Mocomtech CDM-QX - Manual (Page 70)

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision 7
Front Panel Operation MN/CDMQX.IOM
5–4
5.1.4 Front Panel Vacuum Fluorescent Display (VFD)
The CDM-Qx/QxL features a Vacuum
Fluorescent Display (VFD). The VFD is an
active display showing two lines of 40
characters each. It produces a blue light, the brightness of which can be controlled by the user.
Compared to a Liquid Crystal Display (LCD), it has greatly superior viewing characteristics and
does not suffer problems of viewing angle or contrast.
On most menu screens, the user will observe a flashing solid block cursor, which blinks at a once-
per-second rate. This indicates the currently selected item, digit, or field. Where this solid block
cursor would obscure the item being edited (for example, a numeric field) the cursor
automatically changes to an underline cursor.
If the user were to display the same screen for weeks at a time, the display could become ‘burnt’
with this image. To prevent this, the unit has a ‘screen saver’ feature that activates after 1 hour.
The top line of the display will show the Circuit ID (which can be entered by the user) and the
bottom line will show the circuit Eb/No value (if there is a demod and it is locked) followed by
‘Press any key....’. The message moves from right to left across the screen, then wraps around. If
there are multiple circuits, their messages and Eb/No’s will be displayed sequentially. Press any
key to return to the previous screen.
The display is divided into two areas – left-hand and right-hand. The left-hand display area (also
referred to as the slot screen) can be accessed by using the ◄ arrow key if the menu-level is
MAIN, CONFIG, MONITOR, or INFO (and there is more than one installed module present
for selection).
To go back to the right-hand display area (also referred to as the menu screen), just press
CLEAR
or ENTER
. Note that, by pressing
ENTER
selects that plug-in card for menu screen operations.
The functionality of the two display areas is outlined in the sections that follow.
5.1.4.1 VFD – Left-hand Display Area
The left-hand display area (or slot screen) efficiently indicates what is installed into each of the
chassis’ four plug-in slots, and which slot is currently being addressed. The following example
displays four ungrouped plug-ins:
TX TX | (right-hand display area)
<RX> RX | (right-hand display area)
This display indicates modulators in the top slots, and demodulators in the bottom slots. The
orientation of these four indicators serve as a mnemonic for the orientation of the four slots as
viewed from the rear of the chassis – e.g., the left-hand TX displayed on the VFD corresponds
with the top left slot when looking at the chassis rear panel. An empty slot is left blank.
In the above example, the left RX is highlighted, indicating that this is the selected slot. All
monitor functions (including the front panel LEDs) reflect the status of this slot. All parameters
selected from the menu tree while this slot is selected apply either to this slot or to common
functions. The menus for common functions appear redundantly in all four slots. To change slots,
move the cursor to the desired slot, and press
ENTER
.