The Interface Solution Experts
13
FDY
PC-Programmable Frequency
Transmitter and Display
Figure 10.
Trimming Parameters Tab
Programming the Trimming
Parameters
The
Trimming
tab includes
Sensor
(Input)
Trimming
,
Output Trimming
and
Loop Test
functions.
Sensor Trimming
Sensor Trimming increases the measured accuracy of
your transmitter by matching the reading of its actual
input to either a calibrated source or the master device
to which it is transmitting. This causes the FDY’s
process variable and output to match its input.
Most transmitters can only trim at the 0% and 100%
points of the scale, but the FDY can trim any point
along the scale. Note that one-point trimming applies
an offset to the sensor reading, while two-point
trimming applies both an offset and gain.
Before you attempt to trim the FDY, ensure that the
correct sensor is attached to the transmitter, then go to
the
Trimming
tab as shown at the left, and:
1. Select the
User
radio button under
Trim Mode
, then
answer
Yes
to the “Please confi rm that you want to do
this
”
prompt.
2. Select one or two trim points by clicking the
appropriate button under
Trim Points
.
3. Enter the value you want to trim into the
Set Value
box under
Point 1
and click
Set
. Apply the value you
entered in the
Set Value
section to the FDY. Click on
the
Trim Pt 1
button. This matches the signal from the
sensor to the fi rst point you selected.
4. If you selected two trim points, enter the second
value that you want to trim into the
Set Value
box
under
Point 2
and click
Set
. Then apply the value you
entered in the
Point 2
box to the FDY. Click on the
Trim
Pt 2
button. This matches the signal from the sensor to
the second point you selected.
5. You have now fi nished trimming your sensor and can
continue on to
Output Trimming
.
