Magtek DynaWave, Инструкция по установке и эксплуатации

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2 - Electrical Integration
DynaWave| OEM Contactless NFC Module | Installation and Operation Manual
Page 16 of 39 ( D998200265-10 )
2.3 Grounding / ESD Protection
To guard against ground loops and to protect the device against electrostatic discharge (ESD), it is
important for the solution design to ground the device correctly by connecting it to the lowest impedance
return path available. MagTek strongly recommends checking whether the host’s communication ports
provide earth ground, and whether the cable carries that ground all the way to the port on the device. This
will help make an informed decision about proper grounding.
MagTek strongly recommends solution designs bring in earth ground to the device using
ONE AND ONLY ONE of the possible paths:

Bring in earth ground through the USB cable’s metal connector shell to the USB Device Port [J3] .
In this case, it is very important to make sure the host and cable carry earth ground all the way to the
device. If they do not, use a single-wire cable and ground the
UART Port [J6] as described below.

Bring in earth ground through pin 10 of the UART Port [J6] . This can be done using an O-ring
connector at the other end of the cable, to be mounted to the nearest available earth ground, such as an
earth grounded enclosure (see
Figure 2-1 ). If there is no enclosure, or if the enclosure does not
provide earth ground, use a custom harness to bring in earth ground from another source.
If it is not practical to connect earth ground using only one of the available paths (for example, if the
solution uses multiple shielded cables that provide earth ground from the host), the solution design must
ensure that every source of external earth ground is at the same electrical potential, to prevent damaging
ground loop currents from occurring.
Figure 2-1 - Cable Configurations for Earth Ground