9
Reference Manual
00809-0100-4808, Rev DA
Transmitter Functions
October 2016
Transmitter Functions
2.8
Check output
Before performing other transmitter online operations, review the digital output parameters to ensure
that the transmitter is operating properly and is configured to the appropriate process variables.
2.8.1
Process variables
The process variables for the Rosemount 3051N Transmitter provide the transmitter output, and are
continuously updated. The process variable menu displays the following process variables:
Pressure
Percent of Range
Analog Output
The pressure reading in both Engineering Units and Percent of Range will continue to track with
pressures outside of the defined range from the lower to the upper range limit of the sensor module.
Note
Regardless of the range points, the Rosemount 3051N Transmitter will measure and report all readings
within the digital limits of the sensor. For example, if the 4 and 20 mA points are set to 0 and 10 in H
2
O
on a range code 1 Rosemount 3051N Transmitter, and the transmitter detects a pressure of 25 inH
2
O, it
digitally outputs the 25 inH
2
O reading and a 250% of span reading. However, there may be up to ±5.0%
error associated with output outside of the range points.
2.8.2
Sensor temperature
The Rosemount 3051N Transmitter contains a temperature sensor just above its pressure sensor in the
sensor module. When reading this temperature, keep in mind that this is not a process temperature
reading.
2.9
Basic setup
2.9.1
Set process variable units
The
PV Unit
command sets the process variable units to allow you to monitor your process using the
appropriate units of measure. Select from the following engineering units:
HART Fast Keys
2
HART Fast Keys
1, 1, 4
HART Fast Keys
1, 3, 2
inH
2
O
mmHg
bar
Pa
inHg
psi
mbar
kPa
ftH
2
O
torr
g/cm
2
atm
mmH
2
O
inH
2
O at 4 °C
kg/cm
2
mmH
2
O at 4 °C