a transmission relay device, the transmission relay device, one via the control network to be transmitted by the first transmission period which is defined at the request of the supervisory control system The other is connected to the monitoring and control apparatus, and the other is connected via a device network that is transmitted in a second transmission cycle that is slower than the first transmission cycle, and receives a time signal from the time server and internally and time transmitting section for generating a clock signal, a first transmission control unit that controls access to one of the control network, access to the other of said device network A second transmission control unit for controlling, in the first and the second transmission cycle from the control data and the second transmission control unit from the transmission control unit is broadcast cyclically transmitted in the first transmission cycle of The transmission cycle is determined from the device data to be broadcast and transmitted, the shared memory to be stored, and the transmission right signal transmitted from the first transmission control unit, and the cyclic transmission cycle equal to or higher than a preset reference value . when a change is detected by adding the reference time time corresponding to the transmission cycle supplied from the time transmitter unit, a first transmission control operation unit to be stored as reference time data in the shared memory, wherein A transmission relay device comprising a second transmission control calculation unit that performs the cyclic transmission of the reference time data stored in a shared memory via the device network, and It characterized in that the device data was to receive in synchronism with a first transmission cycle of the control network.

To achieve the above object, a method of transmitting monitoring and control system of the present invention, asynchronous, and relays the monitoring control device connected to a network of heat transmission cycle that different, and a plurality of devices transmitting device, the a method for transmitting monitoring and control system Ru with a transmission relay device, the transmission relay device, one, the monitoring over the control network to be transmitted by the first transmission period which is defined at the request of the supervisory control system is connected to the control device, the other is connected via a device network transmitted in the second transmission cycle of the slower cycle than the first transmission period, the device transmission transmitted via the transmission relay device a monitoring controller for controlling the monitoring and control system by the device data generated by the device, a time server for supplying a reference time to the monitoring and control system, before Controlling a time transmitter for generating an internal clock signal by receiving the time signal from the time server, a first transmission control unit that controls access to one of the control network, access to the other of said device network A second transmission control unit; control data broadcasted from the first transmission control unit in the first transmission cycle; and broadcast data transmitted from the second transmission control unit in the second transmission cycle. The transmission cycle is obtained from the device data to be cyclically transmitted, the shared memory to be stored, and the transmission right signal transmitted from the first transmission control unit, and the cyclic transmission cycle is changed more than a preset reference value. when it is detected by adding the reference time time corresponding to the transmission cycle supplied from the time transmitter unit, the first to be stored as reference time data in the shared memory A transmission relay device comprising: a transmission control arithmetic unit; and a second transmission control arithmetic unit that broadcasts the reference time data stored in the shared memory via the device network, and the transmission relay device the reference time data transmitted from, and received through the device network, the seeking transmission time of the device data to be transmitted from the DeviceNet network in advance, synchronized to the first transmission periodic of the control network and a device transmitting apparatus for transmitting broadcast cyclically Te, detects the reference time data corresponding to the first transmission cycle of the control network, there is a change in the first transmission cycle of the control network The reference time data is broadcast cyclically via the device network, The reference time data is received, and the transmission time of the broadcast cyclic data of the second transmission period transmitted from the device device is obtained in advance, and the data is broadcast from the device device when the transmission time is reached. The device data is transmitted in synchronization with a first transmission period of the control network.

  According to the present invention, when the transmission cycle of the transmission line of the control network having one transmission cycle earlier and the time of the transmission cycle signal are detected as reference time data, and it is determined that a change has occurred in the transmission cycle. Broadcasts the reference time data to each device transmission apparatus connected to the device network via the other device network having a slower transmission cycle, and transmits the respective device transmissions that have received the reference time data. The apparatus obtains the transmission time of its own device transmission apparatus in advance, and broadcasts the data of its own device at that time.

  Therefore, according to the present invention, the data of each device is broadcast and transmitted in synchronization with the transmission cycle of the control network that controls the system. Provided are a monitoring control system, a transmission relay device of the system, and a transmission relay method capable of obtaining stable control performance without causing variations in transmission timing from each device even when the cycle changes due to some change. I can do it.

  An embodiment according to the present invention will be described with reference to FIGS. The configuration of the monitoring control system of the present invention is shown in FIG.

  The supervisory control system of the present invention is an asynchronous and different transmission comprising a supervisory control device 1 for controlling the system, a time server 2 for supplying a reference time, a loop-type control LAN 4 and a bus-type device LAN 7. A plurality of transmission relay devices 3 that relay broadcast transmission data between networks that perform broadcast cyclic transmission at a period, and a plurality of devices that are connected to the device LAN 7 (7-1 to 7-n) and transmit device data It consists of a device transmission apparatus 5 (5-11 to 5-nn).

  The monitoring control device 1, the transmission relay device 3, and the device transmission device 5 are connected to a time server 2 that supplies a reference time signal, and each internal clock can be calibrated with high accuracy. Has been.

  Next, the detailed configuration of each unit will be described. First, the network will be described.

  The control LAN 4 and the device LAN 7 are, for example, a LAN (Local Area Network) such as Ethernet (registered trademark), and may be any LAN that uses the IEEE 802.4 standard or IEEE 802.5 standard and uses a token passing system. The topology may be either a bus or a loop (also called a ring).

  An optimal transmission rate is set in advance from the scale of the monitoring control system and the required control response performance. Normally, the transmission speed 4 of the control LAN 4 is selected to be 10 to 100 times the transmission speed of the device LAN 7 from the control response required for the system.

  Next, the monitoring control device 1 receives device data for each device detected by a device (not shown) transmitted from the device transmission device 5 transmitted via the plurality of transmission relay devices 3, and performs a predetermined calculation. And a function for monitoring the system abnormality by determining whether or not the system state is normal.

  Next, the configuration of the transmission relay device 3 that relays data communicated between the monitoring control device 1 and the device transmission device 5 will be described with reference to FIG.

  The transmission relay device 3 receives a reference time signal from the time server 2 that transmits a reference time to be supplied to each part of the monitoring control system and generates an internal clock signal, and a transmission period signal of the control LAN 4 A first transmission control calculation unit 32 that determines whether or not the transmission cycle has been changed and adds a time to the determined transmission cycle signal (time stamp), and a transmission cycle change from the first transmission control calculation unit 32 The second transmission control calculation unit 33 is configured to perform a multicast transmission to the device LAN 7 using the transmission period and the time stamped as a reference time data.

  Furthermore, a shared memory unit 34 that stores control data that is cyclically transmitted via the control LAN 4 and device data that is cyclically transmitted via the device LAN 7, and a first transmission control unit that controls access to the control LAN 4 35 and a second transmission control unit 36 that controls access to the device LA74.

  Next, details of each of these units will be described. The time transmitter 31 receives, for example, a time signal from a GPS, and receives a time signal from a time server 2 including a GPS clock that outputs a GPS time signal synchronized with UTC (Universal Time Coordinated). ) Part 31b and an internal clock (RTC) 31a for generating a time signal calibrated with 1 mS unit accuracy synchronized with the GPS clock from the received time signal.

  The first transmission control calculation unit 32 is configured by an MPU-S 32a formed of a microprocessor, a RAM 32b that is a work memory thereof, and a FROM 32c that stores a control program for controlling the own transmission relay device 3.

  The MPU-S 32a, the RAM 32b, the FROM 32c, and the RTC 31a are each connected to the internal bus 3a.

  The second transmission control calculation unit 33 includes an MPU-D 32a made of a microprocessor, a RAM 33b that is a work memory thereof, and a FROM 33c that stores a control program for controlling the own transmission relay device 3. The MPU- D33a, RAM 33b, and FROM 33c are connected by an internal bus 3b.

  The first transmission control unit 35 includes a MAC-S 35a that controls access to the control LAN 4 and its communication interface unit 35b. The MAC-S 35a is connected to the bus 3c1 of the MPU-S 32a.

  Similarly, the second transmission control unit 36 includes a MAC-S 36a that controls access to the device LAN 7 and its communication interface unit 36b, and the MAC-S 36a is connected to the bus 3c2 of the MPU-S 33a.

  The bus 3c1 of the MPU-S 32a and the bus 3c2 of the MPU-D 34a are connected via the bus arbiter 34b. Access to the shared memory 34a connected to the bus arbiter 34b is connected to the MPU-S 32a via the bus arbiter 34b. It is controlled in cooperation with the MPU-D 34a.

  In the shared memory 34a, at least storage areas for control data transmitted via the control LAN 7, device data transmitted via the device LAN 7, and reference time data are determined in advance.

  Next, the details of the device transmission apparatus 5 will be described with reference to FIG. The device transmission apparatus 5 includes a time transmission unit 51 that receives a reference time signal from the time server 2 that transmits a reference time and generates an internal clock signal, and a transmission control calculation unit that controls data transmitted and received via the device LAN 7 52, a shared memory 54 that stores data shared with the transmission relay device 3, and a transmission control unit 55 that controls access to the device LAN 7.

  Next, details of each of these units will be described. The time transmission unit 51 has the same configuration as the time transmission unit 31 and calibrates with an I / F (interface) unit 51b that receives a time signal from the time server 2 and with 1 mS unit accuracy synchronized with the GPS clock from the received time signal. And an internal clock (RTC) 51a for generating a time signal of the device itself.

  Further, the transmission control calculation unit 52 includes an MPU-S 52a formed of a microprocessor, a RAM 52b that is a work memory thereof, and a FROM 52c that stores a control program for controlling the own device transmission apparatus 5.

  The MPU-S 52a, RAM 52b, FROM 52c and RTC 51a are connected by an internal bus 5a.

  The shared memory 54 is connected to the internal bus 5a, and stores the same data as the shared memory 34a of the transmission relay device 3 connected to the device LAN 7.

  The transmission control unit 55 includes a MAC-S 55a that controls access to the device LAN 4 and its communication interface unit 55b. The MAC-S 55a is connected to the bus 5c of the MPU-S 32a.

  Then, the device transmission apparatus 5 transmits the reference time data received by the transmission control unit 55 via the device LAN 7 to the transmission control calculation unit 52, and the transmission control calculation unit 52 transmits next from the own device transmission apparatus 5. The transmission time of the device data is obtained, the device data of the own device transmission apparatus 5 is commanded to the transmission control unit 55, and the transmission control unit 55 performs broadcast cyclic transmission via the device LAN 7 at the timing when the commanded transmission time is reached. .

  Next, referring to FIG. 4, reference time data including the transmission period of the control LAN 7 and the time of the transmission period signal, which is obtained by the transmission relay apparatus 3 and is broadcast and transmitted cyclically, and the device transmission apparatus 5 to the device Device data that is broadcast cyclically transmitted via the LAN 7 will be described.

  FIG. 4A shows an example of transmission frame data of reference time data that is broadcast cyclically transmitted. This frame data includes the address D31 of the destination for broadcast transmission, the address D52 of the transmission source (transmission relay device 3) that transmits this, the frame type of this data, and the transmission period (seconds) detected by the own transmission relay device 3 ), Reference time data D34 including the time of the transmission cycle signal, and a frame check sequence (FCS) D35.

  This data is broadcast and transmitted every time the transmission relay device 5 determines that the transmission cycle has changed to a predetermined value or more.

  FIG. 4B shows an example of a transmission frame of device data that is broadcast cyclically transmitted. This frame data includes a destination address 511 for broadcast transmission, an address D52 of a transmission source (own device transmission apparatus 5) for transmitting the frame data, a frame type D53 of this data, and a device input to the own device transmission apparatus 5 It consists of data D54 and frame check sequence (FCS) D55.

  Then, this data is obtained from the device transmission apparatus 5 based on the received reference time data, and the transmission time of the own apparatus set in advance is obtained. In synchronization with the transmission cycle time of the control LAN 4, the data is transmitted via the device lAN 7. Click transmission.

  Next, a device data transmission operation in the network of the monitoring control system configured as described above will be described with reference to FIGS.

  In FIG. 5 (a), each transmission relay apparatus 3 connected to the control LAN 4 circulates the token signal st (st1 to stn) in the transmission period Tc and transmits each data to the shared memory 34a. The time chart of st is shown.

  Further, in FIG. 5B, each device transmission apparatus 5 connected to each device LAN 7 circulates the token signals sd (sd1 to sdn) in the transmission cycle Td, and the shared memory 34a and the shared memory 54 A time chart of a transmission periodic signal sd for transmitting input data transmitted from each device (apparatus) is shown together with a time chart of the transmission periodic signal st.

  Next, an operation for generating such a transmission cycle signal sd will be described with reference to the flowchart of FIG.

  First, the operation of the transmission relay apparatus 3 that detects a change in the transmission period of the control LAN 4 and performs broadcast cyclic transmission of the reference time data will be described with reference to FIG.

  The transmission cycle Tc is detected from the token signal st of the first transmission control unit 35 and transmitted to the MPU-S 32a. In the MPU-S 32a, the transmission time is time stamped from the token signal st by the clock of the time transmission unit 31, and stored in the RAM 32b.

  Then, the change is measured according to a predetermined criterion (s1). When the measurement is performed for the first time (s2), the transmission cycle and the initial value of the time are set (s3). This initial value may be transmitted from the second transmission control calculation unit 33 of the transmission relay device 3 or set by each device transmission device 5 itself.

Changes are detected in the second and subsequent measurements. For example, when this detection value is ΔTc and the determination reference value is α, the following expression is used.
ΔTc = Tci−Tci ₋₁ > α
However, Tci = Tsti-Tsti- ₁ (seconds)
Tci ₋₁ = Tsti ₋₁ −Tsti ₋₂ (seconds)
Here, Tsti is the time of the i-th token signal, and Tci is the i-th transmission cycle (time). α is the timepiece accuracy, for example, 1 msec.

  If it is determined that there is a change, the MPU-S 32a notifies the MPU-D 33a of the second transmission control calculation unit 32 (s4).

  The MPU-S 33a transmits the notified transmission cycle and time as reference time data at the timing when the transmission right of the device LAN 7 is acquired (s5).

  In FIG. 5, the transmission period between the token signal st1 to the token signal st5 is Tc0, the change ΔTc is detected between the token signal st6 to the token signal st7, and then the token signal sd4 for acquiring the transmission right in the device LAN7. It is shown that it was transmitted at the timing of.

  Accordingly, the device data while detecting the change and transmitting the detected reference time data is temporarily out of synchronization so that, for example, Δt becomes Δtx as shown in FIG. It becomes normal within the range in which the transmission right of the device LAN 7 goes around.

  Next, with reference to FIG. 6B, a transmission operation of the device transmission apparatus 5 that performs multicast transmission of device data based on the transmitted reference time data will be described.

  Each device transmission apparatus 5 receives the transmitted reference time data by the transmission control unit 55 and notifies the MPU-S-52a of the data (s11).

  The MPU-S-52a obtains the next transmission time of the own device transmission apparatus 5 from the reference time data as Δt seconds before the time of the transmission period of the control LAN 4, and notifies the transmission control unit 55 of the time (s12). ).

  Then, the transmission control unit 55 determines the transmission time with the clock of the time transmission unit 51, acquires the transmission right in the device LAN 7, and broadcasts the device data at the notified time.

  In FIG. 5B, this timing is shown as a token signal sd4. As described above, the device transmission apparatus 5 and the transmission relay apparatus 3 include the calibrated internal clock, and can transmit the transmission time from the device transmission apparatus 5 in synchronization with the transmission period of the control LAN 4.

  The present invention is not limited to the above-described embodiments, and the network may be a wireless LAN according to system requirements, and various modifications can be made without departing from the gist of the present invention. .

The block diagram of the monitoring control system of this invention. The block diagram of the transmission relay apparatus of this invention. The block diagram of the device transmission apparatus of this invention. The example of the frame data of the reference time information of this invention. The time chart explaining the transmission operation of the network of this invention. The flowchart explaining the transmission operation of the network of this invention. The block diagram of the conventional monitoring control system. Explanatory drawing of the transmission operation | movement of the network of the conventional monitoring control system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Monitoring and control apparatus 2 Time server 3 (3-1 to 3-n) Transmission relay apparatus 4 Control LAN
5 (5-11 to 5-nn) Device device 7 (7-1 to 7-n) Device LAN
11 Monitoring and Control Device 13 (13-1 to 13-n) Transmission Relay Device 14 Control LAN
15 (15-11 to 15-nn) Device device 17 (17-1 to 17-n) Device LAN
31 Real Time Transmitter 31a RTC
31b I / F
32 1st transmission control calculating part 32a MPU-S
32b RAM
32c FROM
33 2nd transmission control calculating part 33a MPU-S
33b RAM
33c FROM
34 shared memory unit 34a shared memory 34b bus arbiter 35 first transmission control unit 35a MAC-C
35b Communication I / F
36 Second transmission control unit 36a MAC-C
36b Communication I / F
51 Real Time Transmitter 51a RTC
51b I / F
52 Transmission Control Operation Unit 52a MPU-S
52b RAM
55c FROM
54 shared memory unit 54a shared memory 54b bus arbiter 55 transmission control unit 55a MAC-C
55b Communication I / F

Claims (3)

Asynchronous, and a monitoring control device connected to a heat transmission period of the network that different, a monitoring and control system Ru with a transmission relay device for relaying the plurality of devices transmitting apparatus, a
One of the transmission relay devices is connected to the monitoring control device via a control network that is transmitted in a first transmission cycle defined by a request of the monitoring control system, and the other is connected to the first transmission cycle. Connected via a device network that is transmitted in a second transmission cycle of a slower cycle,
A supervisory control device that controls the supervisory control system by device data generated by the device transmission device transmitted via the transmission relay device ;
A time server for supplying a reference time to the monitoring control system;
Control and time transmitter for generating an internal clock signal by receiving the time signal from the time server, a first transmission control unit that controls access to one of the control network, access to the other of said device network The second transmission control unit, the control data broadcasted from the first transmission control unit in the first transmission cycle, and the control data transmitted from the second transmission control unit in the second transmission cycle. Information on cyclic transmission device data, shared memory to be stored, transmission right signal transmitted from the first transmission control unit to determine its transmission cycle, change of the cyclic transmission cycle more than a preset reference value the but if it is detected by adding the reference time time corresponding to the transmission cycle supplied from the time transmitter unit, it is stored as the reference time data in the shared memory A transmission control calculation unit, the reference time data stored in the shared memory, and the transmission relay device via the device network and a second transmission control calculation unit that transmits broadcast cyclically
The reference time data transmitted from the transmission relay device is received via the device network, and a transmission time of the device data to be transmitted from the device net network is obtained in advance, and a first transmission cycle of the control network is obtained. A device transmission device that performs broadcast cyclic transmission in synchronization with the period ,
With
A monitoring control system, wherein the device data is transmitted in synchronization with a first transmission period of the control network. Asynchronous, and a monitoring control device connected to a network of heat transmission cycle that different, a transmission relay device monitoring and control system Ru with a transmission relay device for relaying the plurality of devices transmitting apparatus, a
One of the transmission relay devices is connected to the monitoring control device via a control network that is transmitted in a first transmission cycle defined by a request of the monitoring control system, and the other is connected to the first transmission cycle. Connected via a device network that is transmitted in a second transmission cycle of a slower cycle,
A time transmitter for receiving a time signal from the time server and generating an internal clock signal;
A first transmission control unit that controls access to one of the control network, the other of the second transmission control unit that controls access to the device network, the first from the first transmission control unit Shared data for storing control data that is broadcast cyclically transmitted in a transmission cycle and device data that is broadcast cyclically transmitted in the second transmission cycle from the second transmission control unit;
The transmission period is obtained from the transmission right signal transmitted from the first transmission control unit, and supplied from the time transmission unit when a change in the cyclic transmission period exceeding a preset reference value is detected. by adding a reference time time corresponding to the transmission period, a first transmission control operation unit to be stored as reference time data in the shared memory,
A second transmission control calculation unit that transmits the reference time data stored in the shared memory via the device network in a cyclic manner;
With
A transmission relay apparatus for a supervisory control system, wherein the device data is received in synchronization with a first transmission period of the control network. Asynchronous, and a monitoring control device connected to a network of heat transmission cycle that different, a transmission method of monitoring and control system Ru with a transmission relay device for relaying the plurality of devices transmitting apparatus, a
One of the transmission relay devices is connected to the monitoring control device via a control network that is transmitted in a first transmission cycle defined by a request of the monitoring control system, and the other is connected to the first transmission cycle. Monitoring that controls the supervisory control system by device data generated by the device transmission apparatus that is connected via the device network that is transmitted in the second transmission period of the slower period and that is transmitted through the transmission relay apparatus A control device;
A time server for supplying a reference time to the monitoring control system;
Control and time transmitter for generating an internal clock signal by receiving the time signal from the time server, a first transmission control unit that controls access to one of the control network, access to the other of said device network The second transmission control unit, the control data broadcasted from the first transmission control unit in the first transmission cycle, and the control data transmitted from the second transmission control unit in the second transmission cycle. Information on cyclic transmission device data, shared memory to be stored, transmission right signal transmitted from the first transmission control unit to determine its transmission cycle, change of the cyclic transmission cycle more than a preset reference value the but if it is detected by adding the reference time time corresponding to the transmission cycle supplied from the time transmitter unit, it is stored as the reference time data in the shared memory A transmission control calculation unit, the reference time data stored in the shared memory, and the transmission relay device via the device network and a second transmission control calculation unit that transmits broadcast cyclically
The reference time data transmitted from the transmission relay device is received via the device network, and a transmission time of the device data to be transmitted from the device net network is obtained in advance, and a first transmission cycle of the control network is obtained. A device transmission device that performs broadcast cyclic transmission in synchronization with the period ,
With
Detecting the reference time data corresponding to the first transmission period of the control network;
When there is a change in the first transmission period of the control network, the reference time data is broadcasted cyclically via the device network,
Receiving the reference time data, obtaining in advance the transmission time of the broadcast cyclic data of the second transmission period to be transmitted from the device device,
Broadcast data from the device device at the time of the transmission time,
A transmission method for a supervisory control system, wherein the device data is transmitted in synchronization with a first transmission period of the control network.

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