Emerson Rosemount 248 Reference Manual page 44

Section 3: Configuration
March 2014
Write protect
Fast Key sequence
The Write Protect command protects the transmitter configuration data from accidental or
unwarranted changes. To enable the write protect feature:
1.
2.
Note
To disable write protect on the Rosemount 248, repeat the procedure, replacing Enable WP with
Disable WP.
HART output
Fast Key sequence
The HART Output command allows the user to make changes to the multidrop address, initiate
burst mode, or make changes to the burst options.
Alarm and saturation
Fast Key sequence
The Alarm/Saturation command allows the alarm settings (Hi or Low) and saturation values to be
viewed and changed. To change the alarm values and saturation values, select the value to be
changed, either 2 Low Alarm, 3 High Alarm, 4 Low Sat., or 5 High Sat then enter the desired new
value, which must fall within the guidelines:



Example: The low alarm value has been set to 3.7 mA. Therefore, the low saturation level, S,
must be 3.8  S  3.9 mA.

Example: The high alarm value has been set to 20.8 mA. Therefore, the low saturation level, S,
must be 20.5  S  20.7 mA.
See "Failure mode" on page 14
Rerange
Reranging the transmitter sets the measurement range to the limits of expected readings which
maximizes transmitter performance; the readings are is most accurate when the transmitter is
operated within the expected temperature range for the application.
36
1, 2, 3
From the HOME screen choose 1 Device Setup, 2 Diag/Service, 3 Write Protect.
Choose Enable WP.
1, 3, 3, 3
1, 3, 3, 2
The low alarm value must be between 3.50 and 3.75 mA
The high alarm value must be between 21.0 and 23.0 mA
The low saturation level must be between the low alarm value plus 0.1 mA and 3.9 mA.
The high saturation level must be between 20.5 mA and the high alarm value minus 0.1
mA.
for Failure Mode considerations.
Reference Manual
00809-0100-4825, Rev CB
Configuration