JP7696746B2 - Module System - Google Patents

Description

The present invention relates to a module system consisting of a host control device, one master module, and one or more slave modules, and to a technology for transmitting commands from the host control device to the master module or the slave module.

For example, in temperature control of hot press molding of carbon fiber reinforced plastics used in the exterior walls of aircraft fuselages, one master module is linked to multiple slave modules to control the heat sources of multiple targets. The master module receives control conditions for controlling the temperature of the multiple heating points to be controlled from a higher-level control device such as a PC or PLC (programmable logic controller), and transmits control signals (target temperature, manipulated variable, etc.) to the multiple slave modules connected to it based on the received control conditions. Then, each of the slave modules that receives these signals controls the controlled targets based on the received signals (Patent Document 1).

When controlling multiple heaters for the above temperature control and monitoring with thermometers, it is necessary to exchange commands and data quickly and reliably.

Currently, communication formats widely used for control devices include RS-485. RS-485 is a multi-point serial connection in a bus format that supports multi-drop, and specifies the electrical specifications of the physical layer. It has been improved to eliminate the shortcomings of the older, widely used RS-232C (one-to-one connection, short distance), and was developed after the RS-422, an improved version of RS-232C (one-to-10 connection possible, long distance compatible). RS-485 allows for many-to-many connections of up to 32-to-32, and like RS-422, has a maximum communication distance of up to 1200m and a maximum transmission speed of 10Mbps (due to the differential signaling method, the transmission speed decreases as the distance increases, and the transmission speed at the maximum distance is about 100kbps). Also, like RS-422, it uses a single-pulse differential signal on a twisted pair wire, and the common mode voltage, which is the average voltage of the twisted pair wire, is allowed to have a wide range of -7V to +12V, making it highly resistant to noise. For this reason, it has long been widely used for communication with control devices that are placed near noise sources such as manufacturing equipment.

On the other hand, Ethernet communication used for Internet lines is a method of packetizing data with a header and sending it, which is suitable for sending large amounts of data. However, the standard Ethernet communication does not guarantee communication speed or delay time due to its specifications. When watching videos on the Internet, the speed sometimes slows down or the image quality deteriorates because there are many users using the line or some users are communicating with large amounts of data. If communication fails due to noise, the communication may be retried, resulting in delays. When a master module used to control manufacturing equipment and the slave module are connected to each other via an Ethernet communication path, if multiple slave modules communicate with the master module at the same time, the packet transmission may interfere with each other and be canceled, or communication may fail due to noise and be delayed by retrying, or if another user who sends and receives large amounts of data is connected to the Ethernet communication path, the data communication speed may slow down, resulting in poor real-time performance. For this reason, serial communication such as RS-485, which is resistant to noise and has excellent real-time performance, has been adopted between the master module and the slave module.

Modbus is a communication protocol that uses RS-485 as the physical layer (electrical specification) and is widely used in industry. There are two types of Modbus protocols: Modbus RTU and Modbus ASCII, and later Modbus/TCP was added, which uses Ethernet as the physical layer.

In manufacturing processes such as temperature control of the molding hot press described above, one master module is connected to multiple slave modules to control the heat sources of multiple targets. Figure 6 shows a conventional example. A higher-level control device (0601), such as a PC or PLC, is connected to a communication module (0610) via Ethernet. The communication module (0610) converts between Ethernet communication signals and general-purpose serial communication signals (Modbus RTU). The communication module (0610) and the master module (0602) are connected via a serial communication path and communicate using general-purpose serial communication signals. The master module (0602) and slave module 1 (0603) to slave module n (0605) are cascaded using a serial communication path (serial communication I/F 1: RS-485). In Figure 6, the serial communication path is indicated by a dotted line, and the Ethernet communication path is indicated by a thick solid line. The slave module and master module (0602) are the same model, but the master/slave settings can be switched with a switch setting. One is set as the master and the other as the slave.

Multiple heaters (0606) and thermometers (0607) are attached to the workpiece (0608) inside the heating furnace (0609). Some of the heaters and thermometers are controlled/monitored by the master module (0602) itself. The remaining heaters and thermometers are controlled by slave module 1 (0603) through slave module n (0605), which are managed by the master module (0602). The higher-level control device (0601) sends commands to the master module (0602) via the communication module (0610) and receives responses from the master module.

JP 62-176295 Publication

As described above, in the module system for controlling the heating process shown in FIG. 6, commands from the higher-level control device (0601) are converted to general-purpose serial communication signals in the communication module (0610) without checking the contents of the signals, and are then sent to the master module (0602) and the slave module cascaded to the master module. The master module or slave module receives the signal addressed to itself and returns a response to the communication module. Although the RS-485 specification allows multiple units to be connected for communication via a serial communication path, the signal line is occupied while signals are being transmitted between the transmitting and receiving sides during communication, and so communication during that time is one-to-one. Therefore, while the communication module is communicating with the slave module, communication is not possible between the communication module and the master module, and similarly, while the communication module is communicating with the master module, communication is not possible between the communication module and the slave module.

The objective of the present invention is to enable signals including commands to be sent quickly from a higher-level control device to a master module and a slave module simultaneously.

In order to solve the above problems, the present invention provides:
A module system comprising: an upper control device (AA); one master module (BA) connected to the upper control device by an Ethernet communication path, which receives commands from the upper control device and outputs responses to the upper control device (AA); and one or more slave modules (CA) connected to the master module (BA) by a serial communication path which is a bus transmission path, which are modules directly managed by the master module (BA), which have a function of controlling functional components, and which are serially connected to each other by the bus transmission path;
The upper control device (AA) is
a master module command output unit (AB) for outputting a command to the master module (BA);
a master module response acquisition unit (AC) for acquiring a response from the master module (BA);
a slave module command output unit (AD) for indirectly outputting a command to the slave module (CA) via the master module (BA);
a slave module response acquisition unit (AE) for indirectly acquiring a response from the slave module (CA) via the master module (BA);
The device has a master module (BA) and an upper control device Ethernet communication unit (AF) for performing Ethernet communication with the master module (BA),
The master module (BA) is
A master module Ethernet transceiver unit (BB) for transmitting and receiving Ethernet communication signals with higher-level control devices;
a discrimination unit (BC) that discriminates whether a signal received by the master module Ethernet transceiver unit (BB) is addressed to itself or to a slave module (CA); a protocol conversion unit (BD) that converts the received Ethernet communication signal into a serial communication signal with the slave module when the discrimination result by the discrimination unit (BC) is that the signal is addressed to a slave, and converts a serial communication signal received from the slave module (CA) into an Ethernet communication signal as necessary;
A bus transmission/reception unit (BE) transmits the converted serial communication signal to a slave module (CA) via a bus transmission path, and receives a result corresponding to the transmission from the slave module (CA) via the same bus transmission path. If the result of the discrimination by the discrimination unit (BC) is that the signal is addressed to the master,
and a processing unit (BF) that performs processing directly based on the received Ethernet communication signal.

Furthermore, the present invention provides an operating method for a module system that is a computer, which comprises an operating method for an upper control device (AA) that is a computer corresponding to the module system of the present invention, and an operating method for a master module (BA) that is a computer.

Furthermore, an operating program that can be read into each of the computers, that is, the upper level control device (AA), corresponding to the module system of the present invention;
The present invention also provides an operating program that can be read into a module system, which is a computer, comprising an operating program that can be read into a master module (BA), which is a computer, for receiving commands from a higher-level control device (AA) and managing the module system itself or a slave module.
Furthermore, each of the operation programs may be recorded on a recording medium.

With this invention, the master module processes signals sent over the Ethernet communication path to the master module without converting them, and converts signals to the slave module into serial communication signals and transmits them to the slave module, making it possible to simultaneously and quickly receive and process communications from a higher-level control device to the master module and communications to the slave module.

FIG. 1 is a block diagram showing an example of a functional configuration of a module system according to a first embodiment. FIG. 1 is a flow chart showing a process flow of the module system according to the first embodiment. 1 is a hardware configuration diagram of a host control device of a module system according to a first embodiment of the present invention; FIG. 1 is a hardware configuration diagram of a master module of a module system according to a first embodiment. FIG. 1 is a schematic diagram showing an example of use of the module system according to the first embodiment; Schematic diagram showing an example of the use of a conventional module system An example of temperature control in a control system using a module system. FIG. 13 is a conceptual diagram showing an example of a common packet. FIG. 13 is a diagram showing an example of data shaping when transmitting from a higher-level control device to a slave module via a master module.

The following describes embodiments of the present invention with reference to the accompanying drawings. Note that the present invention should not be limited to these embodiments, and may be implemented in various forms without departing from the spirit of the present invention.

<Overview of control system including module system>

Figure 5 is a schematic diagram showing an example of a control system including a module system. In Figure 5, a processed workpiece (0508) is placed in a heating furnace (0509), heated by multiple heaters (0506), and the temperature of each part of the processed workpiece is measured by a thermometer (0507). This is an example of a control system that determines whether the measured temperature is within a predetermined temperature range and controls the output of the heater (0506). The module system of the present invention is not limited to the example of heating processing shown in Figure 5, and can be used in various other types of control systems. Note that the difference from the control system conceptual diagram of Figure 6 showing the conventional technology is the presence or absence of a communication module.

A higher-level control device (0501), such as a PC or PLC, is connected to a LAN line (Ethernet) (0500), and a master module (0502) is similarly connected to the LAN line (0500). The master module (0502) and higher-level control device (0501) communicate, including sending commands and responses, via the LAN line (Ethernet). The master module (0502) can manage one or more slave modules. A slave module controls multiple heaters and receives measurement values from multiple thermometers. The master module may be responsible for controlling some heaters and thermometers.

In response to the transmission from the master module, slave module 1 (0503) through slave module n (0505) transmit the temperature data they have acquired as a response to the master module (0502) via a serial communication path (including a bus transmission path; the same applies below. In some cases, a parallel bus may also be used.) When the temperature data is configured so that the master module can recognize that it is within a planned management range, the master module may be configured to perform continuous temperature management of the slave modules based on that recognition.

A serial communication path is used to connect the master module (BA) and the slave module (CA). This is because, as mentioned above, real-time communication is important when controlling machining, i.e., communication must always be performed at a fixed time. As serial communication paths, a general-purpose serial communication path (RS-485 serial bus with Modbus RTU protocol), an internal bus that is a high-speed serial bus with a physical layer RS-485 based on the Modbus RTU protocol, and an internal bus that is relatively slower than the high-speed internal bus can be used. The high-speed internal bus is fast, at 1 Mbps or more, and is used to connect the master module and slave module, and between slave modules. The general-purpose serial communication path has a maximum speed of 115.2 kbps, but in addition to the master module and slave module, it is possible to connect other recorders with a general-purpose serial communication path and record data, and commands can be issued from higher-level connected devices via the master module.

The following relationship can be established regarding the control relationship between the master module and the slave module.

<Master-slave control relationship, slave-independent state type>
FIG. 7 shows, from the top, examples of temperature profile settings for the master module, slave module 1, slave module 2, and slave module n with respect to temperature control. The vertical axis of each graph indicates temperature, and the horizontal axis indicates time. The top graph in FIG. 7 shows the temperature profile set in the master module. In the example of FIG. 7, the temperature is increased at a constant rate, maintained for a certain time, slightly decreased, and then maintained at a constant temperature for a certain time again, and then decreased to the original temperature. Each slave module holds its own difference information with respect to the settings of the master module. The temperature profile of each slave module (solid line) in FIG. 7 is a correction of the temperature profile of the master module by applying its own difference information based on the temperature profile held by the master module. The dotted line is the temperature profile of the master module shown for reference. In the temperature profile of the slave module, the time of the inflection point of the temperature profile (the point where the profile changes, such as changing from a flat state to a rising temperature, changing from a rising temperature to a maintained temperature, or changing from a maintained temperature to a falling temperature) is the same for both the master module and the other slave modules. Based on the difference information of the slave module, the temperature value or the slope of the temperature profile when the temperature is rising or falling may differ. Each slave module does not have its own temperature profile, but only stores difference information, and performs control by correcting the difference information by referring to the temperature profile stored in the master module as needed. Each slave module may be configured to store its own temperature profile. Based on each temperature profile, each slave performs PID control of each heater under its control in accordance with automatic control theory.

In Figure 5, in order to absorb and adjust the differences due to factors such as the structure and composition distribution of the workpiece (0508), the temperature distribution in the heating furnace (0509), the output variation of each heater, and the error of each thermometer, the setting profile of each slave module must be modified based on the setting profile of the master module, otherwise the workpiece cannot be heated according to the desired temperature distribution and temperature profile. Therefore, each slave module applies its own difference information to the temperature profile of the specified master module, and performs heating according to the setting temperature profile of each slave module. The results from the thermometer managed by each slave module are sent to the master module, which converts the serial communication signal to an Ethernet communication signal and sends it to the upper control device (AA). The master module (BA) also sends the information of the thermometer managed by itself to the upper control device. In this case, it can be sent as an Ethernet communication signal without signal conversion.

Each of the parts described below can be realized as a combination of hardware and software. Specifically, if a computer is used, the hardware components include a CPU, main memory, bus, or secondary storage device (non-volatile memory such as flash memory or SSD, storage media such as CD or DVD, and a drive for reading these media), an input device used to input information, a PLC, a recorder, a printer or display device, and other external peripheral devices, as well as interfaces for these external peripheral devices, communication interfaces, driver programs and other application programs for controlling these hardware, and user interface applications. Then, the CPU performs calculations according to the program deployed on the main memory to process and store data input from input devices and other interfaces and stored in memory or a hard disk, and to generate commands for controlling the above hardware and software. Alternatively, the functional blocks of this device may be realized by dedicated hardware.

In addition, each embodiment described in this specification can be realized not only as an operating method, but also as a device, part or all of which can be realized. Furthermore, part of such a device can be configured as software. Furthermore, software products used to cause a computer to execute such software, and recording media on which such products are fixed, are naturally included in the technical scope of each embodiment described in this specification (the same applies throughout this specification).

<Embodiment 1>
<Overview of First Embodiment>

This is a module system consisting of a master module connected to a higher-level control device via a LAN (Ethernet (registered trademark)) line, and one or more slave modules connected to the master module via a serial communication path.The master module is configured to receive and process communication from the higher-level control device as an Ethernet communication signal if the communication is addressed to itself, and to convert it to a serial communication signal and transmit it if the communication is addressed to a slave module.
<Functional Configuration of First Embodiment>

1 is a block diagram showing an example of the functional configuration of a module system according to the present embodiment. As shown in the figure, the module system of the present invention comprises an upper control device (AA) (0100) consisting of a master module command output unit (AB) (0101), a master module response acquisition unit (AC) (0102), a slave module command output unit (AD) (0103), a slave module response acquisition unit (AE) (0104), and an upper control device Ethernet communication unit (AF) (0105);
A master module (BA) (0150) consisting of a master module Ethernet transmission/reception unit (BB) (0151), a discrimination unit (BC) (0152), a protocol conversion unit (BD) (0153), a bus transmission/reception unit (BE) (0154), and a processing unit (BF) (0155);
It has a slave module (CA) (0170).

<Embodiment 1: Master module command output unit (AB) (0101)>
The master module command output section (AB) (0101) of the higher level control device (AA) is configured to output commands to the master module (BA).

The higher-level control device (AA) outputs commands to the master module (BA) via Ethernet communication signals. Ethernet communication signals generally use the TCP/IP protocol. The packets of communication protocols such as Modbus/TCP, which conform to the TCP/IP protocol but are formulated for specific applications, all have their own formats for the data retention format within the payload, but the data frames are the same as those of the TCP/IP protocol, and these packets are called common packets.

Figure 8 (a) shows a "TCP/IP packet," and Figure 8 (b) shows a "Modbus/TCP packet" as an example of a common packet.

As shown in Figure 8 (a), a TCP/IP packet consists of a TCP header and a payload. The TCP header stores "management information" related to transmission, such as the source port number, destination port number, sequence number, and acknowledgment number. The payload stores the "data body."

As shown in FIG. 8(b), Modbus/TCP packets also contain a "data body" with a "Modbus application header," which is the header of the Modbus protocol, added within the payload of the data frame of the TCP/IP packet.

When the higher-level control device (AA) outputs a command to the master module (BA) or slave module (CA), it outputs it with a device management number for identification purposes. For example, the master module (BA) is numbered #1, and the slave module (CA) is numbered #2, #3, or other numbers greater than one. This is used by the discrimination unit (BC) (0152) of the master module (BA), which will be described later, to determine whether the command is addressed to the master module or the slave module.

The device management number is written as an address using the unit ID contained in the Modbus application header. For signals addressed to a slave module, a discrimination section in the master module (described below) first divides the signal into two categories: master module or slave module. If the signal is addressed to a slave module, the signal is then protocol converted and converted into a serial communication signal, after which the device management number in the payload is used to determine which slave module it is addressed to, in a two-stage discrimination.

<First embodiment: Master module response acquisition unit (AC) (0102)>
The master module response acquisition unit (AC) (0102) of the higher level control device (AA) is configured to acquire a response from the master module (BA).

<Embodiment 1: Command output unit (AD) for slave module (0103)>
The slave module command output unit (AD) (0103) of the host control device (AA) is configured to indirectly output commands to the slave module (CA) via the master module (BA). The transmission of information (command output) from the host control device to the slave module is performed indirectly via the master module that can communicate with the host control device.

Similar to the above-mentioned master module command output unit (AB) (0101), when the higher-level control device (AA) outputs a command to the slave module (CA), it outputs an equipment management number (or, in some cases, a decipherable port number) such as #2, #3, or a number greater than 2 for identification purposes.

<First embodiment: Slave module response acquisition unit (AE) (0104)>
The slave module response acquisition unit (AE) (0104) of the higher-level control device (AA) is configured to indirectly acquire responses from the slave module (CA) via the master module (BA). In other words, information is transmitted from the slave module to the higher-level control device via the master module that can directly communicate with the higher-level control device.

<Embodiment 1: Upper control device Ethernet communication unit (AF) (0105)>
The upper control device Ethernet communication unit (AF) (0105) of the upper control device (AA) is configured to perform Ethernet communication with the master module (BA).

The command with the device management number attached, output from the master module command output unit (AB) and slave module command output unit (AD) of the higher-level control device (AA), is sent to the master module (BA) as an Ethernet communication signal. It also receives a response signal by the Ethernet communication signal sent from the master module (BA), and outputs the response to the master module response acquisition unit (AC) or slave module response acquisition unit (AE) according to the device management number attached to the signal.

<Embodiment 1: Upper control device (AA) (0101)>
The upper level control device (AA) (0101) is configured to issue commands to the master module (BA) connected via an Ethernet communication path and receive responses.

The master module and slave module of the module system of the present invention are likely to be installed in a control panel near the manufacturing equipment at the manufacturing site. The usage form is that commands are output to the master module from a higher-level control device (AA) in a management room or the like that is separated from the control panel of the manufacturing equipment and connected via an Ethernet communication path, and data is received. A desktop PC or a notebook PC can also be used as the higher-level control device (AA). The received data can be conveniently used to create documents or for analysis.

<Embodiment 1: Master module Ethernet transceiver (BB) (0151)>
The master module Ethernet transceiver (BB) (0151) of the master module (BA) is configured to transmit and receive Ethernet communication signals to and from a higher-level control device. The master module Ethernet transceiver is configured to be able to execute processes independently of the bus transceiver (BE) described later. In other words, the process of the other is not restricted or is restricted only very little when either one is transmitting or receiving. "Extremely little" refers to a case where the utilization efficiency of the hardware resources of the CPU, MPU, and communication-dedicated LSI is restricted. However, such restrictions are only generated when extremely special conditions (for example, a large amount of processing data generated due to an unexpected programming error) are met, and are configured not to occur in general processing.

<Embodiment 1: Discrimination unit (BC) (0152)>
The discrimination unit (BC) (0152) of the master module (BA) is configured to discriminate whether the Ethernet communication signal received by the master module Ethernet transceiver unit (BB) (0151) is addressed to itself or to the slave module (CA).

The device control number attached to the command output from the higher-level control device (AA) determines whether the command is addressed to the master module itself or a slave module. If the device control number is written as a unit ID in the Modbus application header in the payload of the common packet of the Ethernet communication signal, the unit ID is read as an address and used to determine whether the command is addressed to the master module (BA) itself or to one or more slave modules. If it is addressed to a slave module, the protocol conversion unit described below performs subsequent processing. If it is addressed to the master module itself, the processing unit described below performs subsequent processing.

<Embodiment 1: Protocol Conversion Unit (BD) (0153)>
The protocol conversion unit (BD) (0153) of the master module (BA) is configured to convert the received Ethernet communication signal into a serial communication signal with the slave module when the discrimination result in the discrimination unit (BC) is that the signal is addressed to a slave, and to convert the serial communication signal received from the slave module (CA) into an Ethernet communication signal as necessary.

Modbus/TCP can be used as the Ethernet communication signal, and Modbus RTU protocol can be used as the serial communication signal such as RS-485. Figure 9(a) shows a common packet, and as shown in Figure 9(b), a local packet consisting of a "Modbus application header" and a "data body" is obtained from the common packet. Then, as shown in Figure 9(c), the "Modbus application header", which is the header of the local packet, is removed leaving only the unit ID contained in the Modbus application header. The unit ID is added to the beginning of the data body as an address, and if the downstream protocol is Modbus RTU (Remote Terminal Unit) mode, a CRC is added, and if it is Modbus ASCII (American Standard Code Information Interchange) mode, it is converted to ASCII code and an LRC is added.

As shown in FIG. 9(d), the data is then shaped into a Modbus protocol message frame, which is a serial communication protocol packet used for communication with a slave module. The "address" corresponds to the "unit ID" included in the Modbus application header. The function code sets the function that the master module will cause the slave module to execute. The "data" stores data related to the function code. The data shaped in this way becomes the shaped data to be transmitted from the master module to the slave module. Although the Modbus protocol is used in this example, in the case of other protocols, the header can be removed according to the protocol and the data can be shaped into the serial communication protocol data format used for communication with the slave module. When converting the protocol for a response from the slave module to a higher-level control device, the above steps are reversed.

<Embodiment 1: Bus Transmitter/Receiver (BE) (0154)>
The bus transceiver unit (BE) (0154) of the master module (BA) is configured to transmit the converted serial communication signal to the slave module (CA) via a bus transmission path, and to receive a result corresponding to the transmission from the slave module (CA) also via the bus transmission path.

As a bus for serial communications, an RS-485 serial bus of the Modbus RTU protocol, an internal bus based on Modbus RTU, etc. can be used. The master module bus transceiver unit (BE) is configured to be able to execute processes independently of the master module Ethernet transceiver unit (BB) described above. In other words, the fact that one of them is transmitting or receiving does not restrict the processing of the other, or restricts it only very little. "Very little" refers to cases where the efficiency of use of the hardware resources of the CPU, MPU, and communication-dedicated LSI is restricted. However, such restrictions only arise when very special conditions are met (for example, a large amount of processing data is generated due to an unexpected programming error), and are configured not to arise in general processing.

<Embodiment 1 Processing Section (BF) (0155)>
The processing unit (BF) (0155) of the master module (BA) is configured to directly carry out processing based on the received Ethernet communication signal when the discrimination result in the discrimination unit (BC) indicates that the signal is addressed to the master.

<Embodiment 1: Master Module (BA) (0150)>
The master module (BA) (0150) is configured to receive commands from a higher-level control device (AA) connected via an Ethernet communication path and output responses, and is also configured to be connected via a serial communication path, which is a bus transmission path, to one or more slave modules (CA) which are serially connected to each other via a bus transmission path, and to directly manage them.

<Embodiment 1: Slave module (CA) (0170)>
The slave module (CA) (0170) is one or more slave modules serially connected to each other via a bus transmission line, and is configured to have a function of controlling functional components.

The functional component control function refers to a function that manages one or more thermometers or controls heaters, for example (but is not limited to this function). One control method is one in which each slave module has differential information and performs PID control of each heater it manages based on the temperature profile of the master module, as in the above-mentioned "master-slave control relationship, slave independent state type."

When engineers or workers change PCs when working in shifts, or when accessing from a location other than the normal control room due to teleworking, etc., to view past status history or command history, a security authentication unit is provided at the Ethernet communication inlet of the master module, and the system is configured so that workers with access authority, administrators with management authority, and members of the systems department can access the system after being authenticated. The system references the access authority information stored in association with user information stored by authentication means such as passwords, biometric authentication, or magnetic records, ICs, or wireless tags built into employee ID cards, and determines whether or not the user has access authority, and then authenticates the user.

Once authenticated, the module system of the present invention can be used according to the access rules that indicate the access range according to the access authority held. For example, the access rules include guest authority to only view the history information stored in the database to check the status, the current status of the master module and/or slave module, general authority to perform routine processing tasks, and administrator authority without restrictions (not limited to this classification). Once authenticated, a session ID is issued for communication between the PC used at the time of access and the master module. While communication continues, a session ID is attached to the communication, indicating that the access has been authenticated. Even if processing work is ongoing, communication can be terminated when the worker is replaced due to a day/night shift change. In that case, the session ID is discarded, and a different session ID is issued to the worker who starts accessing in place. Teleworkers who work from home outside the security controlled area of a factory or the like, or people on business trips outside the factory, can connect to the factory's internal LAN line via a VPN server, access the security authentication unit of the master module, and obtain authentication.

<Processing flow of embodiment 1>
Figure 2 shows the process flow of the module system of embodiment 1. The part on the left surrounded by a dashed line shows the process flow in the upper control device (AA), and the part on the right surrounded by a dashed line shows the process flow in the master module (BA). The slave module (CA) is located at the bottom right, communicating with the master module (BA) via a serial communication path. The process within the slave module (CA) is not shown.
In the upper control device (AA),
First, a process is performed to determine whether a command is to be issued to the master module or to the slave module (SA0201).
When the upper control device (AA) sends a command to the master module (BA),
The step (ab) of outputting a command to the master module (SA0202) outputs a command to the master module (BA),
When the higher-level control device (AA) transmits a command to the slave module (CA), a slave module command output step (ad) (SA0203) performs processing to indirectly output the command to the slave module (CA) via the master module (BA), and a higher-level control device Ethernet communication step (af) (SA0204) performs processing to communicate with the master module (BA) via Ethernet.
The master module response acquisition step (ac) (SA0205) performs a process of acquiring a response from the master module (BA),
The slave module response acquisition step (ae) (SA0206) performs processing to indirectly acquire a response from the slave module (CA) via the master module (BA).

In the master module (BA),
The master module Ethernet transmission/reception step (bb) (SB0201) performs processing to receive an Ethernet communication signal from the upper control device (AA),
The determination step (bc) (SB0202) performs processing to determine whether the Ethernet communication signal received in the master module Ethernet reception step (bb) (SB0201) is addressed to itself or to the slave module (CA),
If the determination result in the determination step (bc) (SB0202) is that the signal is destined for the master module, a processing step (bf) (SB0203) performs processing based on the received Ethernet communication signal, and outputs the processed result to the master module Ethernet transmission/reception step (bb) as necessary.
If the determination result in the determination step (bc) (SB0202) is that the message is addressed to a slave module,
A protocol conversion step (bd) (SB0204) converts the received Ethernet communication signal into a serial communication signal with a slave module,
The bus transmission/reception step (be) (SB0205) transmits the converted serial communication signal to the slave module (CA) via a bus transmission path, receives a result corresponding to the transmission from the slave module (CA) also via the bus transmission path, and outputs the result to the protocol conversion step (bd) as necessary.
The protocol conversion step (bd) (SB0206) converts the serial communication signal received from the slave module (CA) into an Ethernet communication signal as necessary and outputs the signal to the master module Ethernet transmission/reception step (bb) (SB0207).
The master module Ethernet transmission/reception step (bb) (SB0207) performs processing for transmitting an Ethernet communication signal to the higher-level control device (AA).
This is an operating method for causing the module system to execute such a series of processes.

<Embodiment 1 Hardware>

Figure 3 is a conceptual diagram showing an example of the hardware configuration of the upper control device (AA) of the module system of this embodiment. As shown in the figure, it is considered that the upper control device (AA) will often use a PC or the like, and has a configuration similar to that of a PC. It is composed of a "CPU", a "chipset" consisting of a north bridge and a south bridge, "non-volatile memory", "main memory", "I/O controller", "USB, IEEE 1394, LAN terminal, etc.", "BIOS", "PCI slot", "real-time clock", etc.

The various programs and data (information) stored in the non-volatile memory are expanded into the main memory when the system is started, and the programs are configured to perform calculations using the data in sequence by the CPU upon receiving execution commands.

As shown in FIG. 3, the non-volatile memory of the upper control device (AA) contains, in addition to the OS (operating system) and device drivers, a master module command output program, a master module response acquisition program, a slave module command output program, a slave module response acquisition program, and an upper control device Ethernet communication program, and holds data such as master module commands, master module responses, slave module commands, and slave module responses. These are expanded into the main memory when the system is started on the computer, and upon receiving a start command, the CPU sequentially performs calculations using the programs and data, and exchanges commands and responses with the master module or with the slave module via the master module. The non-volatile memory of the upper control device (AA) may also contain a control program that manages and displays information about the control system that uses the master module, as well as other business software programs.

Figure 4 is a conceptual diagram showing an example of the hardware configuration of the master module (BA) of the module system of this embodiment. As shown in the figure, it is equipped with a CPU (0401), a non-volatile memory (0402) (e.g., ROM, SSD, etc.), a main memory (0403), an Ethernet communication I/F (0404) (interface is abbreviated as I/F in Figure 4) for connection with a control PC or a recorder, a general-purpose serial communication interface I/F1 (0405) for connection with a control module, etc., a user I/F (0406), a bus controller (0409) for controlling a communication I/F (0411) with an internal bus (0410), a controller DMAC (0408) for performing a DMA method (a method of transferring data to and from a memory without going through a CPU) during internal bus transmission, and a system bus (0407) for transmitting and receiving signals between them. A customized dedicated CPU can be used as the CPU, and dedicated firmware can be used instead of an OS (operating system). Additionally, a system with a multi-core CPU and/or sufficient cache memory is preferable, as it makes it easier to prevent operational delays due to memory shortages.

In addition to the operating system and device drivers, non-volatile memory also contains
A master module Ethernet transmission/reception program that transmits and receives Ethernet communication signals to and from higher-level control devices;
a discrimination program for discriminating whether the received Ethernet communication signal is addressed to itself or to a slave module (CA);
a processing program for directly processing the received Ethernet communication signal when the determination result in the processing program indicates that the signal is addressed to a master;
a protocol conversion program that converts the received Ethernet communication signal into a serial communication signal with a slave module when the discrimination result of the discrimination program indicates that the signal is addressed to a slave, and converts a serial communication signal received from the slave module (CA) into an Ethernet communication signal as necessary;
Various programs and specific port numbers, such as a bus transmission/reception program that transmits the converted serial communication signal to the slave module (CA) via a bus transmission line and receives the result according to the transmission from the slave module (CA) also via the bus transmission line, are recorded. Then, each program is deployed and executed, and information and data acquired via the interface are stored in a non-volatile memory, and the stored information and data are processed by executing the program in the work area of the main memory, and are retained in the non-volatile memory, or are output to the upper control device (AA) by executing the program via the Ethernet communication interface.
<Effects of First Embodiment>

According to the module system of this embodiment, by integrating the communication module and master module of the conventional technology, the upper control device (AA) and the master module (BA) are connected by a high-speed Ethernet communication path. Therefore, commands from the upper control device (AA) to the master module (BA) are processed in the master module (BA) without being converted to a serial communication signal, and a response is sent to the upper control device (AA) as necessary. Commands to the slave module (CA) are converted to a serial communication signal in the master module (BA) and then sent. By changing the signal protocol of the command to the master module and the command to the slave module, for example, commands from the above control devices can be communicated to the master module quickly at the same time, whereas in the past, the serial communication path was a bottleneck and communication to the slave module was not possible until communication was completed.

0100 Upper control device (AA)
0101 Master module command output section (AB)
0102 Master module response acquisition unit (AC)
0103 Slave module command output section (AD)
0104 Slave module response acquisition unit (AE)
0105 Upper control device Ethernet communication part (AF)
0150 Master Module (BA)
0151 Master module Ethernet transceiver (BB)
0152 Discrimination section (BC)
0153 Protocol conversion unit (BD)
0154 Bus Transmitter/Receiver (BE)
0155 Processing Section (BF)
0170 Slave module (CA)

Claims (3)

a host control device (AA); and one master module (BA) connected to the host control device (AA) via an Ethernet communication path, which receives commands from the host control device (AA) and outputs responses to the host control device (AA); the master module (BA) has a general-purpose serial communication path (RS-485 serial bus of Modbus RTU protocol) to which an external device can be connected as a serial communication path, an internal bus which is a high-speed serial bus of the physical layer RS-485 based on the Modbus RTU protocol, and one or more slave modules (CA) which are connected via a serial communication path which is an internal bus relatively slower than the high-speed internal bus, are modules which are directly managed by the master module (BA), have a function of controlling functional components, and are serially connected to each other via a bus transmission path;
A modular system comprising:
The upper control device (AA) is
a master module command output unit (AB) for outputting a command to the master module (BA);
a master module response acquisition unit (AC) for acquiring a response from the master module (BA);
a slave module command output unit (AD) for indirectly outputting a command to the slave module (CA) via the master module (BA);
a slave module response acquisition unit (AE) for indirectly acquiring a response from the slave module (CA) via the master module (BA);
The device has a master module (BA) and an upper control device Ethernet communication unit (AF) for performing Ethernet communication with the master module (BA),
The master module (BA) is
A master module Ethernet transceiver unit (BB) for transmitting and receiving Ethernet communication signals to and from an upper control device (AA);
a discrimination unit (BC) that discriminates whether an Ethernet communication signal received by the master module Ethernet transceiver unit (BB) is addressed to itself or to a slave module (CA); and a protocol conversion unit (BD) that converts the received Ethernet communication signal into a serial communication signal with the slave module when the discrimination result by the discrimination unit (BC) is that it is addressed to a slave, and converts a serial communication signal received from the slave module (CA) into an Ethernet communication signal as necessary;
A bus transmission/reception unit (BE) transmits the converted serial communication signal to a slave module (CA) via a bus transmission path, and receives a result corresponding to the transmission from the slave module (CA) via the same bus transmission path. If the result of the discrimination by the discrimination unit (BC) is that the signal is addressed to the master,
and a processing unit (BF) that performs processing directly based on the received Ethernet communication signal. A method for operating a module system which is a computer comprising: an upper control device (AA); and one master module (BA) which is connected to the upper control device (AA) via an Ethernet communication path and receives commands from the upper control device (AA) and outputs responses to the upper control device (AA); the master module (BA) is a general-purpose serial communication path (RS-485 serial bus of Modbus RTU protocol) to which an external device can be connected as a serial communication path; an internal bus which is a high-speed serial bus of RS-485 physical layer based on Modbus RTU protocol; and one or more slave modules (CA) which are connected via a serial communication path which is an internal bus relatively slower than the high-speed internal bus , are modules which are directly managed by the master module (BA), have a function of controlling functional components, and are serially connected to other slave modules (CA) via a bus transmission path;
The operation method of the upper control device (AA), which is a computer, is as follows:
a step (ab) of outputting a command to a master module (BA);
a step (ac) of acquiring a response from the master module (BA);
a slave module command output step (ad) for indirectly outputting a command to the slave module (CA) via the master module (BA);
a slave module response acquisition step (ae) of indirectly acquiring a response from the slave module (CA) via the master module (BA);
A master module (BA) and an upper control device Ethernet communication step (af) for performing Ethernet communication with the master module (BA),
The operation of the Master Module (BA), which is a computer, is as follows:
A master module Ethernet reception step (bb) for transmitting and receiving Ethernet communication signals to and from a higher-level control device;
a determination step (bc) of determining whether the Ethernet communication signal received by the master module Ethernet receiving step (bb) is addressed to itself or to a slave module (CA); and a protocol conversion step (bd) of converting the received Ethernet communication signal into a serial communication signal with a slave module and, if necessary, converting a serial communication signal received from the slave module (CA) into an Ethernet communication signal, if the determination result in the determination step (bc) is that the signal is addressed to a slave module;
a bus transmission/reception step (be) of transmitting the converted serial communication signal to a slave module (CA) via a bus transmission path and receiving a result corresponding to the transmission from the slave module (CA) also via the bus transmission path; and if the determination result in the determination step (bc) is that the signal is addressed to the master,
and (bf) performing direct processing based on the received Ethernet communication signal. an operating program that can be loaded into a module system that is a computer that includes a host control device (AA), one master module (BA) that is connected to the host control device (AA) via an Ethernet communication path, that receives commands from the host control device (AA) and outputs responses to the host control device (AA); the master module (BA) includes a general-purpose serial communication path (RS-485 serial bus of Modbus RTU protocol) that can connect an external device as a serial communication path, an internal bus that is a high-speed serial bus of RS-485 physical layer based on Modbus RTU protocol, and one or more slave modules (CA) that are connected via a serial communication path that is an internal bus that is relatively slower than the high-speed internal bus , that are modules that are directly managed by the master module (BA), that have a function of controlling functional components, and that are serially connected to other slave modules (CA) via a bus transmission path;
The operating program that can be loaded into the upper control device (AA), which is a computer, is
a step (ab) of outputting a command to a master module (BA);
a step (ac) of acquiring a response from the master module (BA);
a slave module command output step (ad) for indirectly outputting a command to the slave module (CA) via the master module (BA);
a slave module response acquisition step (ae) of indirectly acquiring a response from the slave module (CA) via the master module (BA);
A master module (BA) and an upper control device Ethernet communication step (af) for performing Ethernet communication with the master module (BA),
The operating program that can be loaded into the master module (BA), which is a computer, is
A master module Ethernet reception step (bb) for transmitting and receiving Ethernet communication signals to and from a higher-level control device;
a determination step (bc) of determining whether the Ethernet communication signal received by the master module Ethernet receiving step (bb) is addressed to itself or to a slave module (CA); and a protocol conversion step (bd) of converting the received Ethernet communication signal into a serial communication signal with a slave module and, if necessary, converting a serial communication signal received from the slave module (CA) into an Ethernet communication signal, if the determination result in the determination step (bc) is that the signal is addressed to a slave module;
a bus transmission/reception step (be) of transmitting the converted serial communication signal to a slave module (CA) via a bus transmission path and receiving a result corresponding to the transmission from the slave module (CA) also via the bus transmission path; and if the determination result in the determination step (bc) is that the signal is addressed to the master,
and a processing step (bf) for directly processing the received Ethernet communication signal.

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