Page 65
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
PSI 9000 15U/24U Series
3.10.10
Arbitrary function
The arbitrary (freely definable) function offers the user further scope. There are 99 sequence points available for
use for current I and voltage U, all of which have the same parameters but which can be differently configured
so that a complex function process can be built up. The 99 points can run one after another in a sequence block,
and this sequence block can then be repeated many times or endlessly. From the 99 points a block can be freely
defined to run from point x to point y. A sequence point or sequence point block acts only on current or voltage,
thus a mix of assignment to current I or voltage U is not 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 is allocated a sequence time in which the AC/
DC curve from start to finish will be generated.
The following parameters can be configured for each sequence point in the arbitrary function. The table shows
some 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 sine wave part of the curve
Ie(AC)
0...50% Nominal value of I
End amplitude of the sine wave part of the curve
fs(1/T)
0 Hz...1000 Hz
Start frequency of the sine wave part of the curve
fe(1/T)
0 Hz...1000 Hz
End frequency of the sine wave part of the curve
Angle
0°...359°
Start angle of the sine wave 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 0.1 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. A minimal change
over an extended time is not possible and in such a case the device will report an inapplicable
setting.
After the settings for the selected sequence point are accepted with SAVE, further sequence points can be con
-
figured. If the button NEXT is touched a second settings screen appears in which global settings for all 99 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 block
End seq.
Start seq...99
Last sequence point in the block
Seq. Cycles ∞ or 1...999
Number of cycles of the block.
Schematic diagram:
Applications and results:
St
ar
t(
D
C
)
t
A
St
art
(A
C)
Seq.time
En
d
(D
C
)
Example 1
Focussing 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 time
and the frequency. If the sequence 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.
