Patent attributes
When first screen customizing information is changed in order to change a first display screen, a local controller sends first setting information indicating a changed part of the first screen customizing information to a server. When second screen customizing information is changed in order to change a second display screen, a remote controller sends second setting information indicating a changed part of the second screen customizing information to the server. The server sends first renewal information identical to the second setting information to the local controller and sends second renewal information identical to the first setting information to the remote controller; the local controller changes the first display screen in accordance with the first renewal information; and the remote controller changes the second display screen in accordance with the second renewal information.