Raco Verbatim, Руководство пользователя

Страница: 225 / 246

Annunciator Sequences and Options
Verbatim Owner's Manual K-3
K.2 Clear On Return To Normal
(Automatic Reset)
This section describes annunciator sequence options that are variants of the
ANSI designation
A-1 (automatic reset with silence pushbutton). The main
distinction of these from the M-1 sequence is that the alarm state is
automatically reset when the channel enters the RTN state. The Verbatim
sequences in this category differ amongst themselves mainly in when this
RTN transition is allowed to occur.
The basic A-1 sequence is obtained by executing code 923 3 . Channel states
transit from normal to alarm when criteria violations persist for the trip delay.
The alarm state is then locked in until acknowledgment is made. If no phone
numbers are configured, then this transition happens automatically and
immediately (
A-1-5-6 ). Otherwise, operator action is required. The transition
from acknowledged back to normal happens via manual reset or expiration of
the alarm reset timer. It also happens whenever the criteria violation for an
acknowledged alarm returns to normal.
Designation A-1-4 is obtained by code 923 2 . This sequence differs from A-1
only in that the unacknowledged alarms are not locked in. All visual and
audible indications are automatically reset whenever the criteria violations
return to normal for the trip delay period.
A minor variant of A-1-4 is obtained by code 923 4 . Here, the indications for
an acknowledged alarm will not be reset until it has been reported once,
regardless of RTN status. Unacknowledged alarms will be reset completely
without any lock-in whatsoever.
The implementation of these A -designates involves one wrinkle. The check for
RTN condition is not performed continuously, but rather only at specific times.
Hence, changes that happen in the midst of a report may not be reflected in the
annunciator state until some time later.
K.3 Report Return To Normal (Ringback)
This section describes the annunciator sequence option that provides explicit
indications of RTN conditions. This is a variant of the
R-1-8
designation
(ringback with silence pushbutton and common ringback audible). There are
two differences between
R and M or A designations. First is that the RTN state
can be entered only from the acknowledged alarm state.
M
has no notion of
RTN at all, and A allows the transition at any time. Second is that R locks in
RTN states until acknowledged, whereas
A
immediately resets.