RuggedCom RS900GP - Manual (Page 16)

2. Installation
RuggedCom® RuggedSwitch™ 16 RS900GP Installation Guide Rev 101
2.6. RJ45 Ports: Signal Description
The RS900GP has several 10/100BaseTX ports that allow connection to standard CAT-5 UTP
cable with RJ45 male connectors. The RJ45 receptacles are directly connected to the chassis
ground on the unit and can accept shielded CAT-5 cables. If shielded cables are used, care must
be taken to ensure the shielded cables do not form a ground loop via the shield wire and the RJ45
receptacles at either end.
Figure 2.9. RJ45 Port Connector
RJ45 Pin 10/100Base-Tx 10/100/1000Base-Tx
1 RX+ A+
2 RX- A-
3 TX+ B+
4 NC C+
5 NC C-
6 TX- B-
7 NC D+
8 NC D-
Table 2.2. RJ45 Ethernet Pin Assignment
RuggedCom does not recommend the use of CAT-5 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 and
to ensure IEC 61850-3 and IEEE 1613 Class 1 conformance. This means that during
the transient event communications errors or interruptions may occur but recovery is
automatic.
RuggedCom also does not recommended to use 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.