Comtech EF Data CDM-550T - Manual (Page 30)

CDM-550T Satellite Modem Revision 3
Physical Description MN/CDM550T.IOM
4.2 Front Panel
On the front panel of the unit is the Vacuum Fluorescent Display (VFD), keypad, and eight Light
Emitting Diode (LED) indicators. The user enters data via the keypad, and messages are
displayed on the VFD. The LEDs indicate, in a summary fashion, the status of the unit.
The VFD is an active display showing two lines, each of 24 characters. It produces a blue light,
the brightness of which can be controlled by the user. It has greatly superior viewing
characteristics compared to a Liquid Crystal Display (LCD), and does not suffer problems of
viewing angle or contrast.
The keypad comprises six individual keyswitches, mounted directly behind a fully sealed
membrane overlay. They have a positive ‘click’ action, which provides the user with tactile
feedback. These six switches are identified as [
↑] [↓] [←] [→], ENT (Enter) and CLR (Clear).
The functions of these keys are described in Chapter 6. FRONT PANEL OPERATION.
There are eight LED indicators. The functions of these indicators are shown in Table 4-1:
Table 4-1. Front Panel LED Indicators
LED Color Condition
Unit
Status
Red A Unit Fault exists (Example: PSU fault)
Orange No Unit Faults, but a Traffic Fault exists
Green No Unit Faults, or Traffic Faults
Transmit
Traffic Green No Tx Traffic Faults
Off A Tx Traffic fault exists OR the Tx Carrier is in OFF state
Receive
Traffic Green No Rx Traffic Faults (demod and Viterbi decoder are locked, everything is OK)
Off An Rx Traffic fault exists (the demod may still be OK)
On line
Green The Unit is On Line, and carrying traffic
Off
The Unit is Off Line (standby) - forced by externally connected 1:1 or 1:N
redundancy system
Stored
Event Orange
There is a Stored Event in the log, which can be viewed from the front panel, or
retrieved via the remote control interface
Off There are no Stored Events
Remote
Orange The Unit is in Remote Mode - local monitoring is possible, but no local control
Off The Unit is in Local Mode - remote monitoring is possible, but no remote control
EDMAC
Mode Orange Framing on, EDMAC on, and unit defined as Slave
Off Either no EDMAC, EDMAC Master, or Transparent mode is selected
Test Mode
Orange A Test Mode is selected (Example: IF Loopback)
Off There is no Test Mode currently selected
IMPORTANT
In general, the Alarm relay state will reflect the state of the Front Panel LEDs.
For instance, if the Unit Status LED is RED, the Unit Alarm relay will be active,
etc. The one exception is the Transmit Traffic relay. This will only be activated if
a Transmit Traffic Fault exists – it does not reflect the state of the TX carrier.
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