Emerson Rosemount 644 FOUNDATION Reference Manual page 23

Reference Manual
00809-0400-4728, Rev CA
Alarm priority
Alarms are grouped into five levels of priority:
Priority
number
Status options
Status options (STATUS_OPTS) supported by the AI block are shown below.
Propagate fault forward
If the status from the sensor is Bad, Device failure or Bad, Sensor failure, propagate it to OUT without
generating an alarm. The use of these sub-status in OUT is determined by this option. Through this
option, the user may determine whether alarming (sending of an alert) will be done by the block or
propagated downstream for alarming.
Uncertain if limited
Set the output status of the Analog Input block to uncertain if the measured or calculated value is
limited.
BAD if limited
Set the output status to Bad if the sensor is violating a high or low limit.
Uncertain if Man mode
Set the output status of the analog input block to uncertain if the actual mode of the block is Man.
Note
The instrument must be in Out of Service mode to set the status option.
Advanced features
The AI Function Block provides added capability through the addition of the following parameters:
ALARM_TYPE
ALARM_TYPE allows one or more of the process alarm conditions detected by the AI function block to be
used in setting its OUT_D parameter.
OUT_D
OUT_D is the discrete output of the AI function block based on the detection of process alarm
condition(s). This parameter may be linked to other function blocks that require a discrete input based
on the detected alarm condition.
Configuration
Priority description
0 The alarm condition is not used.
An alarm condition with a priority of 1 is recognized by the system, but is not reported to the
1
operator.
2 An alarm condition with a priority of 2 is reported to the operator.
3–7 Alarm conditions of priority 3 to 7 are advisory alarms of increasing priority.
8–15 Alarm conditions of priority 8 to 15 are critical alarms of increasing priority.
Configuration
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