Emerson Rosemount Xstream Series Instruction Manual page 178

X-STREAM
Each threshold may be configured to be OFF,
a LOW or a HIGH alarm, utilizing the "Function"
parameter:
Off: Alarm function deactivated, output level
is digital "LOW" all the time.
Low: The moment, the currently measured
concentration goes below the specified
level, an alarm signal is activated.
Alarm signal level is digital "HIGH".
High: The moment, the currently measured
concentration goes above the specified
level, an alarm signal is activated.
Alarm signal level is digital "HIGH".
In addition the "Function" parameter supports
the fail-safe operation mode:
Fail-Safe means an activated alarm gives a
digital "LOW" level signal instead of a "HIGH"
level signal:
Off FS: Alarm function deactivated, output level
is digital "HIGH" all the time.
Low FS: The moment, the currently measured
concentration goes below the specified
level, an alarm signal is activated.
Alarm signal level is digital "LOW".
High FS: The moment, the currently measured
concentration goes above the specified
level, an alarm signal is activated.
Alarm signal level is digital "LOW".
Note!
"Function" parameter factory setting is Off FS
(fail-safe) unless otherwise specified at time
of order.
6-14
6-2 Checking the Instrument's Setup
Combining the different modes with setting
the threshold levels in a proper way gives
the operator the choice of programming diffe-
rent behaviours:
• Window mode: If the concentration
exceeds the limits defining a concentra-
tion window, an alarm is activated.
High and high-high alarms: This mode
•
allows to set a prealarm level and a main
alarm level for increasing concentrations
Low and low-low alarms: This mode allows
•
to set a prealarm and a main alarm for
decreasing concentrations.
Refer to the following paragraphs and figures
for detailed information on alarm settings!
Emerson Process Management GmbH & Co. OHG
Instruction Manual
HASAxE-IM-HS
05/2006