48
210 Reference Type (REF. FUNCTION)
Value:
Sum (SUM) [0]
Relative (RELATIVE) [1]
★ External/preset (EXTERNAL/PRESET) [2]
Function:
It is possible to define how the preset references are added to the other
references. For this purpose, Sum or Relative is used. It is also
possible, by using the External/Preset function, to select between the
external references and a preset reference.
Description of choice:
If Sum is selected, one of the preset references (parameters 211
through 214, Preset Reference) is added to the other external
references as a percentage of the reference range (minimum reference
through maximum reference).
If Relative is selected, one of the adjusted preset references (param-
eters 211 through 214, Preset Reference) is added as a percentage of
the total external reference.
If External/Preset is selected, it is possible to shift between the external
references and the preset references using terminals 16, 17, 29, 32 or
33 (parameters 300, 301, 305, 306 or 307, Digital Inputs). Preset
references are a percentage value of the reference range. External
reference is the sum of the analog references, pulse references and
any references from serial communication.
NOTE
If Sum or Relative is selected, one of preset
references is always active. If preset references
are not used, set value to 0%.
NOTE
See Calculation of Resulting Reference section
in this manual for mathematic formula to
calculate references.
Reference Type
The example below shows how the resulting reference is calculated
when Preset references are used together with Sum and Relative
references set in parameter 210, Reference Type. A formula for
calculating the resulting reference is given under Calculation of
Resulting Reference. See the drawing under Reference Handling.
Example:
The following parameters have been set:
Parameter 204 Minimum Reference: 10 Hz
Parameter 205 Maximum Reference: 60 Hz
Parameter 211 Preset Reference: 15%
Parameter 308 Terminal 53, Analog Input: Reference
Parameter 309 Terminal 53, Min. Scaling: 0 V
Parameter 310 Terminal 53, Max. Scaling: 10 V
When parameter 210 Reference Type is set to Sum, one of the
adjusted Preset References, parameters 211 through 214, will be
added to the external references as a percentage of the reference
range. If terminal 53 has an analog input voltage of 4 V, the resulting
reference will be:
Parameter 210 Reference type = Sum
Parameter 204 Minimum Reference = 10.0 Hz
Reference contribution at 4 V = 16.0 Hz
Parameter 211 Preset Reference
= 6.0 Hz
Resulting reference = 32.0 Hz
If parameter 210 Reference Type is set to Relative, one of the adjusted
Preset References parameters 211 through 214 will be totaled as a
percentage of the sum of the present external references. If terminal 53
has an analog input voltage of 4 V, the resulting reference will be:
Parameter 210 Reference type = Relative
Parameter 204 Minimum Reference = 10.0 Hz
Reference contribution at 4 V = 16.0 Hz
Parameter 211 Preset Reference = 2.4 Hz
Resulting reference = 28.4 Hz
The graph in the next column shows the resulting reference while the
external reference changes from 0 to 10 V. Parameter 210, Reference
Type has been programmed for Sum and Relative. Parameter 211,
Preset Reference 1, is programmed for 0%.
✭ Indicates factory default setting. Numbers in brackets [ ] represent selection as displayed on the serial bus.
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