Transmitter Overview - Emerson Rosemount 2051 Reference Manual

Section 1: Introduction
April 2013
1.4

Transmitter overview

The Rosemount 2051C Coplanar design is offered for Differential Pressure (DP) and Gage
Pressure (GP) measurements. The Rosemount 2051C utilizes capacitance sensor technology for
DP and GP measurements. The Rosemount 2051T utilizes piezoresistive sensor technology for
AP and GP measurements.
The major components of the Rosemount 2051 are the sensor module and the electronics
housing. The sensor module contains the oil filled sensor system (isolating diaphragms, oil fill
system, and sensor) and the sensor electronics. The sensor electronics are installed within the
sensor module and include a temperature sensor, a memory module, and the analog to digital
signal converter (A/D converter). The electrical signals from the sensor module are transmitted
to the output electronics in the electronics housing. The electronics housing contains the
output electronics board, the optional external configuration buttons, and the terminal block.
The basic block diagram of the Rosemount 2051CD is illustrated in
For the Rosemount 2051, pressure is applied to the isolating diaphragm(s). 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 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 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 2 buttons mounted on the front of the display board.
See Figure
Figure 1-2. LCD/LOI Display
4
1-2.
LCD Display
Reference Manual
00809-0100-4107, Rev BA
Figure 1-3 on page
LOI Display
5.
Introduction