Overview
System fault status is reported in inverse, double-size characters in the field below
the Tracking mode status line. In the event of multiple fault conditions, the fault
messages are scrolled continuously at approximately one-second intervals. An audible
alarm (if the alarm option is turned on) accompanies any major fault and may be
silenced from the front panel keypad (refer to Section 5.8.6.14 for information on
user interface options). To the right of “UTC”, an asterisk “*” will appear if an
optional time and frequency processor board (IRIG-B) is installed and has locked onto
an 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 system
operation with minimal reliance upon system operation manuals. One item in each
menu is always highlighted by an inverse-video cursor, which is controlled by keypad
direction keys. The [ENTER] key then selects the highlighted item either for activation
or editing. A dedicated [HELP] key and context-sensitive help messages serve to
remind the operator of operational functions.
The display control PCB receives commands from the CPU through a serial link and
provides appropriate decoding and driver functions for illumination of the display.
2.5.1.3 The Keypad
Commands from the keypad are decoded and serialized through a dedicated keypad
control PCB and sent to the CPU through a serial link shared with the display control
serial link. A speaker located on the keypad control circuit board provides an audible
alarm for fault conditions. Refer to Table 2-9 for explanations of the function of each
key.
2-23
To Next Page
Loading...
Need help?
General