RabbitCore eDisplay OP7200, Руководство пользователя

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User’s Manual 37
3.5.4 Ethernet Port
Figure 17 shows the pinout for the Ethernet port (J2 on the OP7200’s RabbitCore module).
Note that there are two standards for numbering the pins on this connector—the convention
used here, and numbering in reverse to that shown. Regardless of the numbering conven-
tion followed, the pin positions relative to the spring tab position (located at the bottom of
the RJ-45 jack in Figure 17) are always absolute, and the RJ-45 connector will work prop-
erly with off-the-shelf Ethernet cables.
Figure 17. RJ-45 Ethernet Port Pinout
RJ-45 pinouts are sometimes numbered opposite to the way shown in Figure 17.
Two LEDs are placed next to the RJ-45 Ethernet jack, one to indicate a live Ethernet link
(
LNK ) and one to indicate Ethernet activity ( ACT ).
The transformer/connector assembly ground is connected to the OP7200’s RabbitCore
module printed circuit board digital ground via a 0
Ω
resistor “jumper,” R29, as shown in
Figure 18.
Figure 18. Isolation Resistor R29
The factory default is for the 0
Ω
resistor “jumper” at R29 to be installed. In high-noise
environments, remove R29 and ground the transformer/connector assembly directly
through the chassis ground by using the EGND terminal on the RabbitCore module. This
will be especially helpful to minimize ESD and/or EMI problems.
ETHERNET
RJ-45 Plug
1. E_Tx+
2. E_Tx–
3. E_Rx+
6. E_Rx–
1
8
RJ-45 Jack
RJ-45 Ethernet Plug
R29
Chassis
Ground
Board
Ground