IXXAT FlexRay CCM/ FRC-EP150, Руководство по оборудованию

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Copyright IXXAT Automation GmbH
FlexRay CCM Manual, Version 2.4
Connections
16
3.2 Shielding
The device distinguishes between the signal ground (CANx_GND, FLX_GND,
TRGx_GND), the supply ground (GND) and the housing ground (PE). Each inter-
face has its own ground potential, as the interfaces are galvanically isolated from
each other. Fig. 3-6 shows an overview of the shields and of the potentials of the
individual interfaces.
The shields of CAN1, CAN2, FlexRay, Trigger-input, Trigger-output and Ethernet
are connected to the housing ground (PE) via RC-circuits and a varistor (VDR). The
shield is connected to the individual grounds via RC- circuits. Fig. 3-7 shows the
schematic of these RC-circuits
The isolation voltage of the shield to the PE is max. 50 V DC.
The isolation voltage of the signal ground against the shield and against the
supply ground as well as against other interfaces is max. 100 V DC.
The shielding of the power connector is connected directly to PE. The ground of
the power connector is only connected to the housing (PE) via RC-circuits
PE is designed as a closed ring around the PCB and connected to the housing via
the screw points and with EMC spring contacts.
Signal
Ground
Shield
Signal
Shield
FLX_GND
PE
Signal
Shield
CAN1_GND
PE
Signal
Shield
CAN2_GND
PE
TRGO_GND
TRGI_GND
Masse
Shield
GND
PE
6,5 .. 50 V
Housing
Ground
Ground
Ground
Ground
Ground
FlexRay A
FlexRay B
CAN 1(/3)
CAN 2(/4)
Trigger Out
Trigger In
galv
an
ic
al I
s
olat
ion
Power
Housing
Signal
Shield
PE
Ethernet
Signal
Shield
PE
Signal
Shield
PE
Fig. 3-6: Shielding concept