Rabbit Smartcat, Руководство пользователя

Страница: 32 / 135

26 Smartcat (BL2100)
3.3.3 Ethernet Port
Figure 15 shows the pinout for the Ethernet port (J2 on the BL2100 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 convention
followed, the pin positions relative to the spring tab position (located at the bottom of the
RJ-45 jack in Figure 15) are always absolute, and the RJ-45 connector will work properly
with off-the-shelf Ethernet cables.
Figure 15. RJ-45 Ethernet Port Pinout
RJ-45 pinouts are sometimes numbered opposite to the way shown in Figure 15.
Two LEDs are placed next to the RJ-45 Ethernet jack, one to indicate an Ethernet link
(
LNK
) and one to indicate Ethernet activity (
ACT
).
The transformer/connector assembly ground is connected to the BL2100 module printed
circuit board digital ground via a 0

resistor “jumper,” R29, as shown in Figure 16.
Figure 16. Isolation Resistor R29
The factory default is for the 0

resistor “jumper” at R29 to be installed. In high-noise
environments, remove R29 and ground the transformer/connector assembly directly
through the chassis ground. 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