Emerson Rosemount 3144P Reference Manual page 48

HART Commissioning
December 2019
desired reading for the application. Refer to
side cover for sensor wiring diagrams.
If using an LCD display for local indication, configure the meter to read the appropriate
variables by using
Average temperature
HART 5 Fast Keys
HART 7 Fast Keys
Field Communicator
The transmitter configured for dual-sensors can output and display the average
temperature of any two inputs. Use the following procedure with Traditional Fast Keys to
configure the transmitter to measure the average temperature:
Configure sensor 1 and sensor 2 appropriately. Select 1 Device Setup, 3 Configuration, 2
Sensor Configuration, 1 Change Type and Conn. to set the sensor type and number of wires
for sensor 1. Repeat for Sensor 2.
Note
This procedure configures the average temperature as the primary variable analog signal.
If this is not needed, assign the average temperature to the secondary, tertiary, or
quaternary variable.
If using an LCD display, configure it to read the appropriate variables using
options.
Note
If Sensor 1 and/or sensor 2 should fail while PV is configured for average temperature and
the Hot Backup feature is not enabled, the transmitter will go into alarm. For this reason, it
is recommended when PV is sensor average, that the Hot Backup feature be enabled when
dual-element sensors are used, or when two temperature measurements are taken from
the same point in the process. If a sensor failure occurs when the Hot Backup feature is
enabled, while PV is sensor average, three scenarios could result:
• If sensor 1 fails, the average will only be reading from sensor 2, the working sensor.
• If sensor 2 fails, the average will only be reading from sensor 1, the working sensor.
• If both sensors fail simultaneously, the transmitter will go into alarm and the status
available (via HART) states that both sensor 1 and sensor 2 have failed.
In the first two scenarios, the 4–20 mA signal is not disrupted and the status available to
the control system (via HART Protocol) specifies which sensor has failed.
First good configuration
HART 5 Fast Keys
HART 7 Fast Keys
48
LCD display options.
2, 2, 3, 3
2, 2, 3, 3
2, 2, 3, 2
2, 2, 3, 2
Figure 2-4, or inside the transmitter terminal-
Reference Manual
00809-0100-4021
LCD display
Rosemount 3144P