Cabling Specifications

Console Port Pinouts

Console Cable Pinouts

Modem Cable Pinouts

RJ-45 Connector Numbering

10BaseT Pinouts

Cabling Specifications

Following are the pinouts and wiring specifications for the console port (Async 1), console cable, modem adapter for the console port, and 10BaseT port (Ether 0).

The console port (Async 1) is an EIA/TIA-232 interface. Connect a PC serial port or ASCII terminal to this port to configure the Cisco 1020. This port can also be used to connect a second (external) modem. Table A-1 provides the pinout for the Async 1 console port.

Table A-1 : Async 1 Console Port Pinout

Cisco 1020 Async 1 Console Port

RJ-45 Pin Name Definition

1 RTS Request to Send

2 DTR Data Terminal Ready

3 TXD Transmit Data

4 GND Signal Ground

5 GND Signal Ground

6 RXD Receive Data

7 DCD Data Carrier Detect

8 CTS Clear to Send

Cisco 1020 Async 1 Console Port
RJ-45 Pin	Name	Definition
1	RTS	Request to Send
2	DTR	Data Terminal Ready
3	TXD	Transmit Data
4	GND	Signal Ground
5	GND	Signal Ground
6	RXD	Receive Data
7	DCD	Data Carrier Detect
8	CTS	Clear to Send

Console Cable Pinouts

A console cable (see pinout in Table A-2) is supplied with your Cisco 1020. Use this cable to connect a PC (serial port) to the Async 1 (console port) on the Cisco 1020 during configuration. This cable can also be used to connect an ASCII terminal by using a straight-through DB-25 male-male adapter at the terminal end of the cable. The DB-25 male-male adapter is not supplied.

Table A-2 : Console Cable Pinouts

To Cisco 1020
Async 1 Console Port At the PC or Terminal

RJ-45 Name Definition Direction Female DB-25 (DCE) Signal

1 RTS Request to Send -> 5 CTS

2 DTR Data Terminal Ready -> 8¹ DCD

3 TXD Transmit Data -> 3 RXD

4 GND Signal Ground NC

5 GND Signal Ground 7 GND

6 RXD Receive Data <- 2 TXD

7 DCD Data Carrier Detect <- 20 DTR

8 CTS Clear to Send <- 4 RTS

NC Data Set Ready 6¹ DSR

¹ Pins 8 and 6 in the DB-25 are connected internally.

To Cisco 1020 Async 1 Console Port		At the PC or Terminal
RJ-45	Name	Definition	Direction	Female DB-25 (DCE)	Signal
1	RTS	Request to Send	->	5	CTS
2	DTR	Data Terminal Ready	->	8¹	DCD
3	TXD	Transmit Data	->	3	RXD
4	GND	Signal Ground		NC
5	GND	Signal Ground		7	GND
6	RXD	Receive Data	<-	2	TXD
7	DCD	Data Carrier Detect	<-	20	DTR
8	CTS	Clear to Send	<-	4	RTS
NC		Data Set Ready		6¹	DSR

Modem Cable Pinouts

Use a modem cable (see pinout in Table A-3) to connect an external modem to the Async 1 (console port) on the Cisco 1020.

Table A-3 : Modem Cable Pinouts

To Cisco 1020
Async 1 Console Port At the Modem

RJ-45 Name Definition Direction Male DB-25 (DTE) Signal

1 RTS Request to Send -> 4 CTS

2 DTR Data Terminal Ready -> 20 DCD

3 TXD Transmit Data -> 2 RXD

4 GND Signal Ground NC

5 GND Signal Ground 7 GND

6 RXD Receive Data <- 3 TXD

7 DCD Data Carrier Detect <- 8 DTR

8 CTS Clear to Send <- 5 RTS

To Cisco 1020 Async 1 Console Port		At the Modem
RJ-45	Name	Definition	Direction	Male DB-25 (DTE)	Signal
1	RTS	Request to Send	->	4	CTS
2	DTR	Data Terminal Ready	->	20	DCD
3	TXD	Transmit Data	->	2	RXD
4	GND	Signal Ground		NC
5	GND	Signal Ground		7	GND
6	RXD	Receive Data	<-	3	TXD
7	DCD	Data Carrier Detect	<-	8	DTR
8	CTS	Clear to Send	<-	5	RTS

Note The cabling kit, available from Cisco, contains a rolled RJ-45 cable plus an MMOD cable (RJ-45 to DB-25 adapter).

RJ-45 Connector Numbering

The 10BaseT Ethernet port (Ether 0) and console port (Async 1) are both female RJ-45 connectors. Figure A-1 shows pin numbering for female RJ-45 connectors.

Figure A-1 : RJ-45 Female Connector

10BaseT Pinouts

The 10BaseT cabling from the network to the Cisco 1020 must be straight-through, twisted-pair. Each of the four pairs of wires that make up the twisted-pair cable must be individually twisted. Figure A-2 shows straight-through cables.

Figure A-2 : Twisted-Pair Wiring Configuration---Straight-Through Cables

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