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Issue 10/06
P0777
Parameter Description
Value x1 of DAC scaling
CStat:
CUT
P-Group: TERMINAL
Datatype: Float
Active: first confirm
Unit: %
QuickComm.: No
Min:
Def:
Max:
-99999.0
0.0
99999.0
Level
2
Defines x1 output characteristic in [%]. Scaling block is responsible for adjustment of output value defined in
P0771 (DAC connector input).
Parameters of DAC scaling block (P0777 ... P0781) work as follows:
Where:
Points P1 (x1, y1) and P2 (x2, y2) can be chosen freely.
Example:
The default values of the scaling block provides a scaling of:
P1: 0.0 % = 0 mA
P2: 100.0 % = 20 mA
Dependency:
Affects P2000 to P2002 (referency frequency, voltage, current) depending on which setpoint is to be
generated.
Note:
The DAC-linear characteristic is described by 4 coordinates, based on a two-point equation:
y - P0778 P0780 − P0778
=
x - P0777 P0779 − P0777
For calculations the point-gradient form (offset and gradient) is more advantageous:
y = m ⋅ x + y0
The transformation between these two forms is given by:
m=
P0780 − P0778
P0779 − P0777
y0 =
P0778 ⋅ P0779 − P0777 ⋅ P0780
≤ 200 %
P0779 − P0777
For scaling of the input the value of y_max and x_min has to be determined. This is done by the following
equations:
xmin =
P0780 ⋅ P0777 − P0778 ⋅ P0779
P0780 − P0778
y max = ( x max − x min) ⋅
P0780 − P0778
P0779 − P0777
MICROMASTER 420 Parameter List
6SE6400-5BA00-0BP0
59