Installation
2.5 RJ45 Ports – Signal Description
10/100Base-TX ports allow connection to standard Category 5 (CAT-5) unshielded
twisted-pair (UTP) cable with RJ45 male connectors. The RJ45 receptacles are
directly connected to the chassis ground on the unit and can accept CAT-5 shielded
twisted-pair (STP) cables. If shielded cables are used, care must be taken to ensure
that a ground loop is not formed via the shield wire and the RJ45 receptacles at
either end. Figure 9 shows the RJ45 port pin-out.
Figure 9: RJ45 Ethernet port pin-out
Pin
Signal
1 +Rx
2 -Rx
3 +Tx
4 Terminated
5 Terminated
6 -Tx
7 Terminated
8 Terminated
Case
Shield (Chassis Ground)
Table 6: RJ45 Ethernet port pin-out
NOTE:
The unused pins, 4, 5, 7, and 8 are terminated to Chassis Ground via a network that
improves EMI and ESD performance.
RuggedCom does not recommend the use of copper cabling of any length for critical
real-time substation automation applications. However, transient suppression
circuitry is present on all copper ports to protect against damage from electrical
transients. This means that during a transient event, communications errors or
interruptions may occur but recovery is automatic.
RuggedCom also does not recommend using these ports to interface to field devices
across distances which could produce high levels of ground potential rise, (i.e.
greater than 2500V) during line to ground fault conditions.
RuggedSwitch™
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