Chapter 2: Hardware Installation and Network Configuration
7
Table 2.5 lists the pin assignments for the RS-485 CAT 5 adaptor.
Ethernet connector
Table 2.6 lists the pin assignments for the RJ-45 shielded Ethernet connector.
Table 2.5: RS-485 CAT 5 Adaptor Pin Assignments
Pin Number - DB-9
RS-422
Description
Pin Number - RJ-45
1
RxD (+)
Receive Data (pos)
4
2
RxD (-)
Receive Data (neg)
5
3
TxD (+)
Transmit Data (pos)
4
4
TxD (-)
Transmit Data (neg)
5
5
GND
Ground
N/C
6
DSR (RS-232)
Data Set Ready
N/C
7
RTS (RS-232) *
Request to Send
N/C
8
CTS (RS-232) *
Clear to Send
N/C
9
N/C
N/A
N/C
RxD(+) and TxD(+) are both connected to pin 4 of the RJ-45 connector.
RxD(-) and TxD(-) are both connected to pin 5 of the RJ-45 connector.
* RTS is tied to CTS inside the adaptor to indicate an RS-485 connection.
Table 2.6: Ethernet Connector Pin Assignments
Pin
Signal
1
Transmit Data +
2
Transmit Data -
3
Receive Data +
4
*
5
*
6
Receive Data -
7
*
8
*
* These pins are usually connected in a standard Ethernet CAT 5 cable. There is special termination for these
signals in the interface to eliminate any problems if they are connected.