Reference Manual
00809-0100-4360, Rev BA
August 2008
Rosemount 1151
3-12
From 0.0 percent to 0.6 percent of the ranged pressure input, the slope of the
curve is unity (y = x). This allows accurate calibration near zero. Greater
slopes would cause large changes in output for small changes at input. From
0.6 percent to 0.8 percent, the slope of the curve equals 42 (y = 42x) to
achieve continuous transition from linear to square root at the transition point.
Setting Damping
The Rosemount 1151 Smart Pressure Transmitter has electronic damping
that can increase the response time of the transmitter to smooth the output
when there are rapid input variations. High damping values filter out process
noise, but response time is decreased. Low damping values increase
response time, but process noise can also be detected.
For Rosemount 1151 Smart Pressure Transmitter transmitters, damping
values may be set in 0.1 second increments from 0 to 16.0 seconds. The
default damping value is 0.2 seconds (0.4 seconds for Range 3). Damping
values for inert-filled sensors are slightly higher.
Advanced Functions Burst Mode
When the Rosemount 1151 Smart is configured for burst mode, it provides
faster digital communication from the transmitter to the control system by
eliminating the time required for the control system to request information
from the transmitter.
Burst mode is compatible with use of the analog signal. Because HART
protocol features simultaneous digital and analog data transmission, the
analog value can drive other equipment in the loop while the control system is
receiving the digital information. Burst mode applies only to the transmission
of dynamic data (pressure and temperature in engineering units, pressure in
percent of range, and/or analog output in mA or V), and does not affect the
way other transmitter data is accessed.
Access to information other than dynamic transmitter data is obtained through
the normal poll/response method of HART communication. A HART-based
communicator or the control system may request any of the information that is
normally available while the transmitter is in burst mode. Between each
message sent by the transmitter, a short pause allows the HART-based
communicator or a control system to initiate a request. The transmitter will
receive the request, process the response message, and then continue
“bursting” the data approximately three times per second.
Saving, Recalling, and Cloning Configuration Data
Data that was entered off-line can be stored in the HART-based
communicator memory and downloaded to other transmitters later. Data also
can be copied from a transmitter in order to be sent to other transmitters in a
process known as “cloning.” This is especially useful if when working with a
large number of transmitters that require the same configuration data.
NOTE
The HART Communicator requires the use of the Transfer Menu to move data
between the transmitter memory and the communicator. This menu is
available from the Main Menu of the HART Communicator.
HART Comm. Fast Key Sequence 1, 3, 6
HART Comm. Fast Key Sequence 1, 4, 3, 3, 3
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