Device Output Configuration; Pv Range Values; Process Variable Damping - Emerson Rosemount 3144P Reference Manual

Reference Manual
00809-0100-4021, Rev AA
March 2002
Device Output
Configuration
12. Select 3 Drift Damping to enter a drift alert damping value. This value
must be between 0 and 32 seconds.
13. Select 1 Drift Alert Option and select Enable Alarm or Warning only.
14. Select SEND to download the alarm setting to the transmitters.
NOTE
Enabling Drift Alert Option Warning only (Step 13) will set a flag (via HART)
whenever the maximum acceptable difference between Sensor 1 and Sensor
2 has been exceeded. If it is desired for the the transmitter's analog signal to
go into alarm when Drift Alert is detected, select Alarm in Step 13. The Drift
Alert alarm cannot be enabled when Hot Backup is enabled; The Drift Alert
alarm can only be enabled if Hot Backup is enabled.
Device output configuration contains PV range values, alarm and saturation,
HART output, and LCD meter options.

PV Range Values

HART Fast Keys 1, 3, 4, 1
The PV URV and PV LRV commands, found in the PV Range Values menu
screen, allow the user to set the transmitter's lower and upper range values
using limits of expected readings. See Table A-2 on page A-5 for unit and
range setting limits. The range of expected readings is defined by the Lower
Range Value (LRV) and Upper Range Value (URV). The transmitter range
values may be reset as often as necessary to reflect changing process
conditions. From the PV Range Values screen select 1 PV LRV to change the
lower range value and 2 PV URV to change the upper range value.
Reranging the transmitter sets the measurement range to the limits of the
expected readings. Setting the measurement range to these limits maximizes
transmitter performance; the transmitter is most accurate when operated
within the expected temperature range for the application.
The rerange functions should not be confused with the trim function. Although
reranging the transmitter matches a sensor input to a 4-20 mA output, as in
conventional calibration, it does not affect the transmitter's interpretation of
the input.

Process Variable Damping

HART Fast Keys 1, 3, 4, 1, 3
The PV Damp command changes the response time of the transmitter to
smooth variations in output readings caused by rapid changes in input.
Determine the appropriate damping setting based on the necessary response
time, signal stability, and other requirements of the loop dynamics of the
system. The default damping value is 5.0 seconds and can be reset to any
value between 0 and 32 seconds.
The value chosen for damping affects the response time of the transmitter.
When set to zero (i.e., disabled), the damping function is off and the
transmitter output reacts to changes in input as quickly as the intermittent
sensor algorithm allows. Increasing the damping value increases transmitter
response time.
Model 3144P
3-17