Motorola CAJUN P880 - Manual (Page 65)

Cajun P880 Routing Switch Installation Guide 2 - 31
Connecting a
Modem In order to use the serial console port as a PPP console, you must
connect a modem to the switch. When you use the specified serial
cable and connectors, the switch will convert the normal DCE
interface to a DTE interface that is used by modems.
When the switch is configured for PPP mode, it will periodically
send the modem config string from the serial console port. This will
synchronize the baud rates between the modem and the console
port and configure the modem to operate with the switch’s DTE
interface.
The switch does not use any output signals except for TXD. It uses
the DTR (converted to DSR by the specified cable and connectors)
input connected to the modem DCD output, to detect that the
modem is connected. It supports XON/XOFF flow control (or none).
To connect a modem:
1. Attach a DB25M-RJ45 (P/N 38210003)connector to the modem.
2. Attach the DB9M-RJ45 MDCE connector to the switch’s serial
console port on the front panel of the switch.
Figure 17. Typical Connection Between the Switch and a Modem
Configuring the
Serial Console Port
as a PPP Console You can reconfigure the console serial port as a PPP Console to
support a dial-in PPP connection using a modem.
* Note: The lack of an IP address for the PPP serial interface
causes the switch to immediately return to sending the
modem configuration string. Typing TTY will re-access
the CLI login prompt.
Modem
Cajun Switch
DB9M - RJ45
MDCE
DB25 M - RJ45
P/N 38210003
Typical Connection between Cajun
Switch and Modem
Pin 2 - TXD
Pin 3 - RXD
Pin 4 - DTR in
Pin5 - GND Pin 2 - TXD
Pin 3 - RXD
Pin 7 - GND
Pin 8 - DCD out
pin 6 - NC pin 20 - DTR in