Emerson Rosemount, Reference Manual

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159
Reference Manual
00809-0100-4021, Rev GC
Section 4: F
OUNDATION
fieldbus Configuration
April 2014
Foundation™ fieldbus configuration
12. Go to OUT_SCALE.
a. Choose UNITS_INDEX to be °F.
b. Set the 0 and 100 scale to be the same as in step 4b.
13. Put the AI block back into Auto mode.
14. Follow Host Procedure to download schedule into block.
4.9.3 Filtering
Note
If damping has already been configured in the transducer block, setting a non-zero value for
PV_FTIME will add to that damping.
The filtering feature changes the response time of the device to smooth variations in output
readings caused by rapid changes in input. Adjust the filter time constant (in seconds) using the
PV_FTIME parameter. To disable the filter feature, set the filter time constant to zero.
4.9.4 Process alarms
Process alarm detection is based on the OUT value. Configure the alarm limits of the following
standard alarms:

High (HIGH_LIM)

High high (HIGH_HIGH_LIM)

Low (LOW_LIM)

Low low (LOW_LOW_LIM)
To avoid alarm chattering when the variable is oscillating around the alarm limit, an alarm
hysteresis in percent of the PV span can be set using the ALARM_HYS parameter. The priority of
each alarm is set in the following parameters:

HIGH_PRI

HIGH_HIGH_PRI

LOW_PRI

LOW_LOW_PRI
Alarm priority
Alarms are grouped into five levels of priority.
Priority
number Priority description
0 The alarm condition is not used.
1
An alarm condition with a priority of 1 is recognized by the system, but is not reported
to the 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.