CG-1280 Rev. N 09/13 - General Dynamics SATCOM Technologies

OverviewSystem fault status is reported in inverse, double-size characters in the field belowthe Tracking mode status line. In the event of multiple fault conditions, the faultmessages are scrolled continuously at approximately one-second intervals. An audiblealarm (if the alarm option is turned on) accompanies any major fault and may besilenced from the front panel keypad (refer to Section 5.8.6.14 for information onuser interface options). To the right of “UTC”, an asterisk “*” will appear if anoptional time and frequency processor board (IRIG-B) is installed and has locked ontoan external signal at least once (refer to Section 2.4.1.8).The lower portion of the display allows fully menu-driven selection of control modes,parameter editing, etc. A logical tree structure provides for easy and efficient systemoperation with minimal reliance upon system operation manuals. One item in eachmenu is always highlighted by an inverse-video cursor, which is controlled by keypaddirection keys. The [ENTER] key then selects the highlighted item either for activationor editing. A dedicated [HELP] key and context-sensitive help messages serve toremind the operator of operational functions.The display control PCB receives commands from the CPU through a serial link andprovides appropriate decoding and driver functions for illumination of the display.2.5.1.3 The KeypadCommands from the keypad are decoded and serialized through a dedicated keypadcontrol PCB and sent to the CPU through a serial link shared with the display controlserial link. A speaker located on the keypad control circuit board provides an audiblealarm for fault conditions. Refer to Table 2-9 for explanations of the function of eachkey.2-23