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Manual RS.8A.N5.0 © Danfoss 10-007
m Version 3.11
Curve
This field is used to select 1 of the 4 curve tables
(Cf1 - Cf4).
Break
This field is used to select the break point being
set up on the curve (1 - 1).
Input
This field is for the Internally Scaled input value to
be used at the break point selected. The 'To use ='
value can be copied into this field by pressing ' '
and ' ' together. This field has a range of between
0 and 9999.
Output
This field is for the Output value at the Break Point/
Input value selected. This has a range of between
-999.9 and 999.9.
The table should be completed so that the Input readings increase in value. Any
reading below the first value or above the last value will return out of range
Output Values (OC/SC).
In order to set up a Table you will require either a Resistance box (for resistance
probes) or a Current Source (for Current Probes) plus the manufacturer's data
defining the Input/Output relationship of the probe. The method is described
for a Resistance probe, but it is the same for the Current case except that it is
necessary to put the Input 1 link in the 4-0 mA position before starting.
1. Select (up to) 1 Output (Resistance) values from the
manufacturer's data sheet which correspond to Input (e.g.
Temperature) values in the range you wish to measure. For
maximum accuracy these points should be distributed evenly
across the required range.
. Connect the Resistance Box across the Input No. 1 and C
terminals of the unit and set it to the lowest of your selected
Output values. When you do this you should see a value appear
in the 'To use =' field. This is the Internally Scaled version of the
resistance you have connected. Set the Break field to 1 and then
go to the Input field.
3. Next either manually enter the value displayed in the 'To use ='
field, or press the ‘ ‘ and ‘ ‘ keys together to copy it to the Input field.
4. Move to the Output field and enter the Output (e.g. Temperature) value
from your probe data corresponding to the Resistance value you set.
5. Move the Edit Box to the Break field again and increase its value by 1,
which will clear the Input and Output fields.
6. Set your next chosen Resistance value from the probe data and,
when the 'To use =' value has stabilised, repeat from step 3
until all your points have been entered.
Once all points have been entered, you can vary the resistance connected to
Input 1 and observe the effect in the Converted field. For a given resistance, this
value should now be the same as that shown in the manufacturer's probe data.
For 4-0 mA inputs the 'Input type' must be set to 'CURRENT', then the Input/
Output fields will change to 4 mA/0 mA. The curve table can now be set up.
For example, if a pressure sensor was being used which produced 4 mA at 0.1
bar and 0 mA at 30 bar, then simply add 0.1 to the 4 mA field and 30 to the 0
mA filed. Ensure the point set-up and jumper link on the input terminal is set to
4-0 mA.
When you have finished or to abandon the operation, press ‘
’ to return to
the Setup Menu.
Setting up a Curve Table
4-20 mA Set-up
