Connecting Category-5 Cables - 3Com S7906E Getting Started Manual

Connection procedure
The connection procedure of the RS-232 port and that of the RS-485 port are shown respectively as
follows (taking the S7902E using the PSE2500-A as an example):
If the RS-232 port is used, use an 8-core shielded cable. One end of the cable is a crimped RJ-45
connector, which is connected to the RS-232 COM port on the rear panel of the S7902E; the other end
is attached with a DB-9 female connector and can be connected to the RS-232 port of PSE2500-A. The
COM cable is similar to the console cable. For details, see
If the RS-485 port is used, use a straight through cable to connect the COM port with the RS-485 port on
the PSE2500-A.
The PoE monitoring port on the PSR1400-D is an RS-485 port. You can select a proper connection
method for the RS-485 port according to the type of the PoE monitoring port on the external power
module.
When the S7900E series adopt only the –48 V DC power, but no external PoE power supply, it is
unnecessary to connect the COM port.

Connecting Category-5 Cables

Introduction to the RJ-45 connector
10Base-T/100Base-TX and 1000Base-T ports of the S7900E series use RJ-45 connectors, support
MDI/MDIX auto-sensing, and adopt category-5 cables. The following figure illustrates the appearance
and pinouts of RJ-45 connector.
Figure 3-15 RJ-45 connector
Table 3-2 RJ-45 MDI interface pinouts
Pin
Signal
1 Tx+
2 Tx-
3 Rx+
10Base-T/100Base-TX
Function
Send data
Send data
Receive data
Figure 3-14.
1000Base-T
Signal
BIDA+ Bi-directional data cable A+
BIDA- Bi-directional data cable A-
BIDB+ Bi-directional data cable B+
3-13
Function