User manual

36
© 2006, Elektro-Automatik GmbH & Co. KG
Irrtümer und Änderungen vorbehalten
EN
Instruction Manual
EL 3000 A Series
Date: 09-09-2013
6.7.2 Level B
When switching to „Level B“ with the selector Level
Control(3), the set values of Level B become active. This
mode works the same way as Level A.
In Level B mode, the load can be switched to remote
control from a PC and via the interface, in order to control
and monitor it like during manual operation.
When changing to remote control the currently selected
Level Control setting is kept.
6.7.3 Level A/B (pulsed operation)
This mode combines two set values A and B with two
seperately adjustable pulse widths for A and B. The elec-
tronic load generates automatic set value leaps between
A and B with those values. The rise/fall time is also ad-
justable. This pulsed operation is only applied to the set
value which belongs to the selected MODE, means in CV
the voltage is affected etc. The other set values remain
constant. Also see Figure 11 and Figure 12.
The pulse width of A is dedicated to the set value of A etc.
The sum of the pulse widths results in a period t, which
represent a certain frequency f=1/t. The pulse widths are
adjustable from 50µs...100s which results in a period
of 100µs...200s, which corresponds to a frequency of
10kHz...0.005Hz.
Note: Alarms like OVP or PF (power fail) (see section 6.1,
item „Alarm management“) which switch off the input also
stop the pulsed operation. It can be resumed as soon as
all alarms are gone and have been acknowledged.
External trigger
The external switchover between A and B, realised with
the trigger input on the analogue interface, is only availab-
le in Level A/B mode. The trigger input has to be activated
in the setup menu with the option Trigger mode (see
„7.Deviceconguration“. The default setting is internal.
By setting it to external the switchover between A and B
can only be done via the trigger input.
Handling the device
The adjusted rise/fall time is still effective here, but the pul-
se widths are now determined by the trigger signal, which
is fed into the trigger input. The trigger signal must be
square wave, for levels see „8. The analogue interface“.
As long as external trigger is active the pulse times of A
and B are not indicated in the display and are also not
adjustable anymore. The display indicates the condition
as „Ext. trigger“.
The rotary knob Selection(5) is used to select the set
values for A and B, as well as both pulse times, and
Setting(6) is used to change them. The display shows
the letters A and B to indicate the assignment. When
navigating between the set values, an arrow (->) is placed
in front of the currently selected one. A rise/fall time for
the pulsed operation is also adjustable. Both, rise and fall
time, are identical and can‘t be set seperately for A and
B.Itisdisplayedasslopeintheformat∆value/∆time,like
forexampleingure10with60A/20ms.
The Level A/B operation is started as soon as the load
input is set to on.
Figure 11
Note: during Level A/B operation following applies: the
set value of A must always be greater than or equal to
B. Thus you can adjust A downwards only to the value
of B and B upwards only to the level of A. If it seems that
Level A is not adjustable somehow this might be caused
by Level B being the same value.
Figure 9. Normal load operation in CP regulation mode
Figure 10. Level A/B operation with pulse width adjustment