L-Card L-502-P-G-D-I, Руководство пользователя

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45
4.5: Necessary conditions for correct connection and correct settings of the input of the
ADC L-502.
X i
Y i
GND
L-502
Z1
U
Yi
GND
L-502
Z
U
Yi
GND32
X (Y )
i i
Дифференциальный ИН
и дифференциальны й. реж им L-502
X (Y )
j
j
GND2
GND1
Z2
X j
Y j
GND1
U
Yj
Отдалённы е однофазны е ИН и дифф. реж им L-502
Отдалённая группа однофазны х ИН
и реж им с “общ ей землёй” L-502
Дифф. ИН
X i
Y i
GND
L-502
U
GND
Z
U
Yi
U
Xi
Examples of connecting the ADC input are collected in the item
6.1
on page
59
.
4.5. Necessary conditions for correct connection and
correct settings of the input of the ADC L-502.
Simplified examples of connection of the ADC input are given in section
6.1
, however,
!
... If you do not take into account the electrical properties of the signal sources, wires
(cables) when using L-502 ADC connections, use the default L-502 program settings, then,
most likely, you will get a poor result. Why? What do you need to consider? – If you
answer below these questions, links to the Internet resources of the site
en.lcard.ru will be
used.
4.5.1. The physical causes of possible problems
Physical cause #1. The wide bandwidth of the ADC transmission in L-502 (of the order
of 10 MHz) can be not only a great advantage of the L-502 ADC (in the ability of the ADC to
qualitatively digitize the high-speed dynamic processes), but it can be a big problem if:
•
the signal source has an unlimitedly wide frequency band (much wider than the width
of the frequencies of the useful signal)
•
unscreened connection is applied (or the signal source itself has a significant area of
the unscreened surface), in a situation where electromagnetic fields in the frequency
Remote single-phase VS group
and "with common ground" mode L-502
Remote single-phase VS and diff. L-502 mode
Differential VS
and differential mode L-502
Diff. VS