3Com 3012 (3C13612), 3015 (3C13615) Serial Port Cable, Describes crossover network cable pinouts

Serial Port Cable 53

LAN Switch. Straight-through network cables are delivered along with the router.

■Crossover network cable — The sequences of the wires crimped at the RJ-45 connectors of the two ends are different. The cable is used in the connection between the terminal device, such as a PC or a router, and another terminal device. You can create this cable yourself, if necessary.

Table 27 describes straight-through network cable pinouts.

Table 27 Straight-through Network Cable Pinouts

RJ-45	Signal	Category 5	Signal Direction	RJ-45
		twisted pair
1	TX+	White (Orange)	—>	1
2	TX-	Orange	—>	2
3	RX+	White (Green)	<—	3
4	-	Blue	-	4
5	-	White (Blue)	-	5
6	RX-	Green	<—	6
7	-	White (Brown)	-	7
8	-	Brown	-	8

Table 28 describes crossover network cable pinouts.

Table 28 Crossover Network Cable Pinouts

		Category 5
RJ-45	Signal	Twisted Pair	Signal Direction	RJ-45
1	TX+	White (Orange)	—>	3
2	TX-	Orange	—>	6
3	RX+	White (Green)	<—	1
4	-	Blue	-	4
5	-	White (Blue)	-	5
6	RX-	Green	<—	2
7	-	White (Brown)	-	7
8	-	Brown	-	8

You can use Table 28 as a reference while distinguishing or preparing the two kinds of Ethernet cables. While preparing the Ethernet cables, follow the chromatogram given in this table to arrange the wires. Otherwise, communication quality will be affected even though the equipment at two ends is connected.

Serial Port Cable	The synchronous/asynchronous serial port cable is connected to a DB-50
	receptacle. You must select the appropriate cable for the protocol.