User Manual

Page 56
ELR 9000 Series
www.elektroautomatik.de
[e-mail]
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
3.8 The function generator
3.8.1 Introduction
The built-in function generator is, like the equally named electronic devices, able to create various signal forms
and apply these to set values for voltage or current.
Whilst R/I mode is activated, access to the function generator is not available.
The generator functions can be manually operated completely on the device. In remote control, only the customis-
able arbitrary generator and a XY function are available, which can be congured and controlled via digital com-
munication. The arbitrary generator can replicate all manually serviceable functions, except UI and IU For UI/IU,
the XY function is assigned.
The following functions are retrievable, congurable and controllable:
Function Usable
on
Short description
Sine wave U, I Sine wave generation with adjustable amplitude, offset and frequency
Triangle U, I Triangular wave signal generation with adjustable amplitude, offset, gain and decay times
Rectangular U, I Rectangular wave signal generation with adjustable amplitude, offset and duty cycle
Trapezoid U, I Trapezoidal wave signal generation with adjustable amplitude, offset, rise time, pulse
time, fall time, idle time
DIN 40839 - Simulated automobile engine start curve according to DIN 40839 / EN ISO 7637, split
into 5 curve sequences, each with a start voltage, nal voltage and time
Arbitrary U, I 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 U, I Generation of a linear rise or fall ramp with start and end values and time before and
after the ramp
UI-IU - Table (.csv) with values for U or I, uploaded from a USB ash drive
3.8.2 General
3.8.2.1 Resolution of X (Time) and Y (Amplitude)
The device can set 4096 steps between 0 ... 100% of nominal value. The intervals to create a linear or other rise/
fall are calculated depending on the amplitude and then set.
If the amplitude is very low and the time long, only few intervals will be set as otherwise many identical values will
be set one after another, generating a staircase effect.
3.8.3 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, including in function generator mode,always with the three set values U,I and P.
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 10V is applied to the DC input and a sine wave function should operate on
the current with an amplitude of 20A and offset 20A, then the function generator will create a sine wave progres-
sion of current between 0A (min) and 40A (max), which will result in an input power between 0W (min) and 400W
(max).The input power, however, is limited to its set value. If this were 300W then, in this case, the current would
be limited to 30A and, if clamped to an oscilloscope, it would be seen to be capped at 30A and never achieve the
target of 40A.
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.