Rosemount 248, Reference Manual

Page: 29 / 80

Reference Manual
00809-0100-4825, Rev BB
August 2005
3-5
Rosemount 248
Review Configuration
Data
Before operating the Rosemount 248 in an actual installation, review all of the
factory-set configuration data to ensure that it reflects the current application.
Review
When activating the Review function, scroll through the configuration data list
to check each process variable. If changes to the transmitter configuration
data are necessary, refer to “Configuration” below.
Check Output
Before performing other transmitter on-line operations, review the Rosemount
248 digital output parameters to ensure that the transmitter is operating
properly.
Process Variables
The Process Variables menu displays process variables, including sensor
temperature, percent of range, analog output, and terminal temperature.
These process variables are continuously updated. The primary variable is
the 4 –20 mA analog signal. The secondary variable is the transmitter
terminal temperature.
Configuration
The Rosemount 248 must be configured for certain basic variables in order to
be operational. In many cases, all of these variables are pre-configured at the
factory. Configuration may be required if the transmitter is not configured or if
the configuration variables need revision.
Variable Mapping
The Variable Mapping menu displays the sequence of the process variables.
When using the Rosemount 248 you can select 5 Variable Re-Map to change
this configuration. When the Select PV screen appears Snsr 1 must be
selected . Either Sensor 1 , Terminal Temperature , or not used can be selected
for the remaining variables. The primary variable is the 4–20 mA analog
signal.
Select Sensor Type
The Connections command allows selection of the sensor type and the
number of sensor wires to be connected. Select from the following sensors:
• 2-, 3-, or 4-wire Pt 100, Pt 200, Pt 500, Pt 1000 RTDs: α = 0.00385 Ω /°C
• 2-, 3-, or 4-wire Pt 100: α = 0.003916 Ω /°C
• 2-, 3-, or 4-wire Ni 120 nickel RTDs
• 2-, 3-, or 4-wire Cu 10 RTDs
• IEC/NIST/DIN Type B, E, J, K, R, S, T thermocouples
• DIN type L, U thermocouples
• ASTM Type W5Re/W26Re thermocouple
• –10 to 100 millivolts
• 2-, 3-, or 4-wire 0 to 2000 ohms
A complete line of temperature sensors, thermowells, and accessory
mounting hardware is available from Emerson Process Management.
Fast Key Sequence 1, 4
Fast Key Sequence 1, 1
Fast Key Sequence 1, 3, 1
Fast Key Sequence 1, 3, 2, 1, 1