User manual

Page 50
EL 9000 T Series
www.elektroautomatik.de
[e-mail]
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
3.10 The function generator
3.10.1 Introduction
The built-in function generator (short: FG) is able to create various signal forms and apply these to the set value
of voltage or current.
All standard functions are based on the also available arbitrary generator. During manual control, the standard
functions such as sine wave can be selected and uses separately. In remote control, they are represented by sev-
eralsequencesandconguredwith8parameterseach.Someofthevaluesondisplayarenotdirectlyavailable
to be read via the digital interfaces, but can be obtained by reading other values and do corresponding calculation.
Thefollowingfunctionsareretrievable,congurableandcontrollable:
Function Short description
Sine wave Sine wave generation with adjustable amplitude, offset and frequency
Triangle Triangular wave signal generation with adjustable amplitude, offset, gain and decay times
Rectangular Rectangular wave signal generation with adjustable amplitude, offset and duty cycle
Trapezoid Trapezoidal wave signal generation with adjustable amplitude, offset, rise time, pulse time, fall
time, idle time
Arbitrary Generationofaprocesswithupto100freelycongurablesteps,eachwithastartandendvalue
(AC/DC), start and end frequency, phase angle and total duration
Ramp Generation of a linear rise or fall ramp with start and end values and time before and after the ramp
Battery test Battery discharge test with constant or pulsed current, along with Ah, Wh and time counters
With R/I being activated, access to the function generator is not available.
3.10.2 General
3.10.2.1 Limitations
The function generator is not accessible, neither for manual access, nor for remote control, if
• resistance mode (R/I adjustment mode, also called UIR mode) is active.
3.10.3 Method of operation
In order to understand how the function generator works and how the value settings interact, the following should
be noted:
The device operates always with the three set values U,I and P, also in function generator mode.
The selected function can be used on one of the values U or I, the other two are then constants and have a limiting
effect, but are not set automatically to optimal value by the device.
That means, if, e.g. a voltage of 10 V is applied to the DC input and a sine wave function should operate on the
current with an amplitude of 20 A and offset 20 A, then the function generator will create a sine wave progression of
current between 0 A (min) and 40 A (max), which will result in an input power between 0 W (min) and 400 W (max).
The input power, however, is limited to its set value. If this were, for instance, 300 W then the current would be lim-
ited to 30 A and if clamped to an oscilloscope it would look like capped at 30 A and never reach the target of 40 A.
Another case is when working with a function which is applied to the input voltage. If here the static voltage is set
higher than the amplitude plus offset then at function start there will be no reaction, because the voltage regulation
limits downwards to 0 with electronic loads, other than current or power. The correct settings for each of the other
set values is therefore essential.