Emerson Rosemount 3051P, Reference Manual, Page: 17 / 110

7
Reference Manual
00809-0700-4001, Rev AA
Configuration
May 2017
Configuration
2.4 Transmitter overview
The Rosemount
™
3051P is offered for Gage Pressure (GP) and Absolute Pressure (AP) measurements.
The Rosemount 3051P utilizes piezoresistive sensor technology for AP and GP measurements.
The major components of the Rosemount 3051P In-Line are the sensor module and the electronics
housing. The sensor module contains the oil filled sensor system (isolating diaphragm, oil fill system and
sensor). The electronics board is located within the electronics housing. The electrical signals from the
sensor module are transmitted to the electronics board which contains the memory module and the
analog to digital signal converter (A/D converter). The signal is then converted to a 4–20mA analog
output signal or HART digital signal. The electronics housing contains the output electronics board, the
optional external configuration buttons, and the terminal block. The basic block diagram of the
transmitter is illustrated in
Figure 2-3 on page 8 .
When pressure is applied to the isolating diaphragm, the oil deflects the sensor which then changes its
capacitance or voltage signal. This signal is then changed to a digital signal by the Signal Processing. The
microprocessor then takes the signals from the Signal Processing and calculates the correct output of
the transmitter. This signal is then sent to the D/A converter, which converts the signal back to the
analog signal, then superimposes the HART signal on the 4–20 mA output.
An optional LCD display can be ordered that connects directly to the interface board which maintains
direct access to the signal terminals. The display indicates output and abbreviated diagnostic messages.
A glass display cover is provided. For 4-20 mA HART output, the LCD display features a two-line display.
The first line displays the actual measured value, the second line of six characters displays the
engineering units. The LCD display can also display diagnostic messages.
Note
LCD display utilizes a 5x6 character display and can display output and diagnostic messages. The LOI
display uses an 8x6 character display and can display output, diagnostic messages, and LOI menu
screens. The LOI display comes with two buttons mounted on the front of the display board. See
Figure 2-2 .
Figure 2-2. LCD/LOI display
LCD display LOI display