16
Sequences
Summary
From the sequence tables shown later in the manual, it will be evident that an alarm occurring causes
a flashing visual indication with audible.
Mute is used to silence the audible only.
Acknowledge stops the flashing and audible.
Please note:- If a new alarm occurs on an already acknowledged system, the horn will re-sound and
the new alarm will flash in accordance with the selected sequence.
Reset will return the alarm to the normal off state only when the unit has been acknowledged and the
associated alarm contact has returned to normal.
First-up Sequences
When a group of alarms is initiated, it is often important to know which of them was the first to occur.
This is achieved by having the first-up alarm flashing in a different manner compared to the
subsequent alarms. Three different first-up sequences are available F0, F1, F2 as detailed below and
in the following sequence tables. First-up operation should be used with care with the auto-reset
sequence and non-latch sequence as momentary alarms can cause ambiguity.
F0 The standard mode adopted by RTK Instruments, which indicates the first-up alarm by flashing at
twice the rate of subsequent alarms.
F1 In this mode subsequent alarms appear in the acknowledged state, hence they do not flash. The
audible device does not operate when subsequent alarms occur, unless still operating from the
first alarm. The acknowledge pushbutton will reset the first-up indication.
F2 In this mode all subsequent alarms do not flash, they will however operate the audible device. The
acknowledge pushbutton will reset the first-up indication.
Automatic Reset
In this mode, any signal contact which returns to normal after the acknowledge pushbutton has been
pressed will automatically reset. If the alarm contact returns to normal prior to acknowledge the alarm
will reset immediately after the acknowledge pushbutton has been operated.
Non-latch Sequence (No lock-in)
In this mode alarms will automatically reset as soon as the signal input returns to the normal state. It is
therefore possible that a fleeting alarm will occur and return to the off state without operator
intervention. Whilst the alarm is in the abnormal state the operator can silence or acknowledge the
alarm in the normal way.
Reflash Feature
In the standard mode, when an alarm has occurred and the acknowledged pushbutton activated, any
further changes of state to the alarm contact will not affect the alarm window display. With reflash
enabled any alarm that returns to normal and re-occurs will re-initialise the window.
