Patent Publication Number: US-2022236723-A1

Title: Production assisting device, production system, and recording medium

Description:
TECHNICAL FIELD 
     The present disclosure relates to a production assisting device, a production system, and a program. 
     BACKGROUND ART 
     In a factory production line, a production line device is controlled with a programmable logic controller (PLC) module. In a system including the PLC module, input or output of data to or from a remote module through a communication network is performed in accordance with a control program executed by a central processing unit (CPU) module. The CPU module inputs and outputs data to and from the remote module to control a sensor and a motor connected to each channel in the remote module. A typical system includes distributed remote modules, to and from which data is input and output individually (see, for example, Patent Literature 1). 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: International Publication No. WO 2015/162754 
     SUMMARY OF INVENTION 
     Technical Problem 
     At the start or change in a production line, the operation of each remote module is to be checked one after another. For such operational checks, a production-line start company such as a system integrator creates, using an engineering tool, a control program for monitoring the operation of each remote module one after another by reading input and output values from the remote module, or a control program for collectively monitoring the operations of the multiple remote modules. When the control program for monitoring the operation of each remote module one after another is executed by the CPU module, the input and output values of each remote module are individually read and displayed on a display screen, to enable checking the operation of each remote module individually. For example, inclusion of ten remote modules leads to performing ten times of a work that includes reading the input and output values of each remote module, displaying the input and output values on the display screen, and individually checking the operation of each remote module. The control program for collectively monitoring the operations of the ten remote modules is complex, and creating such a control program takes a long time. Starting such a production line thus takes a long time. 
     In response to the above issue, an objective of the present disclosure is to simplify a work to start or change a production line. 
     Solution to Problem 
     To achieve the above objective, a production assisting device according to an aspect of the present discourse includes (i) information collection means for collecting, from a plurality of remote modules each at least to input or output a signal through channels connected to control target devices, module identification information for classification of the plurality of remote modules into a plurality of groups, (ii) group setting means for setting the plurality of groups using the module identification information collected by the information collection means, (iii) operation mode setting means for setting, for each of the plurality of groups, an operation mode of a remote module belonging to the group, and setting, for at least one group of the plurality of groups, an operation mode of a remote module belonging to the at least one group to a first operation mode for checking an operation of the remote module belonging to the at least one group, and (iv) display image forming means for forming an image displaying, for each of the plurality of groups, information about the remote module belonging to the group, the image displaying the operation of the remote module belonging to the at least one group and set to the first operation mode. 
     Advantageous Effects of Invention 
     In the above aspect of the present disclosure, the information collection means collects module identification information from the remote modules, and groups are set with the module identification information. The operation mode setting means sets the operation mode of remote modules belonging to the at least one group to a first operation mode. The display image forming means forms an image displaying the operation of the remote modules belonging to the at least one group set to the first operation mode. Thus, the operation mode for the remote modules can be set for each group, and the operation state or the operation result of the remote modules in each group can be collectively checked. This structure can thus simplify the work to start or change a production line. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates configuration of a PLC system according to Embodiment 1 of the present disclosure; 
         FIG. 2  illustrates configuration of a CPU module and a master module illustrated in  FIG. 1 ; 
         FIG. 3  illustrates configuration of a remote module illustrated in  FIG. 1 ; 
         FIG. 4  illustrates hardware configuration of a terminal illustrated in  FIG. 1 ; 
         FIG. 5  illustrates functional configuration of an engineering tool installed on the terminal illustrated in  FIG. 1 ; 
         FIG. 6  illustrates functional configuration of a start assist tool installed on the terminal illustrated in  FIG. 1 ; 
         FIG. 7  illustrates an example of group setting information stored in an auxiliary storage illustrated in  FIG. 4 ; 
         FIG. 8  illustrates an example of operation-mode setting information stored in the auxiliary storage illustrated in  FIG. 4 ; 
         FIG. 9  illustrates an example of a state diagram according to Embodiment 1; 
         FIG. 10  illustrates an example of an operation screen of the start assist tool illustrated in  FIG. 1 ; 
         FIG. 11  is a flowchart of operation performed by a remote module to switch the operation mode according to Embodiment 1; 
         FIG. 12  illustrates configuration of a PLC system according to Embodiment 2 of the present disclosure; 
         FIG. 13  illustrates configuration of a start assist tool in Embodiment 2; 
         FIG. 14  illustrates an example of buttons displayed on an operation screen according to Embodiment 2; 
         FIG. 15  illustrates an example of channel allocation information according to Embodiment 2; 
         FIG. 16  illustrates an example of data reception information according to Embodiment 2; and 
         FIG. 17  illustrates an example of data transmission information according to Embodiment 2. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A production assisting device and a production system according to one or more embodiments of the present disclosure are described in detail with reference to the drawings. 
     Embodiment 1 
     A production system according to the present embodiment produces products in a production line under control of a programmable logic controller (PLC). 
     As illustrated in  FIG. 1 , a PLC system  1  serving as a production system includes a terminal  100  that displays, sets, and updates various parameters for managing the operations of production line devices  500 , a central processing unit (CPU) module  200  that executes a control program  210 , a master module  300  that connects the CPU module  200  to a network, remote modules  400 A to  400 D that transmit and receive various types of data to and from the CPU module  200  through the master module  300  and that input and output current signals and voltage signals to and from the production line devices  500 , and the production line devices  500  that perform processing and sensing for production of the products. The terminal  100  is an example of a production assisting device. The master module  300  is an example of a host device that communicates with the remote modules  400 A to  400 D. 
     The remote modules  400 A to  400 D are also collectively referred to as remote modules  400 . 
     The terminal  100  includes a personal computer (PC), and serves as an engineering tool  110  or a start assist tool  120  in the PLC system  1  to provide the settings to the remote modules  400  through the CPU module  200  and the master module  300 . Each remote module  400  controls channels to which the corresponding production line devices  500  are connected in accordance with the acquired settings to control the production line devices  500 . 
     The terminal  100  and the CPU module  200  are connected with a network NWa to allow communication with each other. The CPU module  200  communicates with each remote module  400  not directly but through the master module  300 . The master module  300  and each remote module  400  are connected with a network NWb to allow communication with each other. The networks NWa and NWb may be any communication network either wired or wireless, such as the Internet, a local area network (LAN), or a virtual private network (VPN). 
     Terminal  100   
     The terminal  100  assists management of the production line devices  500  including monitoring, setting, and control of the production line devices  500 . The terminal  100  includes a general-purpose computer on which the engineering tool  110  and the start assist tool  120  are installed. 
     The engineering tool  110  specifies a remote module  400  with the operation mode set to a normal mode, and provides, to the remote module  400 , various types of module parameter information defining the operation of the remote module  400  through the CPU module  200  and the master module  300 . The specified remote module  400  controls channels to which the corresponding production line devices  500  are connected in accordance with the acquired settings to control the production line devices  500 . 
     The start assist tool  120  provides, to the remote module  400  with the operation mode set to a start assisting mode, various types of module parameter information defining the operation of the remote module  400  through the CPU module  200  and the master module  300 . The remote module  400  set to the start assisting mode controls the channels to which the corresponding production line devices  500  are connected in accordance with the provided settings to control the production line devices  500 . The details of the terminal  100 , the engineering tool  110 , and the start assist tool  120  are described later. 
     CPU Module  200  and Master Module  300   
     The example configurations of the CPU module  200  and the master module  300  are described with reference to  FIG. 2 . 
     The CPU module  200  includes a processor  20 , an external bus interface (external bus I/F)  21 , a PC interface (PC I/F)  22 , a storage  23 , a memory  24 , and an internal bus  25 . 
     The processor  20  executes the control program  210  stored in the memory  24 . The control program  210  controls the processor  20  and controls the operations of the master module  300  and the remote modules  400 . The external bus I/F  21  is connected to an external bus I/F  31  (described later) of the master module  300  with a communication path CP. The CPU module  200  receives and transmits data from and to the master module  300  through the external bus I/F  21 . 
     The terminal  100  is connected to the PC I/F  22  with the network NWa. 
     The storage  23  stores the control program  210  executable by the processor  20  and various types of data usable by the processor  20  to execute the control program  210 . An example of the storage  23  is a non-transitory recording medium or a nonvolatile semiconductor memory such as a read-only memory (ROM). 
     The memory  24  reads the control program  210  stored in the storage  23  upon the CPU module  200  is activated to allow the processor  20  to execute the control program  210 . An example of the memory  24  is a volatile or nonvolatile semiconductor memory such as a random-access memory (RAM). The internal bus  25  electrically connects the processor  20 , the external bus I/F  21 , the PC IX  22 , the storage  23 , and the memory  24  to each other. 
     Other than the capabilities dedicated to data transmission, the master module  300  has the configuration similar to the configuration of the CPU module  200 . The master module  300  includes a processor  30 , an external bus OF  31 , a storage  32 , a memory  33 , a network interface (network I/F)  34 , and an internal bus  35 . 
     Other than the capabilities to enable data transmission, the processor  30 , the storage  32 , and the memory  33  have the functions similar to the functions of the processor  20 , the storage  23 , and the memory  24 . The external bus I/F  31  is connected to the external bus I/F  21  of the CPU module  200  with the communication path CP. The external bus UFs  31  and  21  transmit and receive data to and from each other. The network I/F  34  is connected to each remote module  400  with the network NWb. The network I/F  34  and each remote module  400  can transmit and receive data to and from each other. The internal bus  35  electrically connects the processor  30 , the external bus I/F  31 , the storage  32 , the memory  33 , and the network I/F  34  to each other. 
     Remote Module  400   
     Again with reference to  FIG. 1 , each remote module  400  can change the operation mode for each group at any time by the settings of the start assist tool  120 . The operation mode includes a normal mode in which the engineering tool  110  performs individual settings and individual operational checks of module parameter information  122  about the remote module  400 , and a start assisting mode in which the start assist tool  120  performs collective settings and collective operational checks of module parameter information  126  about the remote module  400 . Examples of the module parameter information pieces  122  and  126  include the settings of the ranges of the current or voltage input into or output from the channels in each remote module  400  and the settings of approval/refusal indicating whether analogue/digital conversion is to be performed. The start assisting mode is an example of a first operation mode for collectively checking the operation of one or more remote modules  400  belonging to each group. The normal mode is an example of a second operation mode for individually checking the operation of each remote module  400 . The second operation mode is different from the first operation mode. 
     In  FIG. 1 , the remote modules  400 A and  400 C belong to a group GRa and operate in the start assisting mode. The remote modules  400 B and  400 D belong to a group GRb and operate in the normal mode. The groups GRa and GRb are examples of multiple groups into which the remote modules  400  are classified. 
     Production Line Devices  500   
     The production line devices  500  perform processing and sensing for production of the products. Each production line device  500  is connected to the corresponding channel in any of the remote modules  400  and operates under control of the remote module  400 . The production line devices  500  are examples of control target devices. 
       FIG. 3  is a block diagram of each remote module  400 . As illustrated, each remote module  400  includes a controller  410  for executing various programs, a network I/F  420  for receiving commands from the CPU module  200  through the master module  300 , a storage  430 , a memory  440 , a channel selector  450  for switching between channels CH, and an internal bus  45  for electrically connecting these components to each other. The remote module  400  at least inputs or outputs signals through the channels CH connected to the corresponding production line devices  500  serving as control target devices. 
     The controller  410  includes a processor and operates in either one of two operation modes including a normal mode  411  and a start assisting mode  412 . The controller  410  determines an effective operation mode with reference to an operation mode flag  441  stored in the memory  440 . The controller  410  sets the operation mode determined using the operation mode flag  441  as the operation mode of the controller  410 . 
     The network I/F  420  receives commands and data from the CPU module  200  through the master module  300 , provides the commands and data to the controller  410 , receives data from the controller  410 , and transmits the received data to the CPU module  200  through the master module  300 . 
     The storage  430  includes, for example, a non-transitory recording medium or a nonvolatile semiconductor memory such as a ROM, and stores a module number  431  indicating the group to which the remote module  400  belongs. The module number  431  is prestored in each remote module  400  by an assembled-product manufacturer that prepares components and provides assembled products. The module number  431  may be changed later by the start assist tool  120 . The module number  431  is an example of module identification information for classification of the multiple remote modules  400  into multiple groups. 
     The memory  440  includes, for example, a RAM and functions as a work area for the controller  410 . The memory  440  stores the operation mode flag  441  serving as operation mode information indicating a type of the current operation mode, output-value holding data  442  to hold output values, and an off-time output format  443  indicating format data at the stop of current and voltage outputs. The output-value holding data  442  and the off-time output format  443  are examples of information stored in the memory  440  in a remote module serving as an output module. 
     The channel selector  450  is connected to channels CH 1  to CH 4 . Based on an instruction from a program executed by the controller  410 , the channel selector  450  selects the channel CH through which the instruction data received from the CPU module  200  to the production line device  500  is transmitted. This enables data exchange between the controller  410  and the selected channel CH. The channel selector  450  may select, based on an instruction from the CPU module  200 , the channel through which the instruction data received from the CPU module  200  to the production line device  500  is transmitted. 
     The terminal  100  illustrated in  FIG. 1  includes a personal computer. As illustrated in  FIG. 4 , the terminal  100  includes, as hardware components, a CPU  101 , a ROM  102 , a RAM  103 , an auxiliary storage  104 , a display  105 , an inputter  106 , a communication interface (I/F)  107 , and a bus BL connecting these components to each other. 
     The CPU  101  reads various programs and data from the ROM  102  onto the RAM  103  to perform processing to control the entire terminal  100 . The CPU  101  performs the operations of the engineering tool  110  and the start assist tool  120 . 
     The ROM  102  stores various programs executable by the CPU  101 , initial data usable to execute these programs, and fixed data such as table data. The RAM  103  functions as a work memory for the CPU  101 . 
     The auxiliary storage  104  includes, for example, a hard disk device or a flash memory and stores various types of data. In the present embodiment, the storage area of the auxiliary storage  104  is divided into multiple partitions, and the engineering tool  110  and the start assist tool  120  store different types of information in different partitions. Instead, various types of information stored in the auxiliary storage  104  may be accessible by both the engineering tool  110  and the start assist tool  120 . 
     The display  105  displays images based on the control of the CPU  101 . The inputter  106  inputs instructions and data in accordance with the operation of a user. The communication I/F  107  communicates with the CPU module  200 . 
     As illustrated in  FIG. 5 , the CPU  101  loads various programs on the RAM  103  and executes the programs to function, in the engineering tool  110 , as an operation mode setter  111 , a network information setter  112 , and a transmission/reception setter  113 . 
     The operation mode setter  111  individually specifies each remote module  400  to set the operation mode flag  441  with the memory  440  and to set the module number  431  with the storage  430 . 
     The network information setter  112  individually specifies each remote module  400  to set the connection relationship for the remote modules  400 . To search for the connection state of each remote module  400 , for example, the network information setter  112  instructs the master module  300  to broadcast an address resolution protocol (ARP) request. Thus, the network information setter  112  acquires module information identifying the remote module  400  and network information  121  indicating the connection relationship between the master module  300  and the remote module  400 . For example, the network information setter  112  generates the module information about each remote module  400  and the network information  121  indicating that the remote modules  400 A and  400 B are connected to the master module  300  with the network NWb, that the remote module  400 C is subordinate to the remote module  400 A, and that the remote module  400 D is subordinate to the remote module  400 B, and stores the module information and the network information  121  in the auxiliary storage  104  to set the connection relationship for the remote modules  400 . The network information setter  112  sets the network address of each remote module  400 . 
     The transmission/reception setter  113  individually specifies each remote module  400  and sets module parameter information  122  about the remote module  400  stored in the auxiliary storage  104 . The module parameter information  122  includes default values of various parameters of each remote module  400 . 
     As illustrated in  FIG. 6 , the CPU  101  loads various programs on the RAM  103  and executes the programs to function, in the start assist tool  120 , as a group setter  114 , an operation mode setter  115 , a display image former  116 , a network information acquirer  117 , and a transmission/reception setter  118 . The auxiliary storage  104  stores group setting information  123 , operation-mode setting information  124 , network information  125 , and module parameter information  126 . 
     The group setter  114  classifies the multiple remote modules  400  into multiple groups. For example, the group setter  114  transmits a transmission request signal requesting each remote module  400  to transmit the module number  431  through the CPU module  200  and the master module  300  upon receiving a user operation, acquires the module number  431  from each remote module  400  in response to the request, and updates the group setting information  123  stored in the auxiliary storage  104 . At this time, the group setter  114  sets the remote modules  400  from which the same module number  431  is acquired to be in the same group. The group setter  114  is an example of information collection means and group setting means. The information collection means collects, from the multiple remote modules that each at least input or output signals through channels connected to the control target devices, module identification information for classification of the remote modules into multiple groups. The group setting means sets the multiple groups using the module identification information collected by the information collection means. The group setter  114  may be divided to separately implement the functions of collecting the module number  431  and setting the groups. 
     As illustrated in  FIG. 7 , the group setting information  123  includes a remote module address indicating the address of each remote module  400 , a model name of the remote module  400 , and identification information about the group to which the remote module  400  belongs in association with each other. The group setting information  123  illustrated in  FIG. 7  indicates that the remote modules  400 A and  400 C are assigned to a group I and the remote modules  400 B and  400 D are assigned to a group II in accordance with the configuration in  FIG. 1 . In the present embodiment, the remote modules  400  belonging to the group I are the same as the remote modules  400  belonging to the group GRa in  FIG. 1 , and the remote modules  400  belonging to the group II are the same as the remote modules  400  belonging to group GRb in  FIG. 1 . 
     The group setter  114  instructs the storage  430  in each remote module  400  to set the module number based on information input from the inputter  106 . In response to the instruction, the controller  410  in each remote module  400  updates the module number  431  stored in the storage  430 . 
     The operation mode setter  115  sets the operation mode for each group. The user operates the inputter  106  to input each group and the operation mode to be set for the remote modules  400  belonging to the group. As illustrated in  FIG. 8 , the operation mode setter  115  sets the input operation-mode setting information  124  with the auxiliary storage  104  and for the remote modules  400  belonging to the specified group. In the operation-mode setting information  124  illustrated in  FIG. 8 , the start assisting mode is set for the group I, and the normal mode is set for the group II in accordance with the configuration in  FIG. 1 . The operation mode setter  115  is an example of operation-mode setting means. The operation mode setting means sets, for each of multiple groups, the operation mode of the remote modules belonging to the group, and sets, for at least one group of the multiple groups, the operation mode of the remote modules belonging to the at least one group to a first operation mode for checking the operation of the remote modules. 
     The display image former  116  creates a state diagram based on the group setting information  123 , the operation-mode setting information  124 , and the network information  125  and displays the state diagram on the display  105 . The state diagram is an information diagram indicating the connection relationship between the master module  300  and each remote module  400 , the grouping of the remote modules, and the setting of the operation mode for each group. The state diagram shows the connection relationship indicated by the network information acquired by the network information acquirer  117  (described later), the group set by the group setter  114 , and the operation mode set by the operation mode setter  115  in association with one another. The display image former  116  forms an image that associates, for each remote module  400  for which the operation mode is set, (i) a result of an operation by each channel in the remote module  400  that is performed based on the module parameter information  126  and (ii) a corresponding channel number in the remote module  400 . This image can be displayed as a setting screen DS 1  (described later). The display image former  116  is an example of display image forming means. The display image forming means forms an image displaying, for each group, information about the remote modules belonging to the group and displaying the operation of the remote modules belonging to a group set to the first operation mode, and forms an image displaying the channels in each remote module belonging to the group and performance results that are results of performance in the first operation mode in association with each other. 
       FIG. 9  illustrates an example of a state diagram. In accordance with the configuration of  FIG. 1 , this state diagram indicates that i) the remote modules  400 A and  400 B are connected to the master module  300 , the remote module  400 C is subordinate to the remote module  400 A, and the remote module  400 D is subordinate to the remote module  400 B, ii) the remote modules  400 A and  400 C are assigned to the group I and the remote modules  400 B and  400 D are assigned to the group II, and iii) the group I is set to the start assisting mode and the group II is set to the normal mode. 
     The network information acquirer  117  receives network information from the engineering tool  110  through an engineering tool I/F  108  or a software interface between the engineering tool  110  and the start assist tool  120 , and registers the network information  125  in the auxiliary storage  104 . The network information  125  indicates the connection relationship between the remote modules  400  and the connection relationship between the master module  300  and each remote module  400 . In the configuration in  FIG. 1 , the network information  125  indicates that the remote modules  400 A and  400 B are connected to the master module  300 , that the remote module  400 C is subordinate to the remote module  400 A, and that the remote module  400 D is subordinate to the remote module  400 B. The network information acquirer  117  is an example of network information acquisition means. The network information acquisition means acquires network information indicating the connection relationship between the remote modules and between each remote module and the host device that communicates with the remote module. 
     The transmission/reception setter  118  sets, with each remote module  400 , the module parameter information  126  stored in the auxiliary storage  104  for each group. The transmission/reception setter  118  is an example of parameter setting means. The parameter setting means sets, with each remote module, module parameter information that defines the operation of the remote module. 
     The display  105  displays a start assisting setting screen. The inputter  106  inputs control information and communicates with the CPU module  200  through the communication I/F  107 . 
     The display image former  116  forms a screen illustrated in  FIG. 10  as an operation screen of the start assist tool  120  and displays the screen on the display  105 . 
     This operation screen includes an operation button set BT, a setting screen DS 1 , and a state display screen DS 2 . 
     The operation button set BT includes a module-information setting button BT 1 , a group setting button BT 2  including a group read button BT 21  and a group write button BT 22 , an operation-mode setting button BT 3 , a state-diagram creating button BT 4 , and a start/stop button BT 5 . 
     The module-information setting button BT 1  instructs the network information acquirer  117  to acquire module information about each remote module  400  set by the engineering tool  110  and network information indicating the connection relationship between the master module  300  and the remote module  400 . In response to the operation on this button, the network information acquirer  117  reads the network information  121  held by the engineering tool  110  through the engineering tool I/F  108  and stores the network information  121  as the network information  125  into the auxiliary storage  104 . 
     The group read button BT 21  instructs the group setter  114  to read and collect group information from each remote module  400 . In response to the operation on this button, the group setter  114  acquires the module number  431  set with the storage  430  in each remote module  400  through the CPU module  200  and the master module  300 , and stores the module number  431  into the auxiliary storage  104  as the group setting information  123  as illustrated in  FIG. 7 . The display image former  116  reflects the group setting information  123  on the setting screen DS 1  and the state display screen DS 2 . 
     The group write button BT 22  instructs the group setter  114  to write group information in each remote module  400  and to update the group configuration. When a user inputs the remote module  400  and the module number  431  of the remote module  400  through the inputter  106 , the group setter  114  communicates with the specified remote module  400  through the CPU module  200  and the master module  300 , writes a new module number  431  specified by the user on the module number  431  stored in the storage  430  in the remote module  400 , and updates the module number  431 . The group setter  114  also updates the group setting information  123  stored in the auxiliary storage  104 . 
     The operation-mode setting button BT 3  instructs the operation mode setter  115  to set the operation mode for each group. In response to the operation on this button, the operation mode setter  115  updates, for each group, the operation mode flag  441  registered in the memory  440  in each of the remote modules  400  belonging to the group. The user specifies the operation mode to be set for the group and the remote modules  400  belonging to the group through the inputter  106 . The operation mode setter  115  accesses each remote module  400  through the CPU module  200  and the master module  300  in accordance with the specified operation mode, and updates the operation mode flag  441 . The operation mode setter  115  updates the operation-mode setting information  124  stored in the auxiliary storage  104 . 
     The state-diagram creating button BT 4  instructs the display image former  116  to create a state diagram indicating the system configuration illustrated in  FIG. 9 . In response to this instruction, the display image former  116  creates the state diagram illustrated in  FIG. 9  and displays the state diagram on the display  105 . 
     The start/stop button BT 5  instructs to start and stop processing each remote module  400  set to the start assisting mode. The transmission/reception setter  118  starts, in response to the start instruction, setting the module parameter information  126  stored in the auxiliary storage  104  with each remote module  400  set to the start assisting mode, and stops the processing with the stop instruction. 
     The setting screen DS 1  includes module information identifying each remote module  400 , operation setting information indicating the operation settings of the remote module  400 , and current state information indicating the current input/output state of the remote module. The setting screen DS 1  is an example of an image formed by the display image former  116 . 
     The module information includes the remote module address and the model name of each remote module  400 . The operation setting information includes the operation mode set for the remote module  400 , the group to which the remote module  400  belongs, and the range setting indicating the range of the current value and the voltage value of each channel CH. The range setting on the setting screen DS 1  illustrated in  FIG. 10  simply illustrates the range of each channel CH for the current value. The range setting included in the operation setting information is displayed as module parameter information set with each remote module  400 . The current state information includes the current input/output amount of each channel CH in the remote module  400  and error details indicating an error code corresponding to an error. The input/output amount and the error details are displayed as performance results that are results of performance by the remote module  400  in the operation mode. 
     The state display screen DS 2  displays a state diagram indicating the system configuration illustrated in  FIG. 9 . 
     The processing performed by a user restarting each remote module  400  with the start assist tool  120  is described. 
     The user first operates the inputter  106  to input an instruction to display the operation screen illustrated in  FIG. 10  on the display  105 . 
     The display image former  116  forms the operation screen illustrated in  FIG. 10  based on the group setting information  123 , the operation-mode setting information  124 , the network information  125 , and the module parameter information  126  stored in the auxiliary storage  104 , and displays the operation screen on the display  105 . 
     The user operates the module-information setting button BT 1  on the setting screen DS 1  to cause the network information acquirer  117  to acquire the latest network information  121  held by the engineering tool  110 . The network information acquirer  117  updates the network information  125  stored in the auxiliary storage  104 , and the display image former  116  updates the display on the setting screen DS 1 . 
     The user then operates the group read button BT 21  to cause the group setter  114  to update the group setting information  123 . The group setter  114  updates the group setting information  123  stored in the auxiliary storage  104  based on the module number acquired from each remote module  400 . The display image former  116  updates the display on the setting screen DS 1 . 
     The user operates the operation-mode setting button BT 3  to add any change to the setting information displayed on the operation screen to edit the setting information. In response to this operation, the display image former  116  receives the operation on data on the operation screen through the inputter  106 . For example, the user sets the operation mode for each group. As appropriate, the module parameter information  126  including the setting of the current range for each channel CH is set with each remote module  400  set to the start assisting mode. The display image former  116  and the inputter  106  are examples of parameter setting means and editing means. The editing means receives editing of the module parameter information displayed on the setting screen. More specifically, the editing means is used by a user to edit the module parameter information. As appropriate, the parameter setting means sets, with the remote modules  400  set to the start assisting mode, the module parameter information edited with the editing means, that is, the module parameter information edited by the user through the editing means. Instead of the display image former  116 , the transmission/reception setter  118  may function as the parameter setting means. The display image former  116  and the transmission/reception setter  118  may integrally function as the parameter setting means. 
     As appropriate, the user operates the state-diagram creating button BT 4  to create a state diagram. In response to the operation on this button, the display image former  116  creates a state diagram based on the latest information and updates the state diagram on the operation screen. 
     When the start/stop button BT 5  is operated finally, the transmission/reception setter  118  transmits, to the corresponding remote module  400 , a setting value set on the setting screen DS 1  for the corresponding one of the remote modules  400  set to the start assisting mode. The controller  410  in each remote module  400  belonging to the group set to the start assisting mode sets the transmitted setting value with the corresponding portion. For example, when receiving setting information about the current range, the controller  410  sets the instructed current range with each channel CH. 
     The operation of the remote module  400  that has received an instruction from the start assist tool  120  is described with reference to  FIG. 11  illustrating a case in which notification of switching of the operation mode is sent. 
     The controller  410  in each remote module  400  periodically monitors the operation mode flag  441  (step S 101 ). 
     When the controller  410  determines that the operation mode flag  441  is changed (Yes in step S 101 ), the controller  410  switches the operation mode between the normal mode  411  and the start assisting mode  412  in accordance with the operation mode flag  441  (step S 102 ). When the operation mode flag  441  is thus updated, the remote module  400  sets the operation mode specified by the updated operation mode flag  441  as the operation mode of the remote module  400 . 
     For the remote module  400  serving as an output module, when the output values are suddenly turned off during the operation mode switching, the production line device  500  may perform an unintended operation. Thus, the controller  410  reads the off-time output format  443  stored in the memory  440  and determines whether the output format is a hold value (step S 103 ). 
     When a hold value is set as the off-time output format (Yes in step S 103 ), the controller  410  holds the preceding output value held as the output-value holding data  442  (step S 104 ). When a hold value is not set as the off-time output format (No in step S 103 ), the controller  410  sets an off value, such as an open state for breaking the electrical connection, as the output value (step S 105 ). 
     The remote module  400  to which the start assisting mode  412  is set in this manner as the operation mode of the controller  410  receives the setting and the update of the operation parameters for each group set by the start assist tool  120 , and performs the corresponding settings. For example, the remote module  400  sets the current range for each channel CH to the instructed value. 
     The remote module  400  to which the normal mode  411  is set as the operation mode is individually specified with the engineering tool  110  and receives the setting and the update of the module parameter information  122 . 
     In the present embodiment, the multiple remote modules  400  can be collectively divided into groups, and the operation mode for the remote modules  400  belonging to each of the groups can be changed by each group or the program and the parameters can be set by each group. The operations of the remote modules  400  can be collectively checked by displaying the operations of the remote modules  400  in accordance with the set parameter for each group. This structure can thus simplify the work to start or change the production line. 
     Embodiment 2 
     A production system according to Embodiment 2 of the present disclosure is described. A method according to the present embodiment includes virtually operating multiple remote modules set to the start assisting mode as a single module to control the remote modules by handling the remote modules as a single module. To start a large-scale production line including a large number of production lines, for example, multiple production lines each including multiple remote modules  400  that communicate with the CPU module  200  may be started one by one. When the control program  210  in the CPU module  200  connected to the multiple remote modules  400  to communicate with the remote modules  400  is changed, the CPU module  200  is to be rebooted. More specifically, a change in the number of remote modules  400  or a change in the devices to be used involves a change in the control program  210  and rebooting of the CPU module  200 . The CPU module  200  being rebooted can stop all the remote modules  400  in operation or cause other issues. In addition to the starting of a production line, replacement of the remote modules  400  or an increase or decrease in the number of remote modules  400  to be used in a later change in the production line can also cause similar issues. 
       FIG. 12  is a block diagram of the system according to the present embodiment. The basic configuration of the PLC system  1  according to the present embodiment is the same as the configuration in Embodiment 1. In this configuration, the remote modules  400  to which the start assisting mode is set are set as a virtual module  400 V that virtually operates as a single remote module with eight channels. The virtual module  400 V includes a representative module  400 A connected to the master module  300  and a subordinate module  400 C. When the start assist tool  120  sets the operation mode of the virtual module  400 V to the start assisting mode, each remote module  400  included in the virtual module  400 V operates as the representative module  400 A or the subordinate module  400 C. 
     With this operation, the start assist tool  120  sets the operation parameter with the representative module  400 A to cause channels CH 1  to CH 4  included in the representative module  400 A to appear as channels VCH 1  to VCH 4  in the virtual module  400 V, and sets the operation parameter with the subordinate module  400 C to cause channels CH 1  to CH 4  included in the subordinate module  400 C to appear as channels VCH 5  to VCH 8  in the virtual module  400 V. 
     The virtual module  400 V controls the production line devices  500  through the virtual channels VCH 1  to VCH 8 . 
     The CPU module  200  and the master module  300  handle the representative module  400 A and the subordinate module  400 C as a single remote module including eight virtual channels VCH 1  to VCH 8 . Thus, the start assist tool  120  sets one of the serially connected remote modules  400  as a representative module. The other remote modules  400  are automatically set as subordinate modules. In the example described below, the remote module  400 A is handled as a representative module. 
     The representative module  400 A determines whether the data received from the master module  300  is to be processed by the representative module  400 A or by the subordinate module  400 C. When determining that the data is to be processed by the representative module  400 A, the representative module  400 A processes the data. When determining that the data is to be processed by the subordinate module  400 C, the representative module  400 A converts the number of the virtual channel instructed by the master module  300  to the channel number of the subordinate module, and provides the data to the subordinate module  400 C. 
     More specifically, the virtual module  400 V in this example is an output module that outputs the current and the voltage to the production line devices  500  through the virtual channels VCH 1  to VCH 8 . The master module  300  transmits the output value data indicating the current and the voltage for the virtual channels VCH 1  to VCH 8  in the virtual module  400 V to the representative module  400 A. The representative module  400 A outputs the current and the voltage based on the output value data for the virtual channels VCH 1  to VCH 4  in the received output value data through the channels CH 1  to CH 4  in the representative module  400 A. 
     The representative module  400 A determines that the output value data indicating the current and the voltage for the virtual channels VCH 5  to VCH 8  is to be processed by the subordinate module  400 C. The representative module  400 A transmits the output value data for the virtual channels VCH 5  to VCH 8  to the subordinate module  400 C with information indicating that the virtual channels VCH 5  to VCH 8  correspond to the channels CH 1  to CH 4  in the subordinate module  400 C. The subordinate module  400 C outputs the current and the voltage based on the provided output value data for the virtual channels VCH 5  to VCH 8  from the channels CH 1  to CH 4  in the subordinate module  400 C. 
     When the virtual module  400 V serves as an input module, the subordinate module  400 C transmits input value data indicating the current and the voltage provided to the channels CH 1  to CH 4  in the subordinate module  400 C to the representative module  400 A together with the channel numbers. The representative module  400 A transmits, to the master module  300 , the input value data indicating the current and the voltage provided to the channels CH 1  to CH 4  in the representative module  400 A as input value data provided to the virtual channels VCH 1  to VCH 4 , and the data provided to the channels CH 1  to CH 4  in the subordinate module  400 C as input value data provided to the virtual channels VCH 5  to VCH 8 . 
       FIG. 13  is a block diagram of the start assist tool  120  used in Embodiment 2. As illustrated in  FIG. 13 , in addition to the configuration in  FIG. 6 , the auxiliary storage  104  in the start assist tool  120  according to Embodiment 2 stores channel allocation information  127 , data reception information  128 , and data transmission information  129 . The CPU  101  includes a virtual module setter  119 , a representative module setter  11 A, a channel allocator  11 B, a data transmission/reception information generator  11 C, and a virtual module setting reflector  11 D. 
     As illustrated in  FIG. 14 , in the present embodiment, the module-information setting button BT 1  on the setting screen includes a module-information read button BT 11  and a module-information write button BT 12 . The module-information read button BT 11  has the same function as the module-information setting button BT 1  in Embodiment 1, or specifically, the module-information read button BT 11  instructs to read the module information about each remote module  400  and the network information indicating the connection relationship between the master module  300  and each remote module  400 . The module-information write button BT 12  instructs the remote module  400  set by the start assist tool  120  to operate as a virtual module. 
     The virtual module setter  119  sets the groups divided in the above manner as the virtual module  400 V. In response to the operation on the module-information write button BT 12 , the operation parameter to be set for the virtual module  400 V set to the start assisting mode is set for the corresponding remote modules  400 . The remote modules  400  belonging to the group GRa are set as the virtual module  400 V. The virtual module setter  119  is an example of virtual module setting means. The virtual module setting means sets one or more groups of the groups set by the group setting means as a virtual module. Based on the network information  125 , the representative module setter  11 A automatically sets the remote module  400  connected to the master module  300  as a representative module and the remaining remote modules  400  as subordinate modules. The representative module setter  11 A is an example of representative module setting means. The representative module setting means sets one of the remote modules belonging to the virtual module as a representative module that transmits and receives data to and from a host device that communicates with the virtual module. The master module  300  corresponds to an example of the host device that communicates with the virtual module. 
     The channel allocator  11 B automatically generates the channel allocation information  127  from the group setting information  123  and the operation-mode setting information  124 .  FIG. 15  illustrates an example of the generated channel allocation information  127 . As illustrated, the channels in the virtual module  400 V are associated with the model name of each remote module included in the virtual module  400 V, the channel in the remote module, and the remote address of the remote module. Information specifying the representative module is also included. The channel allocator  11 B is an example of channel allocation means. The channel allocation means allocates channels in the virtual module to the channels in the remote module included in the virtual module. 
     The data transmission/reception information generator  11 C automatically generates the data reception information  128  and the data transmission information  129  to form the virtual module  400 V.  FIG. 16  illustrates an example of the data reception information  128 , and  FIG. 17  illustrates an example of the data transmission information  129 . 
     The virtual module setting reflector  11 D reflects, on the engineering tool  110 , the setting data that causes the remote module  400  to operate as the virtual module  400 V. More specifically, the virtual module setting reflector  11 D sends notification of the channel allocation information  127 , the module parameter information  126 , the data reception information  128 , and the data transmission information  129  from the engineering tool I/F  108 . This notification is transmitted to the engineering tool  110 . The virtual module setting reflector  11 D is an example of virtual module setting reflection means. The virtual module setting reflection means reflects, to the remote modules set to the second operation mode different from the first operation mode, the module parameter information and the channel allocation information indicating at least a correspondence relationship between the channels in the virtual module and the channels in the remote modules belonging to the group included in the virtual module. The engineering tool I/F  108  is an example of notification means. The notification means sends notification of the channel allocation information and the module parameter information to a tool that sets the module parameter information about the remote modules set to the second operation mode. 
     The remote module  400  set to the start assisting mode can be automatically set as the virtual module  400 V as described above. With this virtual module  400 V, the multiple remote modules  400  can be virtually handled as a single module. The CPU module  200  thus finds no change in the single remote module regardless of an increase or decrease in the number of remote modules  400  or replacement of the remote modules  400  in the virtual module  400 V. This eliminates a change in the control program and rebooting of the CPU module  200 . This structure can thus simplify the work to start or change the production line. 
     As described above, in the present embodiment, each group can be set to the start assisting mode to form a virtual module. This structure reduces and facilitates the process of forming a virtual module compared with the structure in which a user individually sets setting information for forming a virtual module with each remote module. 
     The start assist tool  120  sends notification of the channel allocation information  127 , the module parameter information  126 , the data reception information  128 , and the data transmission information  129  to the engineering tool  110 . The setting information about the virtual module usable by the start assist tool  120  is transferred to the engineering tool  110 . Thus, the virtual module can be easily handled using the engineering tool  110  after the production line starts the operation with the setting similar to the setting usable by the start assist tool  120  to start or change the production line. 
     In Embodiment 1 described above, the remote modules  400  are classified into two groups GRa and GRb, but may be classified into three or more groups. Each of the groups GRa and GRb may include one, three, or more remote modules  400 . Each group may include the same or a different number of remote modules  400 . When, for example, the remote modules  400  are classified into five groups, the operation mode setter  115  may set the first operation mode for three of the five groups, and the operation mode different from the first operation mode for the remaining two groups. In other words, the operation mode setter  115  can set the operation mode for the remote modules  400  belonging to at least one group. 
     In Embodiment 2 described above, the group GRa including two remote modules  400  is used as the virtual module  400 V, but the virtual module  400 V may include three or more remote modules  400 . The virtual module  400 V may include multiple groups. 
     The functions of the terminal  100  can be implementable by dedicated hardware or a common computer system. 
     For example, the program executed by the CPU  101  may be stored in a non-transitory computer-readable recording medium for distribution. The program is installed in a computer to provide a device that performs the above processing. Examples of such a non-transitory recording medium include a flexible disk, a compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), and a magneto-optical (MO) disk. 
     The program may be stored in a disk device included in a server on a communication network, typically the Internet, and may be, for example, superimposed on a carrier wave to be downloaded to a computer. 
     The processing described above may also be performed by the program being activated and executed while being transferred through a communication network. 
     The processing described above may also be performed by the program being entirely or partially executed on a server with a computer transmitting and receiving information about the processing through a communication network. 
     In the system with the above functions implementable partly by the operating system (OS) or through cooperation between the OS and applications, portions executable by applications other than the OS may be stored in a non-transitory recording medium that may be distributed or may be downloaded to the computer. 
     Means for implementing the functions of the terminal  100  is not limited to software. The functions may be partly or entirely implemented by dedicated hardware including circuits. 
     The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled. 
     INDUSTRIAL APPLICABILITY 
     As described above, a control method according to the present disclosure is applicable to a collective operation check to start a production line with multiple remote modules. 
     REFERENCE SIGNS LIST 
     
         
           1  PLC system 
           100  Terminal 
           101  CPU 
           102  ROM 
           103  RAM 
           104  Auxiliary storage 
           105  Display 
           106  Inputter 
           107  Communication I/F 
           108  Engineering tool I/F 
           110  Engineering tool 
           111  Operation mode setter 
           112  Network information setter 
           113  Transmission/reception setter 
           114  Group setter 
           115  Operation mode setter 
           116  Display image former 
           117  Network information acquirer 
           118  Transmission/reception setter 
           119  Virtual module setter 
           11 A Representative module setter 
           11 B Channel allocator 
           11 C Data transmission/reception information generator 
           11 D Virtual module setting reflector 
           121  Network information 
           122  Module parameter information 
           123  Group setting information 
           124  Operation-mode setting information 
           125  Network information 
           126  Module parameter information 
           127  Channel allocation information 
           128  Data reception information 
           129  Data transmission information 
           120  Start assist tool 
           200  CPU module 
           20  Processor 
           21  External bus I/F 
           22  PC I/F 
           23  Storage 
           24  Memory 
           25  Internal bus 
           210  Control program 
           300  Master module 
           30  Processor 
           31  External bus I/F 
           32  Storage 
           33  Memory 
           34  Network I/F 
           35  Internal bus 
           400 ,  400 A to  400 D Remote module 
           400 V Virtual module 
           410  Controller 
           411  Normal mode 
           412  Start assisting mode 
           420  Network I/F 
           430  Storage 
           431  Module number 
           440  Memory 
           441  Operation mode flag 
           442  Output-value holding data 
           443  Off-time output format 
           450  Channel selector 
           45  Internal bus 
           500  Production line device 
         BL Bus 
         BT Operation button set 
         BT 1  Module-information setting button 
         BT 11  Module-information read button 
         BT 12  Module-information write button 
         BT 2  Group setting button 
         BT 21  Group read button 
         BT 22  Group write button 
         BT 3  Operation-mode setting button 
         BT 4  State-diagram creating button 
         BT 5  Start/stop button 
         CP Communication path 
         CH, CH 1  to CH 4  Channel 
         DS 1  Setting screen 
         DS 2  State display screen 
         GRa, GRb Group 
         NWa, NWb Network 
         VCH Virtual channel