User manual

Page 45
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
EL 3000 B Series
3.9 The function generator
3.9.1 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.
The functions are based on an ramp generator anddirectlyaccessibleandcongurableusingmanualcontrol.For
remotecontrol,thedesiredfunctionruncanbeconguredusingseveralsetupparameters.Thefunctions“Battery
test” and “MPP tracking” are not based on this generator.
Thefollowingfunctionsareretrievable,congurableandcontrollable:
Function Short description
Triangle Triangular wave signal generation with adjustable amplitude, offset, rise and fall times
Rectangular Rectangular wave signal generation with adjustable amplitude, offset and pulse/pause time
Trapezoid Trapezoidal wave signal generation with adjustable amplitude, offset, rise time, pulse time, fall
time, idle time
Ramp Generation of a linear rise or fall ramp with start value, end value and rise/fall time
Battery test Battery discharge test with constant or pulsed current, along with Ah, Wh and time counters
MPP Tracking Simulationofthecharacteristictrackingbehaviourofsolarinverterswhenseekingtondthe
maximum power point (MPP) when being connected to typical sources such as solar panels
3.9.2 General
3.9.2.1 Resolution
Amplitudes generated by the arbitrary generator have an effective resolution of approx. 3277 steps. If the amplitude
is very low and the time long, the device would generate less steps and set multiple identical values after another,
generating a staircase effect. It is furthermore not possible to generate every possible combination of time and a
varying amplitude (slope).
3.9.3 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. That means, if, e.g. a voltage of 10 V is applied to the DC input and a rectangle function should operate on
the current with an amplitude of 20 A and offset 20 A, then the function generator will create a rectangular 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 300 W then, in this case, the
current would be limited to 30 A and, if clamped to an oscilloscope, it would be seen to be capped at 30 A and
never achieve 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, as the voltage regulation
limits down to 0 with an electronic load, other than current or power. The correct settings for each of the other set
values is therefore essential.
3.9.4 Manual operation
3.9.4.1 Function selection and control
Via the touchscreen one of the functions listed in 3.9.1 can be called
up,conguredandcontrolled.Selectionandcongurationareonly
possible when the input is switched off.
► How to select a function and adjust parameters
1. While the DC input is switched off, press button .
2. In the menu navigate to “Function Generator”withthearrowbuttons(↓,↑)andpress again.