User manual

Tips
Using the Independently Floating Isolated Inputs
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Using the Independently Floating
Isolated Inputs
You can use the independently floating isolated inputs to
measure signals that are independently floating from each
other.
Independently floating isolated inputs offer additional
safety and measurement capabilities compared to inputs
with common references or grounds.
Measuring Using Independently Floating Isolated
Inputs
The test tool has independently floating isolated inputs.
Each input section (A, B, C and D) has its own signal input
and its own reference input. The reference input of each
input section is electrically isolated from the reference
inputs of the other input sections. The isolated input
architecture makes the test tool about as versatile as
having four independent instruments. The advantages of
having independently floating isolated inputs are:
• It allows simultaneous measurement of independently
floating signals.
• Additional safety. Since the commons are not directly
connected, the chance of causing short circuit when
measuring multiple signals is greatly reduced.
• Additional safety. When measuring in systems with
multiple grounds, the ground currents induced are
kept to a minimum.
Because the references are not connected together inside
the test tool, each reference of the used inputs must be
connected to a reference voltage.
Independently floating isolated inputs are still coupled by
parasitic capacitance. This can occur between the input
references and the environment, and between the input
references mutually (see Figure 34). For this reason, you
should connect the references to a system ground or
another stable voltage. If the reference of an input is
connected to a high speed and / or high voltage signal,
you should be aware of parasitic capacitance. (See Figure
34 , Figure 36, Figure 37 and Figure 38.)
Note
The input channels are electrically isolated from
the USB port and from the power adapter input.