JMaCS Implementation 11.3-beta

Last updated: 2008-05-05

This is an implementation of the monitoring and control system described at jmacs.org.

How to launch a JMaCS user-interface

1. Check special requirements.
2. Install Java--Standard Edition, version 5 or 6 (current).
3. Set console preference.
4. Launch app:
   • stand-alone application (using Java Web Start);
   • applet (embedded in browser window).
5. Agree to run it as a trusted app (when prompted). This is necessary because it has to be able to do things (such as create new Java class loaders) which are not permitted inside the Java sandbox.

How to connect to the demo target

1. Enter username.
2. Press return or click 'connect...' button.
3. Supply password.

Note that you may only connect to a given target sequentially (using the same username). Also, if your session should end abruptly (i.e. without disconnecting or exiting), you are currently subject to a timeout period of a few minutes, after which you'll be disconnected automatically (so that you can reconnect).

How to open a monitor-window or control-panel

'Occupied' nodes of the device-navigator are indicated by a two-character prefix, indicating the disposition of any monitor-window and control-panel it provides, respectively: '-' indicates closed, '+' indicates open, and '.' indicates absent.

1. Navigate to the device of interest (e.g. 'eyes.left'), using the arrow-keys or mouse. Make sure it's selected and has the focus.

   

2. Hit the SPACEBAR to open/close the monitor window, or SHIFT-SPACEBAR to open/close the control panel. Note the change from '-' to '+'.

   . . .

Notes

• Only the control panel of the selected device (if currently open) is displayed, always next to the navigator. The monitor window of the selected device is highlighted.
• Commands submitted from the commandline--type, then hit return--will target the selected device.
• The title of any monitor window which didn't get refreshed turns red.
• Only the clocks of device-interface client hosts are required to be in sync with the server host one. The time displayed here is the approximate time on the server, the indicated number of seconds (synchronisation delay, e.g. '+2.0') in the past.
• If anything starts to flash and beep, just click on it to acknowledge the alert (or select the 'File > Muted' menu item).

Tips

• Control panels usually generate textual commands, which can be recalled subsequently on the commandline (using the arrow keys).
• Use the TAB key to change the focus between the device navigator, control-panel widgets, and the commandline.
• By assuming the role of 'principal user' (see 'server' control panel), you can arrange for all other controlling users to be prompted for confirmation whenever they submit a command.
• Type the first letter of the device name to jump directly to it, when the device navigator has the focus.
• In the unlikely event :-) that the applet should become unresponsive, close the window, type 'x' into the console window (to clear the class-loader cache), and revisit the applet page.

• The app requests a connection to a non-HTTP server (which your firewall might block).
• To run the applet on Java 5 (JDK 1.5), you have to first disable applet caching (in order to work around a known bug):
  1. Launch the Java Preferences utility.
  2. In the General tabbed pane, click on Settings... > View Applets... and uncheck the Enable Caching checkbox.
  3. Click OK. (On Mac OS X, click on File > Exit.)
  4. Restart the browser.

This will cause each Java app launched to be accompanied by a console. This displays any messages written by the app, and provides some useful controls.

1. Launch the Java Preferences utility.
2. Select the Advanced tab.
3. Select Java console.
4. Select Show console.