Danfoss VLT 2800 Design Manual page 83

Programming
When parameter 214 Reference function is set to [1]
Relative, the defined Preset references (par. 215-218) are
added as a percentage of the total of the present external
references. If terminal 53 is applied to an analogue input
voltage of 4 V, the resulting reference is:
Parameter 214 Reference function =[1] Relative :
Parameter 204 Minimum reference
Reference effect at 4 V
Parameter 215 Preset reference
Resulting reference
Illustration 4.11 shows the resulting reference in relation to
the external reference, which varies from 0-10 V. Parameter
214 Reference function is set to [0] Sum and [1] Relative.
Illustration 4.11 also shows parameter 215 Preset reference 1
is programmed to 0 %.
Illustration 4.11 Resulting Reference vs. External Reference
214 Reference function
Value:
Sum (sum)
Relative (relative)
External/preset (external/preset)
Function:
It is possible to define how to add preset references to the
other references; for this purpose, use [0] Sum or [1]
Relative. It is also possible by using the [2] External/preset
to select whether a shift between external references and
preset references is required.
External reference is the sum of the analog references,
pulse references and any references from serial communi-
cation.
Description of choice:
If [0] Sum is selected, one of the adjusted preset references
(parameters 215-218 Preset reference) is summarised as a
percentage of the reference range (Ref
to the other external references.
MG27E402
Design Guide
If [1] Relative is selected, one of the added preset
references (parameters 215-218 Preset reference) is
summarised as a percentage of the sum of present
external references.
If [2] External/preset is selected, it is possible via a digital
input to shift between external references or preset
references. Preset references is a percentage value of the
10.0 Hz
reference range.
16.0 Hz
NOTICE
2.4 Hz
If Sum or Relative is selected, one of the preset
28.4 Hz
references is always active. If the preset references are to
be without influence, they must be set to 0% (factory
setting).
215
216
217
218
Value:
-100.00% - +100.00%
of the reference range/external reference
Function:
4 different preset references can be programmed in
parameters 215-218 Preset reference.
The preset reference is stated as a percentage of the
reference range (Ref
other external references, depending on the selection
made in parameter 214 Reference function. Select the preset
references via the digital inputs or via serial communi-
cation.
Preset ref., msb
Table 4.1 Preset Reference Selection
[0]
[1]
Description of choice:
[2]
Set the preset reference(s) that is/are to be the options.
219
Value:
0.00 - 100% of the given reference
Function:
In this parameter, the percentage value can be set which is
either added to or deducted from the remote-controlled
references.
The remote-controlled reference is the sum of preset
references, analog references, pulse reference and any
references from serial communication.
Description of choice:
- Ref ), added
MIN MAX
If Catch up is active via a digital input, the percentage
value in parameter 219 Catch up/Slow down reference is
added to the remote-controlled reference.
Danfoss A/S © Rev. May/2014 All rights reserved.
Preset reference 1 (PRESET REF. 1)
Preset reference 2 (PRESET REF. 2)
Preset reference 3 (PRESET REF. 3)
Preset reference 4 (PRESET REF. 4)
- Ref ) or as a percentage of the
MIN MAX
Preset ref. lsb
0 0
0 1
1 0
1 1
Catch up/Slow down reference
4 4
0.00%
Preset ref. 1
Preset ref. 2
Preset ref. 3
Preset ref. 4
0.00%
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