GE D90 Plus Instruction Manual page 86

FRONT PANEL OVERVIEW
76
Figure 54: Typical annunciator display
There are three control buttons at the bottom of the display.
• The Next Page button navigates through the configured alarm, self-test and product
information pages. It should be noted that pages that contain no configured alarms
are not displayed.
• The Next Alarm button navigates horizontally though the current alarms that are
active, from left-to-right, starting with the first row of alarms. A border is drawn
around the current alarm.
• The Ack/Reset button is used to acknowledge alarms or reset latched and
acknowledgeable alarms that are in the ringback state.
The annunciator alarm sequence conforms to ISA 18.1-1979 (R1992) standard, type R.
Figure 55: Annunciator alarm sequence
The annunciator states are described in the following table.
Table 5: Acknowledgeable alarm states
Sequence (initial Process (status)
state)
Normal Normal
Normal Abnormal
Alarm Normal
Alarm Normal
Alarm Abnormal
Acknowledged Abnormal
Acknowledged Normal
Ringback Normal
Ringback Abnormal
The visual indications are displayed as follows.
• Off: grey text on a darker grey background.
• On: user-configurable.
• Fast flash: Alternating between the off state and the on state two times per second.
Pushbutton
(input)
N/A
N/A
N/A
Acknowledged
Acknowledged
N/A
N/A
Reset
N/A
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: INTERFACES
Sequence (final Visual indication
state)
N/A Off
Alarm Fast flash
Alarm Fast flash
Normal Off
Acknowledged On
Acknowledged On
Ringback Slow flash
Normal Off
Acknowledged On