© EPS Stromversorgung in 2022, this information is subject to change without notice
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30000800_manual_psb_10000_4u_30kw_en_04
Schematic diagram:
Application and result:
U
(I)
sta
rt
t
U,I
t1
t2
U
(I)
End
This function generates a rising, falling or horizontally running ramp be-
tween the start and end values over time t2. Time t1 creates a delay be-
fore the ramp starts.
The function runs once and stops at the end value. To have a repeating
ramp, the Trapezoid function would have to be used instead (see
Important to consider are the static values of U or I which define the start
level before the ramp generation. It’s recommended that the correspond-
ing static value is set equal to value
Start
, unless the load at the DC output
(source mode) shall not be provided with a voltage before the actual start
of the ramp (time t1) or the external source shall not yet be loaded with a
current in sink mode. In that case the static value should be set to zero.
3.11.12
IU table function (XY table)
The IU function offers the user the possibility to set a DC current dependent on the voltage being present on the DC terminal.
This works in source (PS) or sink (EL) mode. The function is driven by a table with exactly 4096 values, which are distributed
over the range 0...125% U
Nom
of actual voltage on the DC terminal. However, because of the upper limit of 102% of the rated
current only the first 3342 values in the XY table are effective.
The table can either be uploaded from a USB stick through the front side USB port or via remote control (ModBus protocol
or SCPI). The function is defined as:
IU function:
I = f(U) -> the device works in CC mode (if source operation, then with a load in CV mode)
Upload of a table from a USB stick must use text files in CSV format (*.csv). Plausibility is checked when
loading, i.e. values not too high, number of values correct etc. which may abort loading when errors are
found.
The 4096 values in the table are only checked for size and count. If all the values were to be graphically
plotted into a curve it could include huge step changes in the current. This could lead to complications
for the connected load or source if, for example, the internal voltage measurement swings slightly so
that the current jumps back and forth between a few entries in the table which, in the worst case, could
be bounce between 0 A and the maximum current.
3.11.12.1 Loading IU tables from USB stick
The so-called IU tables can be loaded from a file via a standard
USB stick that is formatted in FAT32. In order to load the file, it
has to meet following specifications:
•
The file name always begins with IU (not case-sensitive)
•
The file must be a text file of type Excel CSV and must only
contain one column with exactly 4096 values without gaps
•
Values with decimal places must use decimal separator that
matches the selection in the general setting
Log file separator
format
, which also defines the decimal separator between dot
and comma (US default should be dot)
•
No value may exceed the rated current of the device model. For example, if you have a 420 A model, none of the 4096 values
must be higher than 420 A (the adjustment limits from the device’s front panel do not apply here)
•
The file(s) has/have to be put inside a folder named HMI_FILES in the root path of the stick
If these specifications are not met, the device won’t accept the file and put out an error message in the display. The USB stick
may contain multiple IU files with different names and list them for the selection of one.
