Power/Digital Ground And Earth/Ground - Advantech TPC-xx51T-x3BE Series User Manual

Step E: Connect the I/O to the controller if needed.
Step F: Connect the V+ and V- of power supply to TPC system.
After completing steps A to F, you can supply power to the TPC system.
Note! Make sure all wires follow the installation guidelines or it may cause
issues.
Note! If you install a USB device or Mini PCIe card on the TPC system, please
double check the voltage between V- and earth/ground, if the voltage is
not almost equal with each other, we suggest to short V- and earth/
ground the wiring.
2.6

Power/Digital Ground and Earth/Ground

The purpose is to block all the external electrical interference on the chassis, and
prevent any possibility of bad grounding design that could cause electric shocks. This
is so called level 1 isolation which consumer PCs do not normally implement.
 TPC Chassis and Earth (Power pin3) are short,
 TPC Chassis and Power / Digital GND are OPEN
The TPC is and industrial grade product, designed to prevent external interference
and the possibility of electric shock. To complete the isolation design, we need to
consider the following:
 The Ethernet is isolated, a LAN connection will not impact the isolation design.
 For general USB devices, to solve EMI and ESD issues, they are designed as a
chassis and digital short. But the TPC prevents damage to USB devices, ESD
and EMI solutions are designed to use the Power GND as a vent path to ensure
Power GND and Chassis GND will not have potential difference abnormalities.
 For COM ports, since there are different COM port designs, long distance con-
nection causes voltage level differences between the two COM port chassis.So
the shell ground of the cable must be isolated to the signal digital ground.
In real cases, many customers may break the level 1 isolation by 3rd party Device or
cable design, in this situation, we need to consider making all the GND short (Power
GND/Digital GND/Earth GND), and ensure customers have good earth/GND connec-
tion.
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