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EA Elektro-Automatik GmbH
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www.elektroautomatik.de
EL 9000 B 15U/24U Series
3.10.10
Arbitrary function
The arbitrary, i. e. freely definable function offers the user a wider scope. There are 99 freely configurable sequence
points available. While all have the same set of parameters, they can be configured differently so that a complex
function process can be created. The 99 sequence points or a part of them can run one after another in a sequence
point block and this block can then be repeated up to 999 times or infinitely. A sequence point or sequence point
block is always assigned to either current or voltage, thus a mix of assignment to current or voltage isn’t possible.
The arbitrary curve overlays a linear progression (DC) with a sine curve (AC), whose amplitude and frequency are
shaped between start and end values. If the start frequency (fs) = end frequency (fe) = 0 Hz, the AC values have
no impact and only the DC part is effective. Each sequence point is allocated a time in which the AC/DC curve
from start to finish will be generated.
The following parameters can be configured for each sequence in the arbitrary function (the table lists parameters
for current, for voltage it would be Us, Ue etc.):
Value
Range
Description
Is(AC)
0...50% Nominal value of I
Start amplitude of the AC part of the curve
Ie(AC)
0...50% Nominal value of I
End amplitude of the AC part of the curve
fs(1/T)
0 Hz...10000 Hz
Start frequency of the AC part of the curve
fe(1/T)
0 Hz...10000 Hz
End frequency of the AC part of the curve
Angle
0°...359°
Start angle of the AC part of the curve
Is(DC)
Is(AC)...(Nominal value - Is(AC)) of I
Start value of the DC part of the curve
Ie(DC)
Ie(AC)...(Nominal value - Ie(AC)) of I
End value of the DC part of the curve
Seq.time
0.01 ms...36000 s
Time for the selected sequence point
The sequence point time (seq. time) and the start and end frequency are related. The minimum
value for
Δ
f/s is 9.3. Thus, for example, a setting of fs = 1 Hz, fe = 11 Hz and Seq.time = 5 s
would not be accepted as
Δ
f/s is only 2. A seq. time of 1 s would be accepted, or, if the time
remains at 5 s, then fe = 51 Hz must be set.
The amplitude change between start and end is related to the sequence time. An arbitrarily small
change over an extended time isn’t possible. See section „3.10.2.3. Minimum slope / maximum
for more information.
After the settings for the selected sequence point are accepted with SAVE, further ones can be configured. If the
button NEXT is touched a second settings screen appears in which global settings for all points are displayed.
The following parameters can be set for the total run of an arbitrary function:
Value
Range
Description
Start seq.
1...End seq.
First sequence point in the sequence point block
End seq.
Start seq...99
Last sequence point in the sequence point block
Seq. cycles
∞ or 1...999
Number of cycles of the sequence point block.
After continuing with
NEXT
there are global set values to define as last part of the function generator setup.
Schematic diagram:
Applications and results:
Sta
rt (D
C)
t
U,I
Seq.time
En
d (
DC
)
Example 1
Focusing 1 cycle of 1 sequence point:
DC values for start and end are the same, also the AC amplitude.
With a frequency >0 a sine wave progression of the set value is
generated with a defined amplitude, frequency and Y shift (offset,
DC value at start and end)
The number of sine waves per cycle depend on the sequence point
time and the frequency. If the time were 1 s and the frequency 1 Hz,
there would be exactly 1 sine wave. If the time were 0.5 s at the same
frequency, there would only be a half sine wave.
