Patent Publication Number: US-2023144088-A1

Title: Display Unit

Description:
TECHNICAL FIELD 
     The present invention relates to a display unit. 
     BACKGROUND ART 
     Conventionally, an electric/heat energy network is known in which electric energy and heat energy are fused together (see, for example, Patent Document 1). The electric/heat energy network connects, for example, a cogeneration system, a renewable energy source, an electricity storage portion, a heat storage portion, a power supply network, a heat energy supply system, a power load, and a heat load. Optimization of an energy management of the electric/heat energy network is executed by a control unit (computer). 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: Japanese Patent No. 6423967 
     SUMMARY OF INVENTION 
     Technical Problem 
     The control unit for the energy management of the electric/heat energy network is equipped with an input unit and a display unit as man-machine interfaces. The display unit shows various entry screens, etc. 
     By the way, there may be a plurality of types of persons who give instructions to a control unit by using a screen of the display unit. The plurality of types of persons includes, for example, a person who is provided with a management system to manage energy (customer), an administrator of the management system, and a service man who is assigned by the administrator of the management system to maintain the system. So configuring that each of the types of persons can give an instruction to the control unit in the same way may cause an inconvenience. Further, by the way, there are many devices that are connected to the electrical and heat energy network. It is convenient if the state of these numerous devices can be easily grasped by the screen displayed by the display unit. 
     An object of the present invention is to provide a technology that can properly operate a management system that manages energy. Or, an object of the present invention is to provide a technology that can improve a convenience of a management system that manages energy. 
     Solution to Problem 
     An exemplary display unit of the present invention is a display unit of a management system that manages energy, wherein the display unit changes a display state of a screen that displays information about the management system, according to an operator of the screen. Another exemplary display unit of the present invention is a display unit of a management system that manages energy, wherein the management system displays a state monitoring screen that shows an operation state of a device of the management system. The state monitoring screen includes a device icon that shows the device. 
     Advantageous Effects of Invention 
     The exemplary invention allows for a proper operation of a management system that manages energy. The other exemplary invention allows for an improvement of a convenience of a management system that manages energy. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is an image diagram of a management system. 
         FIG.  2    is a block diagram of a system controller. 
         FIG.  3    is a schematic diagram showing a state of displaying a login screen on a screen of a display unit. 
         FIG.  4    is a schematic diagram showing a state of displaying a home screen on the screen of the display unit. 
         FIG.  5    is a schematic diagram showing a state of displaying a user management screen on the screen of the display unit. 
         FIG.  6    is a schematic diagram showing a state of an authority list screen included in the user management screen. 
         FIG.  7    is a schematic diagram showing a detailed example of an authority change operation area shown in  FIG.  6   . 
         FIG.  8    is a schematic diagram showing a state of displaying a device management screen on the screen of the display unit. 
         FIG.  9 A  is a schematic diagram showing an example of a screen displayed when a manual setting area is operated on the device management screen shown in  FIG.  8   . 
         FIG.  9 B  is a schematic diagram showing an example of a screen with a manual setting executed by using the manual setting area. 
         FIG.  10    is a schematic diagram for explaining a screen display seen when the manual setting area is operated during the manual setting. 
         FIG.  11    is a schematic diagram showing an example of a screen seen when a manual tab is operated. 
         FIG.  12    is a schematic diagram showing a device management screen which is displayed on the screen of the display unit and is different from that in  FIG.  8   . 
         FIG.  13    is a schematic diagram showing a state of displaying a state monitoring screen on the screen of the display unit. 
         FIG.  14    is an example of a case where multiple types of device icons are prepared for each device. 
         FIG.  15    is a diagram exemplifying the state of having changed the screen setting of the state monitoring screen shown in  FIG.  13   . 
         FIG.  16    is a schematic diagram showing a state monitoring screen of a modified example. 
         FIG.  17 A  is a diagram for explaining about an operation of a control button. 
         FIG.  17 B  is a diagram for explaining about the operation of the control button. 
         FIG.  17 C  is a diagram for explaining about the operation of the control button. 
         FIG.  18    is a diagram for explaining about the change in display mode of the control button. 
         FIG.  19 A  is a diagram for explaining that the device management screen is in conjunction with the operation of the control button. 
         FIG.  19 B  is a diagram for explaining that the device management screen is in conjunction with the operation of the control button. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following is a detailed description of an exemplary embodiment of the present invention with reference to the drawings. 
     &lt;1. Management System&gt; 
       FIG.  1    is an image diagram of a management system  100  according to an embodiment of the present invention. The management system  100  manages energy. That is, the management system  100  is an energy management system. In detail, the management system  100  manages electric energy and heat energy. The management system  100  is applied, for example, to a residential facility, an industrial facility, or a residential/industrial facility. 
     As shown in  FIG.  1   , the management system  100  includes a system controller  1 . The management system  100  manages electric energy and heat energy, centered on the system controller  1 . The management system  100  includes a facility that is so provided as to supply electric power (electricity-related facility) and a facility that is so provided as to supply at least one of hot heat and cold heat (heat-related facility). These facilities (devices) are controlled by the system controller  1 . 
     Note that the hot heat refers to heat that is hot, and the cold heat refers to heat that is cold. That is, when the heat is distinguished into hot heat and cold heat, the hot heat is hot heat and the cold heat is cold heat. For example, the hot heat is air with a higher temperature compared to the room temperature, and the cold heat is air with a lower temperature compared to the room temperature. The facilities shown in  FIG.  1    are merely an exemplification and may be changed to a configuration lacking any of the facilities shown in  FIG.  1    or to a configuration with an additional facility not shown in  FIG.  1   . 
     In the example shown in  FIG.  1   , the management system  100  includes a renewable energy generating unit  2  and a storage battery  3  each as the electricity-related facility described above. The renewable energy generating unit  2  and the storage battery  3  operate under the control of the system controller  1 . 
     The renewable energy generating unit  2  is a unit that generates electricity using renewable energy such as solar light, wind power, hydraulic power, and geothermal power, for example. The renewable energy generating unit  2  may be, for example, a photovoltaic generating unit or a wind power generating unit. To a power supply line of the management system  100 , the renewable energy generating unit  2  can supply the power obtained from the power generation. The storage battery  3  stores power generated by a power generation facility such as the renewable energy generating unit  2 , for example, and discharges the stored power as needed. That is, the storage battery  3  can supply power to the power supply line of the management system  100 . The storage battery  3  may be, for example, a lithium-ion battery. 
     The management system  100  is connected to a power system  10 . The power system  10  is a large commercial power system that supplies power to a power-receiving facility of the management system  100 . The management system  100  can purchase electricity from the power system  10  and receive the power supply. The system controller  1  is so provided as to control whether or not to receive power supply from the power system  10 . The system controller  1  may be so provided as to control whether or not power is supplied to the power system  10 . 
     In the example shown in  FIG.  1   , the management system  100  includes, as the heat-related facilities described above, a boiler  4 , a heat pump  5 , and a hot water tank  6 . The boiler  4 , the heat pump  5 , and the hot water tank  6  operate under the control of the system controller  1 . 
     To a heat supply line of the management system  100 , the boiler  4  can supply the steam or hot water&#39;s heat energy obtained by combustion of gas or other fuels. Th heat pump  5  operates an engine fueled by a gas fuel or the like thereby to drive a compression unit for compressing a refrigerant, providing temperature control by the condensation or evaporation heat of the refrigerant. Here, the temperature control is, for example, the temperature control of the air in a room, etc. when the heat pump  5  is applied to an air conditioner, or the temperature control of a chiller circulating liquid when the heat pump  5  is applied to a chiller. The circulating liquid is typically water as an exemplification. The heat pump  5  can perform cooling operation to cool the temperature-controlled object and heating operation to heat the temperature-controlled object. That is, the heat pump  5  can switch between hot heat and cold heat, and supply the hot heat or the cold heat to the heat supply line of the management system  100 . The hot water tank  6  is connected to the boiler  4 , etc. and is capable of exchanging the water medium in the tank to hot water and storing hot heat. The heat stored in the hot water tank  6  can be supplied to the heat supply line of the management system  100 . 
     In the example shown in  FIG.  1   , the management system  100  includes a cogeneration system  7  as a facility that is commonly used for the electricity-related facility and heat-related facility described above. The cogeneration system  7  operate under the control of the system controller  1 . The cogeneration system  7  uses gas fuel or the like thereby to drive the engine, and generates electricity using a generator that is operated by the driving of the engine. The power generated by the generator can be supplied to the power supply line of the management system  100 . To the heat supply line of the management system  100 , the cogeneration system  7  can supply the steam or hot water&#39;s heat energy obtained by a waste heat recovery boiler that uses the heat (waste heat) generated by the engine. 
     To a power load included in the management system  100 , power is supplied from the renewable energy generating unit  2 , the storage battery  3 , the power system  10 , or the cogeneration system  7 . The power load includes, for example, an electric light and various types of electric devices. To a heat load included in the management system  100 , the hot heat or cold heat from the boiler  4 , the heat pump  5 , the hot water tank  6 , or the cogeneration system  7  is supplied. The heat load includes, for example, a cooling unit, a heating unit, a refrigerator, a freezer, a hot water tank, etc. 
     &lt;2. System Controller&gt; 
       FIG.  2    is a block diagram of the system controller  1  according to the embodiment of the present invention. As shown in  FIG.  2   , the system controller  1  has a control unit  11 , an input unit  12 , and a display unit  13 . That is, the management system  100  has the display unit  13 . The management system  100  further has the control unit  11  and the input unit  12 . 
     The control unit  11  controls the entire management system  100 . The control unit  11  is so configured as to include an arithmetic operation integrated circuit such as a CPU, a RAM (Random Access Memory), a ROM (Read Only Memory), etc. With the arithmetic operation integrated circuit such as the CPU executing an arithmetic processing that accords to a computer program stored in a memory such as ROM, the control unit  11  executes various functions. 
     The input unit  12  is so provided as to allow inputting of a command to the control unit  11 . The input unit  12  includes at least one of a touch screen, a keyboard, a mouse, a touch pad, a button, and a rotary knob, for example. For example, when the input unit  12  is the touch screen, the input unit  12  and the display unit  13  may be an integrated unit. The integrated unit may also include the control unit  11 . 
     The display unit  13 , under the control of the control unit  11 , displays a screen that displays various information related to the management system  100 , and an entry screen for giving the command to the control unit  11 . The display unit  13  is composed of, for example, a liquid crystal panel or an organic EL panel. The display unit  13  may include the touch screen, in which case the display unit  13  doubles as the input unit  12 , as described above. The display unit  13  may be placed near or remote to the various devices possessed by the management system  100 . That is, the configuration of the present embodiment includes the display unit  13  being remote to each device. 
     &lt;3. Screen Display of Display Unit&gt; 
     Next, a display on the screen of the display unit  13  will be described in detail. 
     (3-1. Overview of Screen Display) 
       FIG.  3    shows a schematic diagram showing a state of displaying a login screen  131  on a screen  130  of the display unit  13 . A person (user) who attempts to access the management system  100  is first required to enter predetermined information on the login screen  131 . That is, the screen for displaying various information related to the management system  100 , the entry screen for entering the command to the control unit  11 , and the like cannot be viewed without the user entering necessary information in the login screen  131 . 
     In the present embodiment, as shown in  FIG.  3   , the login screen  131  has a login information entry area  1311 . The login information entry area  1311  has a user name entry area  1311   a  for entering the user name, a password entry area  1311   b  for entering a password preliminarily associated with the user name, and a login button  1311   c.  That is, on the login screen  131 , the user is required to enter the user name and the password. 
     The user name and the password are entered using, for example, the keyboard or the touch screen. In a configuration using the touch screen or mouse for entering, it may be so configured that the entering is executed using a software keyboard (virtual keyboard) that appears within the login screen  131 . The software keyboard may be, for example, so configured as to appear in the login screen  131  when the user touches or clicks the user name entry area  1311   a  or the password entry area  1311   b.  A similar software keyboard may be used to enter letters and numbers on any type of screen other than the login screen  131 . 
     In the present embodiment, the top end portion of the login screen  131  has a header area  200  that extends in the right/left direction of the screen  130 . In addition, the bottom end portion of the login screen  131  has a footer area  300  that extends in the right/left direction of the screen  130 . The header area  200  and the footer area  300  are properly displayed on any type of screen other than the login screen  131 . The header area  200  displays, for example, a company logo, a menu related to the screen display, and the like. The footer area  300  displays, for example, time, a user name allowed to log in, and the like. 
     Operating the login button  1311   c  by touch or the like after the user name and the password are entered displays a home screen  132 . When at least one of the user name and the password is improper, an error message is displayed on the login screen  131 , failing to display the home screen  132 . 
       FIG.  4    is a schematic diagram showing a state of displaying the home screen  132  on the screen  130  of the display unit  13 . In the present embodiment, the home screen  132  is a screen designed to allow the supply and demand of the electric energy and heat energy in the management system  100  to be viewed at a glance. In the example shown in  FIG.  4   , the home screen  132  has the header area  200 . The header area  200  includes a menu area  400  that shows the type of screen display that can be selected. In the present embodiment, the menu area  400  includes a home button  401 , a status monitoring button  402 , a graph button  403 , a device management button  404 , and an operation setting button  405 . The touch screen, mouse, or keyboard, for example, may be used to operate each of the buttons  401  to  405 . 
     In the example shown in  FIG.  4   , the home screen  132  is in a selected state, so a selection display is provided to show the above selected state. In detail, a frame surrounding the home button  401  is displayed as the selection display. However, the selection display is not limited to the frame surrounding the button, but may be configured otherwise, such as a configuration of making a button different in color from another button, or a configuration of making a button different in hatching from another button. 
     Selecting the status monitoring button  402  displays a status monitoring screen. The status monitoring screen displays details of an operating status of each device included in the management system  100 . Each device includes the heat and electric devices. The heat device includes, for example, the heat-related facility described above (including a facility that is used also for the electricity-related facility) and the heat load (air conditioning facility, footbath facility, etc.). The electric device includes, for example, the electricity-related facility (including a facility that is used also for heat-related facility) and the power load described above. 
     Selecting the graph button  403  displays a graph screen. The graph screen displays, for example, a graph or the like showing the shift in magnitude of the hourly heat and power loads for one day as well as a breakdown of each device&#39;s output relative to the load. 
     Selecting the device management button  404  displays a device management screen. The device management screen displays device management information including input/output information of each device. 
     Selecting the operation setting button  405  displays an operation setting screen. The operation setting screen includes an entry screen for entering information related to the operation of the management system  100 . The information related to the operation includes information about the control method of the management system  100 . In the present embodiment, it is so configured that the operation setting screen can select whether an optimization control and a demand control are enabled or disabled. 
     The optimization control is a control method in which control is executed according to an optimization target selected by the user (typical example is a customer) using the management system  100 . The optimization targets include, for example, the cost priority which prioritizes the reduction of various fees borne by the user, the carbon dioxide emission priority which prioritizes the reduction of carbon dioxide emission generated by the device operation, and the primary energy consumption priority which prioritizes the reduction of primary energy consumption required for the device operation. In the present embodiment, the user can select any one of these three optimization targets. The user, when selecting the cost priority, executes the operation control prioritizing the cost reduction, assuming that the optimization control is set to be enabled. The user, when selecting the carbon dioxide emission priority, executes the operation control prioritizing the reduction of carbon dioxide emission, assuming that the optimization control is set to be enabled. The user, when selecting the primary energy consumption priority, executes the operation control prioritizing the reduction of primary energy consumption, assuming that the optimization control is set to be enabled. 
     The demand control is a control method that so controls the device included in the management system  100  that the power received from the power system  10  does not exceed the target demand value. The target demand value is set at the contract power or less. When the optimization control and the demand control are set to be enabled, in principle, the management system  100  operates by the optimization control, and when the power received approaches the target demand value, the management system  100  switches to the demand control. 
     As can be seen from the above description, the display unit  13  can display the information, which is managed by the management system  100 , by switching to multiple types of screens. In the example shown in  FIG.  4   , it is possible to switch to at least five different screens including the home screen, the status monitoring screen, the graph screen, the device management screen, and the operation setting screen. However, these screen displays are merely an exemplification, and the types of screens that can be displayed by the display unit  13  may be changed as needed. 
     In the example shown in  FIG.  4   , the menu area  400  includes a feed button  406 . Operating the feed button  406  by touch or the like switches the type of screen type selection button displayed in the menu area  400 . That is, the example shown in  FIG.  4    can display any screen other than the five types including the home screen, the status monitoring screen, the graph screen, the device management screen, and the operation setting screen. 
     Examples of screens other than the five types described above include a user management screen for entering user information, and a screen setting screen for setting a screen-related condition. 
     In the example shown in  FIG.  4   , the home screen  132  has the footer area  300 . The footer area  300  includes an icon area  301  showing the user name and a time information area  302  including date and time. In the present embodiment, operating the icon area  301  by touch or the like can execute logout. As a preferred configuration, operating the icon area  301  displays a confirmation screen on the screen in a pop-up manner to confirm whether or not the logout may be executed, and the confirmation screen allowing the logout executes the logout. 
     In the present embodiment, as a preferred form, the various screens that can be selected by the menu area  400 , such as the home screen  132 , further includes a control state display area  500  that shows the control state of the management system  100 . With the above configuration; on the screen capable of grasping various types of information, the user can simultaneously obtain information on the control state of the management system  100 . That is, user convenience can be improved. 
     In the embodiment, the control state display area  500  is included in the header area  200 . In detail, the control state display area  500  is placed to the right of the menu area  400 . However, the position of the control state display area  500  may be changed as needed. In the example shown in  FIG.  4   , “Optimization” is displayed in the control state display area  500 . This shows that the management system  100  is being operated under the optimization control described above. In addition to this, “Demand Control”, “Stopped”, etc. are displayed in the control state display area  500 , for example. 
     (3-2. User Management Screen) 
       FIG.  5    is a schematic diagram showing a state of displaying a user management screen  133  on the screen  130  of the display unit  13 . By touch or the like, operating a user management button  407  displayed in the menu area  400  can select the user management screen  133 . 
     In detail, the user management screen  133  includes a sub-menu area  410 . The user management screen  133  displays a content that accords to a button selected from buttons  411   a,    411   b,  and  411   c  displayed in the sub-menu area  410 . In the present embodiment, the buttons displayed in the sub-menu area  410  of the user management screen  133  include a personal setting button  411   a,  a user management list button  411   b,  and an authority list button  411   c.    FIG.  5    shows the screen seen when the user management list button  411   b  is selected. 
     In the present embodiment, when any screen other than the user management screen  133  (for example, the home screen  132 ) is displayed, selecting the user management button  407  automatically selects a specific button that is any of the multiple buttons  411   a  to  411   c  displayed in the sub-menu area  410 , and displays the screen that corresponds to the selected button. For example, when the personal setting button  411   a  is designated as the specific button, selecting the user management button  407  automatically selects the personal setting button  411   a,  displaying a personal setting screen which is a screen for executing a personal setting. In the present embodiment, such a method is also used for any other screen having the sub-menu area  410 . 
     The list displayed on the user management screen  133  shown in  FIG.  5    is a list of users (user names) registered in the management system  100 . For each user name, an authority group and a display language are shown. The display language is a language set in the personal setting screen displayed by the operation of the personal setting button  411   a.  The authority group is a group divided according to the different authorities granted to the management system  100 . A specific example of the authority granted to the management system  100  is access authority. 
     In the present embodiment, the authority groups include four types of groups: “Administrator”, “Service man”, “General,” and “Guest”. “Administrator”, “Service man”, “General”, and “Guest” in that order have fewer authorities. That is, the “Administrator” has the most authorities and the “Guest” has the least authorities. “Administrator” is a group to which any person who manages the management system  100  belongs. “Service man” is a group to which any person who is assigned by the administrator to maintain the management system  100  belongs. “General” is a group to which any customer who has signed a contract to use the management system  100  belongs. “Guest” is a group to which any person, etc. who is trying out the management system  100  as part of a demonstration belongs, for example. The type and number of authority groups may be properly changed. 
     To which authority group each user belongs is determined by the administrator, for example, and cannot be freely determined by each user. The authority of the person accessing the management system  100  is determined by the user name entered on the login screen  131 . For example, the “Enable”, “Edit”, and “Delete” fields shown in  FIG.  5    are displayed in different modes depending on the authority group to which the logged-in user (user name) belongs. A button is displayed for an authorized item. In the example shown in  FIG.  5   , the logged-in user is authorized to make an edit to the registered content of the user belonging to Service man and General. For example, the logged-in user cannot execute “Enable”, “Edit”, and “Delete” of the logged-in user himself/herself, and of any user belonging to a group higher in authority level than the logged-in user himself/herself. 
     Note that “Enable” refers to the authority to admit each user as a registrant of the management system  100 . When a button is displayed in the “Enable” field, the user operating while viewing that screen can admit the person, whose button is displayed, as a registrant of the management system  100 . “Delete” refers to the authority to delete the user, who was once registered, from the registrant. When the button is displayed in the “Delete” field, the user operating while viewing that screen can delete the person, whose button is displayed, from the registrants in the management system  100 . 
       FIG.  6    is a schematic diagram showing a state of an authority list screen  133   a  included in the user management screen  133 . The authority list screen  133   a  is displayed when the authority list button  411   c  is operated by touch or the like on the screen shown in  FIG.  5   , for example. The authority list screen  133   a  shows the current authority status regarding the authority group that can edit the authority. 
     In the list shown in  FIG.  6   , “Screen” shows the name (type name) of the various screens displayed on the screen  130  of the display unit  13 . In the example shown in  FIG.  6   , the authority group that can edit the authority is the Service man and General. The authority statuses on various screens are shown for both groups of Service man and General. In the example shown in  FIG.  6   , a blank portion shows that the authority cannot be changed. In the screen displayed in  FIG.  6   , the authority can be changed for both Service man and General for a cost-effectiveness screen included in a graph screen. Due to this, an authority change operation area  1331  to allow for an authority change operation is shown in the appropriate portion. 
       FIG.  7    is a schematic diagram showing a detailed example of the authority change operation area  1331  shown in  FIG.  6   . Operating, by touch or the like, a selection button  1331   a  in the authority change operation area  1331  displays, in the authority list screen  133   a,  a selection item list shown in  FIG.  7   . In the present example, one item can be selected from “No Access”, “View Only”, “Partial Edit”, and “Full Access”. The number and type of items that can be changed in the authority may be properly changed. The number and type of items whose authorities can be changed may differ depending on the type of screen (screen name). Further, different authority groups may have different items for which the authority can be changed. 
     “No Access” shows that the target screen (in the example shown in  FIG.  6   , the cost-effectiveness screen) cannot be viewed. Since the target screen cannot be viewed, all of operation items that can be operated when the target screen is displayed are rejected. The “View Only” shows that only viewing of the target screen is allowed, and all of the operation items that can be operated on that screen are rejected. In the View Only screen all operation areas (buttons, etc.) that are displayed when the authority is granted are prevented from being displayed, or are grayed out showing that functions have been disabled as operation areas, for example. 
     “Partial Edit” shows that viewing of the target screen is permitted, and the operation of some of the operation items that can be operated on that screen is permitted. In the Partial Edit screen, only the operation area (button, etc.) for the authorized item is displayed, for example, and the operation area for the unauthorized item is not displayed. As another example, all operation areas are displayed, but the operation area for the unauthorized item is grayed out. “Full Accessible” shows that the user is allowed to view the target screen and to operate all of the operation items that can be operated on that screen. 
     The person performing the operation while viewing the authority list screen  133   a  selects a selectable authority item, and can change the authority by touching an application button  1332  displayed on the authority list screen  133   a.  Any person, who is not authorized to change the authority, displaying the authority list screen  133   a  disenables the application button  1332 , for example, failing to change the authority. 
     As can be seen from the above, the display unit  13  changes the display state of the screen displaying the information about the management system  100 , according to the type of the operator who uses the screen thereby to execute the operation. This configuration prevents any improper operation by a person who fails to have sufficient knowledge about the management system  100 . That is, the management system  100  can be properly operated. 
     In the present embodiment, the type of operator is determined based on the input information entered on the login screen  131 . In detail, the type of operator is determined by the user name entered on the login screen  131 . This determination is made by the control unit  11 , for example. However, the determination of the operator type may be performed by an information processing unit (computer unit) that is provided separately from the control unit  11 . 
     (3-3. Device Management Screen) 
       FIG.  8    is a schematic diagram showing a state of displaying a device management screen  134  on the screen  130  of the display unit  13 . By touch or the like, operating the device management button  404  displayed in the menu area  400  can select the device management screen  134 .  FIG.  8    also exemplifies a screen displayed when the user name whose authority group belongs to the service man is entered on the login screen  131 . This is also the case in  FIGS.  9 A,  9 B,  10 , and  11   , described below. 
     In detail, the device management screen  134  includes a sub-menu area  410 . The device management screen  134  displays the content that accords to buttons  411   d,    411   e  selected in the sub-menu area  410 . Buttons displayed in the sub-menu area  410  of the device management screen  134  include a device detail button  411   d  and a maintenance button  411   e.    FIG.  8    shows the state in which the device detail button  411   d  is selected. 
     As shown in  FIG.  8   , selecting the device detail button  411   d  displays input and output information of each device of the management system  100 . That is, the device management screen  134  displays device management information including the input and output information of the device of the management system  100 . The devices of the management system  100  include the electricity-related facility and heat-related facility (including a device that is used for both) described above, for example. Specifically, the renewable energy generating unit  2 , the storage battery  3 , the boiler  4 , the heat pump  5 , the hot water tank  6 , and the cogeneration system  7 , for example, are included in the devices of the management system  100 . In the present embodiment, the management system  100  has more than one device. 
     “Management Address” displayed on the device management screen  134  is an address defined in the control unit  11 , and, in the present embodiment, includes both a control address and a non-control address. “Type” shows input or output classification. “DI” means digital input. “DO” means digital output. “AI” means analog input. “AO” means analog output. “Item Name” is a specific name of the object whose input or output is managed. “Cogeneration” in  FIG.  8    denotes cogeneration system. 
     “Manual Setting Underway” displayed on the device management screen  134  displays information related to the manual setting of the input or output information for each item managed by using the management address. That is, the device management screen  134  has a manual setting information display area  1340 . In the present embodiment, the information displayed in the manual setting information display area  1340  includes the display of the operation button that enables the manual setting. The operation button is operated by touch or the like. In other words, the device management screen  134  has a manual setting area  1341  that allows for the manual setting of the input or output information of the device of the management system  100 . In the present embodiment, the manual setting area  1341  is an operation button. Details of the manual setting area  1341  are described below. 
     The “Current State” displayed on the device management screen  134  shows the current state of the input or output of each item managed by using the management address. That is, the device management screen  134  further has a current state display area  1342  that displays the current state of the input or output of the device of the management system  100 . The display of the current state may be a word or a numeral. 
     The “Control Reason” displayed on the device management screen  134  shows the control-related reason for the current state of the input or output of each item managed by using the management address. That is, the device management screen  134  further has a control reason display area  1343  that displays the control reason for the current state of the input or output of the device. 
     The display showing the control reason includes “Optimization” showing that the current state is derived from optimization control, and “Manual” showing that the current state is derived from the manual setting, for example. The control reason may be configured to be displayed for all or for some of items managed by using the management address. For example, the control reason may be so configured as not to be displayed (as to be left blank) for the non-control address out of the management addresses. 
     In the example shown in  FIG.  8   , the upper left side of the table displaying the input and output information of each device has a device selection tab  1347  for selecting the device for displaying the input and output information. In the present example, the device selection tab  1347  includes, as an example, “Overall”, “CP”, “Boiler”, and “Other”. In the example shown in  FIG.  8   , “Entire” is selected for the device selection tab  1347 , showing the input and output information about the entire device. Selecting the symbol “CP” meaning the cogeneration system  7  as the device selection tab  1347  displays the input and output information about the cogeneration system  7 . As the device selection tab  1347 , selecting “Boiler” which is a symbol meaning the boiler  4  displays the input and output information about the boiler  4 . Selecting “Other” as the device selection tab  1347  displays the input and output information on the device excluding the cogeneration system  7  and boiler  4 . 
     That is, for each device, the device management screen  134  can be switched, making it possible to display the unit management information. The type and number of devices included in the device selection tab  1347  may be properly changed. Placement of the device selection tab  1347  may also be properly changed. 
     Next, the manual setting area  1341 , which is configured as an operation button, is described in detail. As described below, the manual setting area  1341  is, as the case may be, not displayed.  FIG.  9 A  is a schematic diagram showing an example of a screen displayed when the manual setting area  1341  is operated on the device management screen  134  shown in  FIG.  8   .  FIG.  9 A  shows, in detail, an example of the screen seen when the manual setting area  1341  corresponding to the item name “Cogeneration Power Upper Limit Command” is operated by touch or the like. 
     Operating the manual setting area  1341  displays a first pop-up screen  1344  that allows for changing the input or output information of the corresponding item. The example shown in  FIG.  9 A  displays the first pop-up screen  1344  that allows for changing the power upper limit command (output information). Into an input area  1344   a  of the power upper limit command on the first pop-up screen  1344 , 10.0 kw is entered. That is, the operation to change the output value from the current state (power upper limit command 0 kw) is done. For example, a software keyboard including a numeric keypad may be used to input the power upper limit command. 
     In the state shown in  FIG.  9 A , operating an OK button  1344   b  in the first pop-up screen  1344  by touch or the like executes the change of the power upper limit command. Also, operating a CANCEL button  1344   c  in the first pop-up screen  1344  by touch or the like deletes the first pop-up screen  1344  thereafter to return to the screen shown in  FIG.  8   , without executing the change of the power upper limit command. 
       FIG.  9 B  is a schematic diagram showing an example of a screen with the manual setting executed by using the manual setting area  1341 .  FIG.  9 B  shows, in detail, an example of the screen seen when the OK button  1344   b  is operated by touch or the like in  FIG.  9 A . Operating the OK button  1344   b  deletes the first pop-up screen  1344 , showing, in the manual setting information display area  1340 , a display notifying that the manual setting have been executed. In  FIG.  9 B , a text “Manual Setting Underway” appears overlapping the manual setting area  1341 , as an example. That is, the user who has seen the manual setting area  1341  displaying the overlapping text “Manual Setting Underway”, can recognize that a corresponding item is being manually set. Since it is sufficient to notify the user that the manual setting is being executed, it may be so configured that the color of the manual setting area  1341  is changed, instead of overlapping the text “Manual Setting Underway”, for example. 
     In the example shown in  FIG.  9 B , the manual setting changed the power upper limit command of the cogeneration system  7  to 10.0 kw, therefore having automatically changed the input value of the generated power of the cogeneration system  7  (item name: cogeneration power) from 0 kw shown in  FIGS.  8    to 10 kw. 
       FIG.  10    is a schematic diagram for explaining a screen display seen when the manual setting area  1341  is operated during the manual setting. As shown in  FIG.  10   , operating the manual setting area  1341 , in which “Manual Setting Underway” is displayed overlapping, by touch or the like displays a second pop-up screen  1345 . The second pop-up screen  1345 , like the first pop-up screen  1344 , includes an input area  1345   a  where a value can be entered, an OK button  1345   b,  and a CANCEL button  1345   c.  Entering the value in the input area  1345   a  thereafter to operate the OK button  1345   b  by touch or the like can further change the value that was manually set previously. 
     Unlike the first pop-up screen  1344 , the second pop-up screen  1345  includes a RESET button  1345   d.  Operating the RESET button  1345   d  by touch or the like can return to the state before executing the manual setting. Operating the RESET button  1345   d  by touch or the like in the screen shown in  FIG.  10    returns to the screen shown in  FIG.  8   . Using the RESET button  1345   d  can easily return to the state before executing the manual setting, therefore making the RESET button  1345   d  a function convenient for the user. 
     Further, in the present embodiment, as shown in  FIG.  8   , for example, the upper right side of the table displaying the input and output information of each device is provided with a manual tab  1346  to display the input and output information only on the manually set item.  FIG.  11    is a schematic diagram showing an example of the screen seen when the manual tab  1346  is operated. As shown in  FIG.  11   , operating the manual tab  1346  by touch or the like display, only for the manually set item currently, a screen showing the current state of the input or output. In the example shown in  FIG.  11   , only one item is being manually set currently, so the current state, etc., is displayed for that item only. When there are multiple items for which the manual setting is being made currently, current states, etc. of all of the multiple items will be displayed. 
     That is, in the present embodiment, the device management screen  134  further has an operation area  1346  that displays the device management information only for the item that has been set by using the manual setting area  1341 . Placement of the manual tabs  1346  may be properly changed. 
       FIG.  12    is a schematic diagram showing a device management screen  134 A which is displayed on the screen  130  of the display unit  13  and is different from the counterpart in  FIG.  8   .  FIG.  12    exemplifies the screen displayed when the user name whose authority group belongs to General is entered on the login screen  131 . As described above,  FIG.  8    is the example of the screen displayed when the user name whose authority group belongs to the service man is entered on the login screen  131 . That is, the types of persons who use the device management screen thereby to execute the operation are different between  FIG.  12    and  FIG.  8   . Like  FIG.  8   ,  FIG.  12    is the screen seen when the device detail button  411 d is selected. 
     On the device management screen  134 A shown in  FIG.  12   , only the device detail button  411   d  is displayed in the sub-menu area  410 . This is different from the fact that, in the device management screen  134  shown in  FIG.  8   , the device detail button  411   d  and the maintenance button  411   e  are displayed in the sub-menu area  410 . The maintenance button  411   e  is for maintenance of the device of the management system  100 , and therefore is not necessarily needed for the user of General (customer). Due to this, it is so configured that the maintenance button  411   e  is not displayed when the login is executed by the user name whose authority group belongs to General. 
     Note that the configuration here is such that the maintenance button  411   e  is not displayed for the unauthorized user, but this is merely an exemplification. It may be so configured that the maintenance button  411   e  is displayed even for the unauthorized user, and the user&#39;s operation on the maintenance button  411   e  is disabled. In this case, it may be so configured that the maintenance button  411   e  is grayed out so as to make the user aware that the operation is disabled, for example. 
     On the device management screen  134 A shown in  FIG.  12   ; for some items managed by the management address, the manual setting area  1341 , which is configured as the operation button, is not displayed in the manual setting information display area  1340 . Specifically, for the item names “Cogeneration Power” and “Cogeneration Power Upper Limit Command”, the manual setting area  1341  is not displayed in the manual setting information display area  1340 . That is, when the user logs in with the user name whose authority group belongs to General, the manual setting cannot be made for some items for which the service man can make the manual setting. It is sufficient that some items are properly determined, and the configuration of the present embodiment is merely one example. 
     As can be understood from the above, in the display unit  13  of the present embodiment, the item that can be set by using the manual setting area  1341  changes depending on the type of operator who uses the screen thereby to execute the operation. 
     In the present embodiment, the number of manual setting areas  1341  displayed on the device management screen varies depending on the type of operator (user). In the present embodiment, it is so configured that, for each item, the manual setting area  1341  is displayed for the authorized user, and the manual setting area is not displayed for the unauthorized user. However, the above is merely an exemplification. It may be so configured that the manual setting area  1341  is displayed even for the unauthorized user, and the user&#39;s operation on the manual setting area  1341  is disabled. In this case, it may be so configured that the manual setting area  1341  is grayed out so as to make the user aware that the operation is disabled, for example. 
     (3-4. State Monitoring Screen) 
     The display unit  13  displays a state monitoring screen showing the operation state of the device possessed by the management system  100 .  FIG.  13    is a schematic diagram showing the state of displaying a state monitoring screen  135  on the screen  130  of the display unit  13 . By touch or the like, operating the state monitoring button  402  displayed in the menu area  400  can select the state monitoring screen  135 . As shown in  FIG.  13   , the state monitoring screen  135  includes a control state display area  500  that shows the control state of the management system  100 . Similar to the home screen  132  described above, the control state display area  500  is included in the header area  200 . 
     As shown in  FIG.  13   , the state monitoring screen  135  includes the sub-menu area  410 . The sub-menu area  410  is a band-shaped area provided beneath the header area  200 . The state monitoring screen  135  displays a content that accords to a button selected from among multiple buttons  411   g,    411   h,  and  411   i  displayed in the sub-menu area  410 . In the present embodiment, the buttons displayed in the sub-menu area  410  of the state monitoring screen  135  include a heat device button  411   g,  an electric device button  411   h,  and air conditioning device button  411   i.    
       FIG.  13    shows the screen seen when the electric device button  411   h  is selected. As shown in  FIG.  13   , when the electric device button  411   h  is selected, the state monitoring screen  135  displays an operation state of the electric device. The example shown in  FIG.  13    shows the operation states of the photovoltaic (PV) generating unit, the cogeneration system (CP), the power system, and the power load. 
     Although not shown in the drawings; when the heat device button  411   g  is selected, the state monitoring screen  135  displays the operation state of the heat device. The state monitoring screen  135  with the heat device button  411   g  selected shows the operation states of, for example, the boiler, the chiller, the cogeneration system, and the heat load. When the air conditioning device button  411   i  is selected, the state monitoring screen  135  displays the operation state of the air conditioning device. The state monitoring screen  135  with the air conditioning device button  411   i  selected shows the operation state of, for example, a gas heat pump. 
     As can be seen from the above, the state monitoring screen  135  includes plural screens that can be switched according to the type of device. That is, the state monitoring screen  135  is so provided as to be switchable according to the type of device. Types of devices include, for example, the heat device, the electric device, and the air conditioning device. In other words, the state monitoring screen  135  includes plural screens that can be switched according to the type of energy. The screen showing the operation state is so provided as to be switchable according to the type of device (or energy), thereby making it possible to easily view, as a moderate amount, the information on the operation state shown on the screen. 
     In the present embodiment, when any screen (for example, the home screen  132 ) other than the state monitoring screen  135  is displayed, selecting the state monitoring button  402  automatically selects a special button that is any of the multiple buttons  411   g  to  411   i  displayed in the sub-menu area  410 , thus displaying the screen that corresponds to the selected button. Which button is to be designated as the special button may be properly determined. For example, when the heat device button  411   g  is designated as the special button, selecting the state monitoring button  402  automatically selects the heat device button  411   g,  thus displaying the screen indicating the operation state of the heat device. 
     As shown in  FIG.  13   , the state monitoring screen  135  shows the operation state of the device below the sub-menu area  410 . The state monitoring screen  135  includes a device icon  1351  showing the device possessed by the management system  100 . The device icon  1351  is changed according to the type of device. In the example shown in  FIG.  13   , the photovoltaic (PV) generating unit, the cogeneration system (CP), the power system, and the power load are shown by device icons  1351  different from each other. By using these device icons  1351  thereby to show the operation state of each device, the user having viewed the screen can easily grasp the operation state of the device. Being changed according to the type of device may mean that the display unit  13  recognizes the type of device, thus automatically selecting the device icon  1351  according to the recognized type. Also, being changed according to the type of device may mean that the operator of the display unit  13  manually selects the device icon  1351  according to the type of device. 
     Further, the state monitoring screen  135  includes a numerical information area  1352  that shows the operation state of the device in a numerical value. The numerical information area  1352  is provided for each device. It is preferable that the numerical information area  1352  provided for each device is placed around the circumference of the device icon  1351  provided for each device. In the example shown in  FIG.  13   , each of the numerical information areas  1352  is placed below one of the device icons  1351 . Displaying the numerical information area  1352  on the state monitoring screen  135  makes it easy to accurately grasp the operation state of the device. Further, the numerical information area  1352  may be prevented from being displayed. 
     Further, the state monitoring screen  135  includes a letter information area  1353  that shows information about the device in letter. The letter information area  1353  is provided for each device. It is preferable that the letter information area  1353  provided for each device is placed around the device icon  1351  provided for each device. In the example shown in  FIG.  13   , each of the letter information areas  1353  is placed above one of the device icons  1351 . Displaying the letter information area  1353  on the state monitoring screen  135  can make it easy to grasp the type of device. The letter information area  1353  may be prevented from being displayed. 
     Further, the state monitoring screen  135  includes a connecting line  1354  connecting between the multiple device icons  1351 . Displaying the connecting line  1354  on the state monitoring screen  135  can make it easy to grasp the relation between the multiple devices. It is preferable that the connecting line  1354  is an arrow line. This makes it easy to grasp the flow of the energy. For example, in the example shown in  FIG.  13   , the direction of the arrow makes it possible to immediately grasp, in view of the state monitoring screen  135 , that the energy (power) is flowing from the photovoltaic (PV) generating unit, the cogeneration system (CP), and the system to the power load. The connecting line  1354  may be prevented from being displayed. 
     It is preferable that the connecting line  1354  is changed in display mode according to the type or mode of the energy. Types of energy include, for example, electric energy, heat energy, cold heat, and hot heat. Modes of energy include, for example, giving heat and taking heat. Another mode of energy includes, for example, the supply and demand of electric power. 
     The change in the display mode may be, for example, a change in the color of or a change in the line type of the connecting line  1354 . For example, the connecting line  1354  which shows the cold heat, and the connecting line  1354  which shows the hot heat may differ from each other in display mode. The connecting line  1354  showing the cold heat may be displayed by a blue line, and the connecting line  1354  showing the hot heat may be displayed by a red line. In addition, the connecting line  1354  which shows the flow of energy giving heat, and the connecting line  1354  which shows the flow of the energy that takes heat may be different in display mode. The connecting line  1354  showing the flow of energy giving heat may be shown as a solid line, and the connecting line  1354  showing the flow of the energy that takes heat may be shown by a broken line. 
     Further, the state monitoring screen  135  includes an energy state display icon  1355  that shows the energy state associated with the operation of the device. In the example shown in  FIG.  13   , the energy state display icon  1355  is displayed on the right side of the state monitoring screen  135 , but the display location thereof may be changed as needed. The energy state display icon  1355  may be prevented from being displayed. 
     Multiple types of energy state display icons  1355  are prepared, and are automatically switched according to the energy state. Displaying, on the state monitoring screen  135 , the energy state display icon  1355  with its displaying switched according to the energy state allows the user to easily grasp the energy state of the management system  100 . 
     The energy state is, in detail, the energy state of the management system  100 . The energy state may be determined based on, for example, an operation plan value. For example, when the management system  100  is operating with the energy close to the operation plan value, the energy state may be determined to be “good”. When the management system  100  is operating with the energy deviating from the operation plan value, the energy state may be determined to be “poor”. In the above configuration where a two-step determination is made, there may be two types of energy state display icons  1355 . 
     In the example shown in  FIG.  13   , the energy is subdivided into plural types of energy. Then, for each of the subdivided energy, the energy state is shown by using the energy state display icon  1355 . For the power load and the received power, the energy state display icon  1355  showing that the energy state is good is displayed. For the generated power, the energy state display icon  1355  showing that the energy state is poor is displayed. 
     The energy state may be shown by more than two steps, in which case the energy state display icon  1355  will have more than two types. Further, for being the screen showing the operation state of the electric device, the screen shown in  FIG.  13    displays the state of the energy related to the electricity. For example, when the screen shows the operation state of the heat device, the state of the heat-related energy may be displayed. For example, the energy state, such as a thermal load, a thermal output, a cold load, and a cold output, may be displayed by the energy state display icon  1355 . 
     The device icon  1351  displayed on the state monitoring screen  135  may be automatically switched according to the operation state of the device. In this case, multiple types of device icons  1351  may be prepared for each device.  FIG.  14    is an example of a case where multiple types of device icons  1351  are prepared for each device. 
     In  FIG.  14   , the device icon  1351  is an example of a device icon of the cogeneration system (CP). The device icon  1351  shown at the upper step in  FIG.  14    is a basic form of the device icon showing the cogeneration system. This basic form of the device icon  1351  is displayed in situations other than the three cases described below. 
     A device icon  1351   a shown on the left side of the lower step in  FIG.  14    is a device icon showing that the cogeneration system is in the operation state. The device icon  1351   a  is displayed when the cogeneration system is the operation state. A device icon  1351   b  shown in the lower middle in  FIG.  14    is a device icon showing that the cogeneration system is under maintenance. The device icon  1351   b  is displayed when the cogeneration system is under maintenance. A device icon  1351   c  shown on the right side of the lower step in  FIG.  14    is a device icon that shows that a warning (alarm) is issued to the cogeneration system. The device icon  1351   c  is displayed when the warning is issued to the cogeneration system. 
     The above shows the case where the device is the cogeneration system, but multiple types of device icons may be prepared for the other device as well. 
     Further, at least one of the display position and size of the device icon  1351  may be provided in a changeable manner. Similarly, at least one of the display position and size of the numerical information area  1352  may be provided in a changeable manner. Further, at least one of the display position and size of the letter information area  1353  may be provided in a changeable manner. Further, according to the change in the display position of the device icon  1351 , etc., the display position, etc. of the connecting line  1354  may be provided in a changeable manner. For example, the thickness of the connecting line  1354  may be provided in a changeable manner. Acquiring these configurations makes it possible to make the screen display that accords to the user&#39;s preference. 
       FIG.  15    is a diagram exemplifying the state of having changed the screen setting of the state monitoring screen  135  shown in  FIG.  13   . In the example shown in  FIG.  15   , the display position of each device icon  1351  is changed compared to that in  FIG.  13   . In addition, along with the change in the display position of each device icon  1351 , the display positions of each numerical information area  1352  and each letter information area  1353  are also changed compared to the case in  FIG.  13   . 
     In the example shown in  FIG.  15   , along with the change in the position of the device icon  1351 , etc., the display position and mode of the connecting line  1354  are also changed compared to the case in  FIG.  13   . In the example shown in  FIG.  15   , each device icon  1351 , each numerical information area  1352 , and each letter information area  1353  are larger in size of the display than in the case in  FIG.  13   . In the example shown in  FIG.  15   , the energy state display icon  1355  is in a state of not being displayed. 
     Changing the position and size of the display may be done, for example, by using the screen setting screen that is displayed by selecting the screen setting button (not shown) which is so provided as to be displayable in the menu area  400 . In the screen setting screen, the device icon  1351  which the user wants to display on the state monitoring screen  135  may be optionally selectable. Then, the various device icons  1351  selected may be set at optional positions within a displayable range on the state monitoring screen  135 . For the same type of device icon  1351 , multiple device icons  1351  of different sizes are prepared; the size of the device icon  1351  may be changed depending on which of the multiple device icons  1351  of different sizes is selected. However, it may be so configured that the size of the device icon  1351  is optionally changeable. 
     Further, in the screen setting screen, the type selection, display position, and size of the numerical information area  1352 , the letter information area  1353 , and energy state display icon  1355  may be freely set, similar to the device icon  1351 . Further, in the screen setting screen may be so provided as to allow for positioning, etc. of the connecting line  1354 . 
     (3-5. Modified Example) 
       FIG.  16    is a schematic diagram showing a state monitoring screen  135 X of a modified example. The state monitoring screen  135 X of the modified example is substantially the same as the state monitoring screen  135  shown in  FIG.  13    described above. The state monitoring screen  135 X includes a control button  1356  that allows for changing the control state of the device possessed by the management system  100 . This point differs from the above embodiment. 
     In detail, the control button  1356  is a virtual button that is displayed on the state monitoring screen  135 X. The control button  1356  is a soft button that switches the control of the device between run and stop (ON and OFF). Operating the control buttons  1356  displayed on the state monitoring screen  135 X by touch or the like makes the switching between run and stop of control of the device. Displaying the control button  1356  on the state monitoring screen  135 X makes it possible to manually set, on the state monitoring screen  135 X, the run and stop of control of the device. 
     Further, the control buttons  1356  may be provided for all devices that are displayed on the state monitoring screen  135 X and that can be controlled by the management system  100 , or may be provided only for some of the devices. In the example shown in  FIG.  16   , the control buttons  1356  are provided for the photovoltaic generating unit (PV) and cogeneration system (CP). For example, the control button  1356  may be provided for only one of the photovoltaic generating unit (PV) and the cogeneration system (CP). 
     The control button  1356 , like the device icon  1351 , etc., may be so provided as to be changeable in display position and size. In the example shown in  FIG.  16   , each of the control buttons  1356  associated one of the devices is placed around the device icon  1351  showing the associated device. In detail, each of the control buttons  1356  is placed to the right of one of the device icons  1351 . 
       FIGS.  17 A,  17 B, and  17 C  are diagrams for explaining about the operation of the control button  1356 .  FIG.  17 A  shows a screen example that is seen, in the state monitoring screen  135 X shown in  FIG.  16   , when the control button  1356  to the right of the device icon  1351  showing the cogeneration system is operated by touch or the like. As shown in  FIG.  17 A , operating the control button  1356  causes a pop-up display  1357  to appear on the state monitoring screen  135 X. 
     The pop-up display  1357  includes a switching operation area  1357   a  and an OK button  1357   b.  Sliding a slide portion  1357   c,  which is displayed by a black circle in the switching operation area  1357   a,  can make the switching between control stop (OFF) and control run (ON). In the present example, the cogeneration system was in a control stop state when the control button  1356  was operated, thus positioning the slide portion  1357   c  on the control stop side (left side). 
       FIG.  17 B  is a diagram showing the state of having operated the slide portion  1357   c  of the pop-up display  1357  shown in  FIG.  17 A . In detail,  FIG.  17 B  is a diagram showing the state of having operated the slide portion  1357   c  from the state shown in  FIG.  17 A  to the control run side (right side). In this state, operating the OK button  1357   b  fixes the selection of “Control Run”. That is, the control state of the device is changed from the control stop (OFF) state to the control run (ON) state. 
       FIG.  17 C  is a diagram showing that, in  FIG.  17 B , the OK button  1357   b  has been operated (e.g., touched). As shown in  FIG.  17 C , changing from the control stop state to the control run state also changes display of the control button  1356 . That is, the control button  1356  changes its display mode according to the control state of the device. This allows the user to confirm, on the state monitoring screen  135 X, that the control state of the device has been changed. 
     As shown in  FIG.  17 A , etc., the control buttons  1356  displayed on the state monitoring screen  135 X have a letter portion  1356   a,  a background area  1356   b,  and a frame area  1356   c.  The letter portion  1356   a  is a portion including a letter. In the present example, the letter portion  1356   a  includes letters “Control Stop” or “Control Run”. 
     The background area  1356   b  is an area that is overlapped with the letter portion  1356   a,  thereby to be included in a background of the letter portion  1356   a.  In the present example, the background area  1356   b  has an area larger than an area in which the letter included in the letter portion  1356   a  is displayed. The background area  1356   b  is rectangular in shape, extending in the right/left direction. The frame area  1356   c  is a frame area that surrounds an external edge of the background area  1356   b.    
     Changing the control state of the device properly changes the display modes of the letter portion  1356   a,  the background area  1356   b,  and the frame area  1356   c.    
       FIG.  18    is a diagram for explaining about the change in display mode of the control button  1356 . In  FIG.  18   , “Value of Device” shows a control signal which the control unit  11  (see  FIG.  2   ) possessed by the management system  100  automatically determines according to an operation setting. The control signal “ 0 ” means that the control is stopped (OFF, disabled), and the control signal “ 1 ” means that the control is running (ON, enabled). In  FIG.  18   , “Not Run of Manual Control State ” shows a state in which the manual setting is not running. The “OFF Control of Manual Control State” shows a state in which the control stop is manually set. The “ON Control of Manual Control State” shows a state in which the control run is manually set. In the present example, the manually set control command has priority over the control command determined by the control unit  11 . 
     As shown in  FIG.  18   , the display mode of the letter portion  1356   a  differs between the state in which the control of the device is stopped and the state in which the control of the device is running. In detail, the letters themselves are different, and the letter colors are different. The color of the letter is, as an example, black for control stop and white for control run. In addition, a state where being different is the letters themselves only while the letter color is the same is allowed. 
     Further, the display mode of the background area  1356   b  differs between the state in which the control of the device is stopped and the state in which the control of the device is running. In detail, the colors of the background area  1356   b  are different. In the present example, the background area  1356   b  is, as an example, white for control stop and black for control run. In addition, the difference in display mode of the background area  1356   b  may be, for example, hatched or not, rather than the difference in color. 
     In the present example, the control button  1356  is displayed in a different mode according to the reason why the device is in the current control state. In detail, the display mode of the frame area  1356   c  changes according to whether the reason for the current control state of the device is due to the automatic control by the control unit  11  or due to the manual control. In the case of the automatic control, the frame area  1356   c  is not hatched. The frame area  1356   c  is white. Meanwhile, when in the case of the manual control, the frame area  1356   c  is hatched. The difference in display mode of the frame area  1356   c  may not be hatched or not, but may be, for example, the difference in type of hatching or the difference in color. 
     In the example shown in  FIG.  16   , the control of the device is automatically stopped for the cogeneration system. Due to this, the letter in letter portion  1356   a  is “Control Stop” in black. The background area  1356   b  is white. The frame area  1356   c  is not hatched (white). 
     By using the control button  1356 , making the cogeneration system from in the state shown in  FIG.  16    to the control run means that the cogeneration system has been manually changed to the control run. Due to this, as shown in  FIG.  17 C , the letter in the letter portion  1356   a  is “Control Run” in white. The background area  1356   b  is black. The frame area  1356   c  is hatched. 
     In the present example, the display unit  13  displays the device management screen  134  (see  FIG.  19 A , etc.) whose display content is changed in conjunction with the operation of the control button  1356 . The device management screen  134  is a screen that shows a detailed state for each device. Displaying the device management screen  134  that is in conjunction with the state monitoring screen  135 X can grasp the state of the device from various viewpoints, which is convenient. Further, the device management screen  134  is displayed by operating, such as touching, the device management button  404 , as described above. 
       FIGS.  19 A and  19 B  are each a diagram for explaining that the device management screen  134  is in conjunction with the operation of the control button  1356 .  FIG.  19 A  exemplifies a part of the screen displayed when selecting the device management button  404  from the state of displaying the state monitoring screen  135 X shown in  FIG.  16   .  FIG.  19 B  exemplifies a part of the screen displayed when selecting the device management button  404  from the state of displaying the state monitoring screen  135 X shown in  FIG.  17 C . 
     Note that, in the device management screens  134  shown in each of  FIGS.  19 A and  19 B , the “Management Address” is the address defined in the control unit  11  (see  FIG.  2   ). “Type” shows input or output classification. “Item Name” is a specific name of the object whose input or output is managed. The “Current State” shows the current state of the input or output of each item managed by using the management address. The “Control Reason” shows the control-related reason for the current state of the input or output of each item managed by using the management address. The “Manual Setting” displays information related to the manual setting of the input information or output information of each item managed by using the management address. Further, the “Cogeneration” in each of  FIGS.  19 A and  19 B  denotes cogeneration system. 
     As described above, in the example shown in  FIG.  16   , the cogeneration system is automatically controlled to stop by the control signal by the control unit  11 . Corresponding to the above, in the device management screen  134  shown in  FIG.  19 A , the external operation command of the cogeneration system is “disabled” (control stop). 
     Assume that, in the state shown in  FIG.  16   , the control button  1356  caused to correspond to the cogeneration system is manually operated, thereby to start the running of the control of the cogeneration system, as shown in  FIG.  17 C . In this case, as shown in  FIG.  19 B , on the device management screen  134 , the external operation command of the cogeneration system is “enabled” (Control Run). Further, the control reason for the external operation command of the cogeneration system is “Manual”, and an operation button  1341  for switching the manual setting is displayed with the letters “Under Manual Operation”. That is, the display content of the device management screen  134  is changed in conjunction with the operation of the control button  1356 . 
     The above has shown that the display content of the device management screen  134  is changed in conjunction with the operation of the control button  1356  displayed on the state monitoring screen  135 X. Similarly to the above, the display mode of the control button  1356  is changed in conjunction with the operation of operation button  1341  that switches the manual setting on the device management screen  134 . 
     Also, in the present example; when the manual control is not running, the operation button  1341  that switches the manual setting on the device management screen  134  is not hatched. Meanwhile, when the manual control is running, the operation button  1341  that switches the manual setting on the device management screen  134  is hatched. This is similar to the method of changing the display mode of the frame area  1356   c  (hatched or not depending on whether or not by the manual control) of the control button  1356 . That is, in the present example, the method of changing the display mode of the control button  1356  and the method of changing the display mode of the operation button for the manual setting on the device management screen  134  have commonality. Bringing about this uniformity makes it easy to grasp the screen display. 
     &lt;4. Notes, Etc.&gt; 
     The various technical features disclosed in the present specification can be modified in various ways without departing from the gist of the technical creation thereof. Further, the multiple embodiments and modified examples shown in the present specification may be combined to the extent possible. 
     &lt;5. Appendices&gt; 
     An exemplary display unit in the present specification is a display unit of a management system that manages energy, wherein the display unit may have a configuration where the management system displays a state monitoring screen that shows an operation state of a device of the management system, and the state monitoring screen includes a device icon that shows the device (first configuration). 
     In the display unit having the first configuration, the device icon may have a configuration to be changed according to a type of the device (second configuration). 
     In the display unit having the first or second configuration, the state monitoring screen may have a configuration to include a numerical information area that shows the operation state in numerical value (third configuration). 
     In the display unit having any of the first to third configurations, the state monitoring screen may have a configuration to include a letter information area that shows information on the device in letter (fourth configuration). 
     In display unit having any of the first to fourth configurations, the state monitoring screen may have a configuration to include a connecting line that connects between the plural device icons (fifth configuration). 
     In the display unit having the fifth configuration, the connecting line may have a configuration to be changed in display mode according to a type or mode of the energy (sixth configuration). 
     In the display unit having any of the first to sixth configurations, the state monitoring screen may have a configuration to include an energy state display icon that shows an energy state associated with an operation of the device (seventh configuration). 
     In the display unit having any of the first to seventh configurations, at least one of a display position and size of the device icon may have a configuration to be so provided as to be changeable (eighth configuration). 
     In the display unit having any of the first to eighth configurations, the state monitoring screen may have a configuration to include a plurality of screens switchable according to a type of the device (ninth configuration). 
     In the display unit having any of the first to ninth configurations, the state monitoring screen may have a configuration to include a control state display area that shows a control state of the management system (tenth configuration). 
     In the display unit having any of the first to tenth configurations, the state monitoring screen may have a configuration to include a control button that causes a control state of the device to be changeable (eleventh configuration). 
     In the display unit having the eleventh configuration, the control button may have a configuration to be changed in display mode according to the control state of the device (twelfth configuration). 
     In the display unit having the eleventh or twelfth configuration, the display unit may have a configuration to display a device management screen having display content that changes in conjunction with an operation of the control button (thirteenth configuration). 
     REFERENCE SIGNS LIST 
       2 : renewable energy generating unit (device) 
       3 : storage battery (device) 
       4 : boiler (device) 
       5 : heat pump (device) 
       6 : hot water tank (device) 
       7 : cogeneration system 
       13 : display unit 
       100 : management system 
       130 : screen 
       134 ,  134 A: device management screen 
       1341 : manual setting area 
       1342 : current state display area 
       1343 : control reason display area 
       1346 : manual tab (operation area) 
       135 ,  135 X: state monitoring screen 
       500 : control state display area 
       1351 : device icon 
       1352 : numerical information area 
       1353 : letter information area 
       1354 : connecting line 
       1355 : energy state display icon 
       1356 : control button