Title of Invention: SURVEILLANCE SCREEN DISPLAY DEVICE Technical Field [0001] The present invention relates to a monitoring screen display device in a monitoring system for acquiring data from sensors and track circuits installed in a plant, a train route, and the like which are monitoring targets, and for monitoring a state and a situation of the monitoring target. Background Art [0002] A monitoring screen such as a route map and a system diagram displayed on a monitoring screen display device is edited with a dedicated editor to be stored as screen data. In a conventional monitoring screen display device, one piece of monitoring screen data is created for one monitoring screen. [0003] Techniques for creating a plurality of pieces of monitoring screen data for one monitoring screen are disclosed in, for example, Patent Documents 1 and 2. In the technique disclosed in Patent Document 1, when a user inputs order of stations according to the route map on the monitoring screen display device, a plurality of pieces of monitoring screen data in an adjacent relationship are connected to create one route map file. [0004] In the technique disclosed in Patent Document 2, the adjacent relationship is specified by using mapping data between the monitoring screen data, and the user can intuitively grasp the adjacency relationship of each monitoring screen data by performing expansion, reduction, and tilting as necessary. Prior Art Documents Patent Documents [0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-220951 Patent Document 2: Japanese Patent Application Laid-Open No. 2010-215018 Summary of Invention Problems to be Solved by the Invention [0006] In the monitoring screen display devices disclosed in Patent Documents 1 and 2 described above, there is a problem that since the user is required to specify the adjacent relationship between the pieces of screen data upon creating the screen data or after creating the screen data, it takes time and effort for the user. [0007] An object of the present invention is to provide a monitoring screen display device capable of identifying pieces of screen data in an adjacent relationship without a user's operation of designating the adjacent relationship between the pieces of screen data, and connecting the pieces of screen data to be displayed. Means for Solving the Problems [0008] A monitoring screen display device of the present invention includes: a screen data storage unit configured to store screen data of a monitoring screen for monitoring a monitoring target; a monitoring screen display control unit configured to display the monitoring screen on a display device by using the screen data stored in the screen data storage unit; a monitoring target model storage unit configured to store monitoring target model information about a monitoring target model representing a logical structure of the monitoring target; a screen connecting unit configured to connect a plurality of pieces of the screen data stored in the screen data storage unit; a connected screen display control unit configured to display the connected monitoring screen on the display device by using the pieces of screen data connected by the screen connecting unit; and a component moving unit configured to move a position of a screen component in each of the monitoring screens. The screen data stored in the screen data storage unit includes attribute information on a screen component arranged on the monitoring screen. Each of the monitoring target model information and the attribute information includes signal identification information assigned to the monitoring target. The monitoring target model represents a logical structure of the monitoring target by using the signal identification information. The screen connecting unit finds pieces of screen data of monitoring screens in an adjacent relationship by using the signal identification information included in the monitoring target model information and the signal identification information included in the attribute information, and connects the found pieces of screen data according to the adjacent relationship. When positions of the screen components and widths of the screen components in an adjacent relationship are different on the connected monitoring screen, the component moving unit moves the screen component so that the positions of the screen components and the widths of the screen components in the adjacent relationship are identical. Effects of the Invention [0009] According to the monitoring screen display device of the present invention, the screen connecting unit finds the pieces of screen data of the monitoring screens in the adjacent relationship by using the signal identification information included in the monitoring target model information and the signal identification information included in the attribute information on the screen component, and connects the found pieces of screen data according to the adjacent relationship. Thus, the pieces of screen data in the adjacent relationship can be identified without a user's operation of designating the adjacent relationship between the pieces of screen data, and can be connected to be displayed. Therefore, the user can save time and effort on designating the adjacent relationship between the pieces of screen data, and a monitoring screen display device excellent in convenience can be achieved. [0010] In addition, if positions of the screen components and widths of the screen components in an adjacent relationship are different on the connected monitoring screen, the component moving unit moves the screen component so that positions of the screen components and widths of the screen components in the adjacent relationship are identical. Thus, since the positions of the screen components in the adjacent relationship can be aligned without the user's operation upon connection of the screens, the user can save time and effort on the alignment of the screen components. In addition, since the connection is made without changing the size and the line width of the screen components, the screen can be displayed as one screen without a sense of discomfort. [0011] The objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. Brief Description of Drawings [0012] Fig. 1 is a block diagram illustrating a configuration of a monitoring screen display device 10 according to a first embodiment of the present invention. Fig. 2 is a block diagram illustrating a hardware configuration of the monitoring screen display device 10 according to the first embodiment of the present invention. Fig. 3 is a diagram illustrating an example of route model information. Fig. 4 is a diagram illustrating another example of route model information. Fig. 5 is a diagram illustrating an example of component attribute information. Fig. 6 is a flowchart illustrating a processing procedure of screen display processing on the monitoring screen display device 10. Fig. 7 is a flowchart illustrating a processing procedure of connecting target screen data search processing in step ST5 in Fig. 6. Fig. 8 is a diagram illustrating an example of a route map. Fig. 9 is a diagram illustrating an example of a route map. Fig. 10 is a diagram illustrating an example of component attribute information. Fig. 11 is a diagram illustrating an example of route model information. Fig. 12 is a flowchart illustrating a processing procedure of screen connecting processing in step ST6 in Fig. 6. Fig. 13 is a diagram illustrating an example of a connected screen. Fig. 14 is a block diagram illustrating a configuration of a monitoring screen display device 10A according to a second embodiment of the present invention. Fig. 15 is a flowchart illustrating a processing procedure of connecting target screen data search processing in step ST5 according to the second embodiment of the present invention. Fig. 16 is a diagram illustrating an example of association. Fig. 17 is a flowchart illustrating a processing procedure of screen connecting processing in step ST6 according to the second embodiment of the present invention. Fig. 18 is a diagram illustrating an example of component attribute information. Fig. 19 is a diagram illustrating an example of a monitoring screen. Fig. 20 is a diagram illustrating an example of a monitoring screen. Fig. 21 is a diagram illustrating an example of a monitoring screen. Fig. 22 is a diagram illustrating an example of a monitoring screen. Fig. 23 is a block diagram illustrating a configuration of a monitoring screen display device 10B according to a third embodiment of the present invention. Fig. 24 is a flowchart illustrating a processing procedure of screen connecting processing in step ST6 according to the third embodiment of the present invention, Fig. 25 is a diagram illustrating an example of a connected screen. Fig. 26 is a block diagram illustrating a configuration of a monitoring screen display device IOC according to a fourth embodiment of the present invention. Fig. 27 is a diagram illustrating an example of association. Fig. 28 is a flowchart illustrating a processing procedure of screen connecting processing in step ST6 according to the fourth embodiment of the present invention. Fig. 29 is a diagram illustrating an example of a connected screen. Fig. 30 is a block diagram illustrating a configuration of a monitoring screen display device 10D according to a fifth embodiment of the present invention. Fig. 31 is a diagram illustrating an example of system model information. Fig. 32 is a diagram illustrating an example of component attribute information. Fig. 33 is a flowchart illustrating a processing procedure of connecting target screen data search processing in step ST5 according to the fifth embodiment of the present invention. Fig. 34 is a diagram illustrating an example of a system diagram. Fig. 35 is a diagram illustrating an example of a system diagram. Fig. 36 is a diagram illustrating an example of component attribute information. Fig. 37 is a diagram illustrating an example of system model information. Fig. 38 is a diagram illustrating an example of association. Fig. 39 is a flowchart illustrating a processing procedure of screen comiecting processing in step ST6 according to the fifth embodiment of the present invention. Fig. 40 is a diagram illustrating an example of screen components before connection. Fig. 41 is a diagram illustrating an example of a connected screen. Description of Embodiments [0013] (Dl + a)). [0115] In step ST94, if it is determined that D2 > (Dl + a) (a is an arbitrary value) is true, the route component extending unit 27 extends one of the route components in step ST95 so that the distance D2 between the route components in the adjacent relationship is the same as Dl. For example, it is assumed that the screen positioned on the left side upon connection is the screen data 101 illustrated in Fig. 8 and the screen positioned on the right side upon connection is the screen data 103 illustrated in Fig. 19. The screen data 101 and the screen data 103 are connected to obtain the screen data 201 illustrated in Fig. 13, and the distance in the x-axis direction between the route component 1011 and the route component 1021 is larger than the distance between other route components. In this case, the route component extending unit 27 extends the route component 1021 in a direction of approaching the route component 1011 in the x-axis direction. [0116] Fig. 25 is a diagram illustrating an example of a connected screen. Fig. 25 illustrates an example where the route component 1021 is extended. In the example illustrated in Fig. 25, the route component 1012 is extended, but the route component 1011 may be extended in a direction of approaching the route component 1021. In addition, the route component 1011 and the route component 1021 may be extended in a direction of approaching each other. [0117] As described above, in the present embodiment, since the space between the route components in the connecting portion can be made the same as the space between other route components upon connection of screens, a screen in which the connecting portion is hardly noticeable at a glance can be obtained. [0118]