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Annunciator Sequences and Options
Verbatim Owner's Manual K-1
K
Annunciator Sequences and
Options
This appendix discusses Verbatim operations in the context of the ANSI/ISA-
S18.1 Annunciator Sequences and Specifications standard. It also describes the
options available for configuring the Verbatim to support a variety of sequence
models. This information will be useful for users needing calling sequences
different from the one discussed in Section 5.
Note that the ANSI specification uses slightly different terminology from that
used here and elsewhere in this manual. Hopefully, this won't cause much
confusion.
One concept central to this discussion is that of channel state . At any given
time every armed channel is in one of the following 5 states: normal, alarm,
acknowledged alarm, return to normal (RTN), acknowledged RTN . The precise
meaning of these terms will be clarified later on.
The term annunciator state is used here to describe the actions and indications
of the Verbatim . These include LED illumination,voice reporting and status
logging.
An annunciator sequence consists of specifying how transitions between the
channel states occur and how they impact the annunciator state. The Verbatim
supports three distinct types of annunciator sequences. These are each discussed
in the subsections below. The next several paragraphs discuss the properties
they all share in common.
The normal, alarm and RTN states are determined by comparing the channel's
value with the criteria settings. A transition into these states requires that the
condition persist for a time period referred to as the
alarm trip delay . This
provides hysteresis, or debouncing between the real-world signals and the
channel state.
The two acknowledged states are determined by operator actions.
Unacknowledged alarms and RTNs transit to the acknowledged states by
pressing keys on the front panel or entering DTMF tones over the phone.
The Verbatim gives visual indications for the state of each channel or group of
channels. If normal, the LED is OFF. When alarmed, the LED is blinking.
When acknowledged the LED is steady ON. The visual indications for the RTN
states are sequence dependent, and described later.