The FXC System consists of two major components: the client component that allows the user to display and interact with meteorological data
and the servers that are responsible to provide various types of data to the client. In some special cases the client and servers reside on the same machine.
The FXC Server comprises a collection of servers: DepictableServer, ScribbleServer, ChatServer, BaselineServer, PointServer, DispatchServer, and FileMonitor.
The DepictableServer is responsible for interfacing with the AWIPS Software and exporting graphic products. It must therefore be hosted on a machine that
has direct access to the AWIPS Database and is able to run the AWIPS 5.0 (or later) software. The location of the ScribbleServer and other servers is more flexible
and it is anticipated that in the future, FXC may actually reassign these servers automatically if the hosts fail. During a collaborative session each server communicates
with the clients independently, i.e., it does not broadcast the data to all clients. As a result, some degradation in performance may occur when a large number of
clients are connected for a collaborative session.
Although the AWIPS Database is the primary and most extensive source of data, FXC can also obtain data (in image form) from Web servers and integrate
data from other sources. The local data integration capability is restricted at this time to display of surface data that has been stored in netCDF format.
Figure 1 illustrates the different data sources available to a user.
FXC Clients are usually located remotely. In order for a client to connect to a server, the user selects the desired server from the FXC Menu. Once the connection is
made to the server, the client has access to most of the AWIPS Database at the host office. Some menu item and table changes are necessary to add additional
AWIPS products to the FXC User Interface.
FXC is a Java 1.3 application that incorporates Remote Method Invocation (RMI) and is multi-threaded. FXC executes on PCs running Win98, WinNT, Win2000,
Windows XP, and Linux. Recommended machine attributes include 1 GHz cpu speed, 1 GB RAM, and 20 GB or larger disk. A network connection (DSL, ISDN,
or Ethernet) is also necessary. FXC is able to retrieve processed data from an AWIPS Database, web server, and local databases.
2.1 FXC Operating Modes
FXC has three basic operational modes: local, remote, and collaborative.
Local Mode - In local mode, the client is not connected to any AWIPS Server. However, the user does have access to selected
data from remote Web servers and possibly some local data. This mode is useful for preparing briefing displays that do not require
real-time data.
Remote Mode - In remote mode, the user is connected to an AWIPS Server that the user has selected from the FXC Menu. This
allows the user to access real-time meteorological data at the remote server. The user can display a variety of data and perform such
functions as zooming, panning, changing colors, overlaying graphics, and animation on the client. The FXC Server can accommodate a
number of concurrent and independent clients. The maximum number of clients is controlled from a menu on the server.
Collaborative Mode - In collaborative mode, the user can perform all of the same functions as in remote mode with the added
capability of simultaneously updating or controlling the screen of other users. An extensive drawing capability is available that allows the
user to annotate the screen and share the annotation with the other collaboration session participants. There is also a chat capability that
allows users to exchange text messages. Only one collaborative session can be held at a time. All users connected to a common server are
part of the same session. The session can remain active although all clients have disconnected from the server. This allows users to rejoin the
session at a later time.
2.2 Input Devices
There are two devices which enable the user to put information into the FXC Graphical Interface to invoke a desired action: a
mouse and a keyboard.
2.2.1 Keyboard Functions
The keyboard is used to enter text in the Discussion Graphic User Interface for "chat" functionality with collaboration participants. The keyboard is also
used to enter AFOS text product identifiers into the text interface. Additionally, the keyboard is used for annotating manually-generated graphics. Most
FXC display functions may be performed using the keyboard by holding the Alt Key and striking the "Hot Key" indicated by an underlined character in
every menu and submenu. Finally, certain menu commands may be invoked using "Accelerator Key" combinations listed to the right of the associated
menu items; for example, Ctrl+A will toggle looping just as if the user selected the Looping Menu item.
2.2.2 Mouse Functions
The mouse is used in a conventional manner for all other FXC actions. The mouse functions are designed for a three-button mouse.
In the event that FXC is running on a system with a two-button mouse, middle button functions may be accomplished by depressing
and holding the "Alt" Key and clicking with the left button. Two examples of middle-button functions are zooming a display or
toggling the Manual Graphics to editable mode.
Basic display functions of zoom, pan, and unzoom are performed using the mouse. Clicking the middle mouse button will cause the
display to incrementally zoom, centered on the position of the mouse cursor. One click of the left mouse button will incrementally
unzoom, with the resulting display centered on the position of the cursor when clicked. To pan a zoomed display, depress and hold
the middle mouse button, then drag the cursor in the desired direction to shift the display. The panned display will center on the
location of the mouse cursor when the middle button is released.
Displayed products may be toggled on and off by placing the mouse cursor over the desired product legend (in the lower right portion
of the display) and click once with the left mouse button. To change the color of a graphic overlay or background map, place the
mouse cursor on the desired product label and click once with the right mouse button to reveal a pop-up menu with color selections.
Additionally, any individual displayed product may be unloaded from the display by placing the mouse cursor over the selected product
label and clicking once with the right mouse button, revealing a pop-up menu, and selecting the "Unload" option.
Other mouse functions are toggling background maps and map legends on and off of the display, and unzooming to 1:1. These display
controls are available in a pop-up menu which is revealed by placing the mouse cursor anywhere in the main display window and
clicking once with the right mouse button. The resulting pop-up window offers:
Show Maps (toggle on or off);
Show Map Labels (toggle on or off);
Zoom 1:1.
Summary of mouse button functions:
Mouse Button 1 (left) - click to zoom out (unzoom). The resulting display will be centered on the cursor.
NOTE:
Unzoom is disabled with any editable graphic (Baselines, Points, Drawing Tools) in the display.
Toggle the editable graphic to uneditable to unzoom.
Mouse Button 1 (left) - click with cursor over a product legend to toggle that product on or off of the display.
Mouse Button 2 (middle) - with cursor in the display window, click to incrementally zoom. Zoomed display will be
centered on the cursor position.
Mouse Button 2 (middle) - with cursor over an editable product legend (Baselines, Points, Drawing Tools), click to
toggle between editable and not editable.
Mouse Button 2 (middle) - depress and hold button while dragging cursor to pan a zoomed display. Display will center
on cursor when button is released.
Mouse Button 3 (right) - click with cursor over a product legend to open a popup menu from which you can change overlay
color or unload that product from the display.
Mouse Button 3 (right) - click with cursor anywhere in the display to open a popup window that provides options to zoom
out to 1:1, or to toggle map backgrounds and map legends.
