12
Reference Manual
00809-0100-4808, Rev DA
Transmitter Functions
October 2016
Transmitter Functions
To rerange the transmitter using the span and zero buttons, perform the following procedure.
1. Loosen the screw holding the label on top of the transmitter housing, and rotate the label to expose
the zero and span buttons (see
Figure 2-6 on page 12
).
2. Using a pressure source with an accuracy three to ten times the desired calibrated accuracy, apply a
pressure equivalent to the lower range value to the high side of the transmitter.
3. To set the 4 mA point, press and hold the zero button for at least two seconds, then verify the output
is 4 mA. If a meter is installed, it will display ZERO PASS.
4. Apply a pressure equivalent to the upper range value to the high side of the transmitter.
5. To set the 20 mA point, press and hold the span button for at least two seconds, then verify the
output is 20 mA. If a meter is installed, it will display SPAN PASS.
Note
If the transmitter security jumper is in the
ON
position, or if the local zero and span adjustments are
disabled through the software, adjustments to the zero and span cannot be made using the local
buttons. Refer to
Figure 2-1 on page 5
for the proper placement of the transmitter security jumper. Or
refer to
“Local span and zero control (local keys)” on page 13
in Section 2 for instructions on how to
enable the span and zero buttons.
Figure 2-6. Local Zero and Span Adjustments
A. Span and Zero Adjustment buttons
After reranging the transmitter using the span and zero adjustments, it is possible to disable the
adjustments to prevent further reranging. Refer to
“Local span and zero control (local keys)”
below for
more information.
2.9.7
Damping
The process variable (PV)
Damp
command changes the response time of the transmitter to smooth
variations in output readings caused by rapid changes in input. Determine the appropriate damping
setting based on the necessary response time, signal stability, and other requirements of the of loop
dynamics of your system. The default damping value is 0.4 seconds,
(1)
and can be reset to any of eleven
pre-configured, nominal damping values between 0 and 25.6 seconds.
HART Fast Keys
1, 3, 6
1.
Rosemount 3051ND0 default damping is 3.2 seconds. Rosemount 3051ND1, with calibrations below 2.5 inH
2
O (0,62 kPa), have damping set at 3.2 sec-
onds.
A