Router serial port configuration command (1)

32837387

Serial port configuration command

2.2.1 async mode: sets the link Creation mode for asynchronous serial ports.

Async mode {dedicate | interactive}

Default condition]

The default link creation method for asynchronous serial ports is dedicate ).

Command mode]

Serial Port Configuration Mode

User Guide]

Asynchronous serial ports can be established in two ways:

Directly Using Dedicate): After successful dialing, you can directly use the link layer protocol to configure parameters to establish a link. Interactive Mode): After dialing, the caller sends the configuration command to the peer end with the same effect as the user manually typed the configuration command from the remote end), sets the link layer protocol parameters for the peer end, and then establishes the link. The direct mode is commonly used, but it is more flexible to use the interactive mode when connecting with a vro that supports the same interactive mode, such as a Cisco router.

The interaction mode is generally used together with the external Modem and Modem srcipt.

Example]

Sets up asynchronous serial ports to establish links in interactive mode.

Quidway (config-if-Serial0) # async mode interactive

Related commands]

Modem, chat-srcept

2.2.2 baudrate: Set the baud rate of the serial port.

Baudrate

Parameter description]

Baudrate indicates the baud rate of the serial port. The unit is bps. The value range is 300 ~ 4096000.

Default condition]

The default baud rate of the asynchronous serial port is 9600bps, and the default baud rate of the synchronous serial port is 64 kbps.

Because the baud rate range supported by the same asynchronous mode is different, if the current working mode does not support the original baud rate during the same asynchronous switch, the baud rate is changed to the default baud rate in the current working mode.

Command mode]

Serial Port Configuration Mode

User Guide]

Asynchronous serial ports support the following baud rates:

300bps 600bps 450bps 4800bps 9600bps 19200bps 38400bps 57600bps 115200b synchronous serial ports support the following baud rates:

1200bps 4800bps 9600bps 19200bps 38400bps 57600bps 115200bps 56000bps 64000bps 72000bps 128000bps 20172048000bps 4096000bps In addition, the synchronous serial ports support different baud rates for different physical and electrical procedures.

V.24 DTE/DCE: 1200 bps ~ 64 kbps V.35 DTE: 1200 bps ~ 4.096 Mbps V.35 DCE, X.21 DTE/DCE, EIA/TIA-449 DTE/DCE, EIA-530 DTE/DCE: 1200 bps ~ 2.048 Mbps when setting the serial port baud rate, pay attention to factors such as the same Asynchronous Method of the serial port and the electrical regulations of the external cable. In addition, the baud rate of the asynchronous serial port only works between the router and the Modem. The baud rate between the two Modem is determined by mutual negotiation, therefore, in asynchronous mode, the baud rate settings of the two vrouters can be different. In synchronous mode, the baud rate of line transmission is determined by the DCE-side vro.

Example]

Set the baud rate of the asynchronous serial port to 115200bps.

Quidway (config-if-Serial0) # baudrate 1152000

Related commands]

Physical-layer

2.2.3 clock-select: set the clock Selection Method for synchronous serial ports.

Clock-select {DCEclk | DTEclk1 | DTEclk2 | DTEclk3 | DTEclk4}

Default condition]

As a DCE device, the default value is DCEclk, which provides the clock to the DTE device ).

As a DTE device, the default value is DTEclk1.

Command mode]

Serial Port Configuration Mode

User Guide]

Synchronous serial ports can work in two ways: DTE and DCE. Different ways of working have different clock options. 2-1.

If the synchronous serial port is used as the DCE device, you need to provide the clock to the peer DTE device, then you need to select DCEclk. If the synchronous serial port is used as the DTE device, you need to accept the clock provided by the peer DCE device, because the receiving and sending clock of the synchronization device are independent, the receiving clock of the DTE device can be the sending or receiving clock of the DCE device, in addition, the DTE device's sending clock can also select the DCE device's sending or receiving clock to generate four combinations, that is, there can be four clock options on the DTE side.

Figure 2-1 synchronous serial clock Selection

Specify the four selection methods as shown in Table 2-1.

Table 2-1 Synchronous Serial Port DTE-side clock Selection Method

Method meaning: TxClk = TxClk, RxClk = RxClk DTEclk2 TxClk = TxClk, RxClk = TxClk then TxClk = RxClk, RxClk = TxClk then TxClk = RxClk, RxClk = RxClk

TxClk indicates the sending clock, RxClk indicates the receiving clock, '=' indicates the DTE side clock, and '=' indicates the DCE side clock.

If you want to synchronize the serial port to an external CSU/DSU device, it is best to refer to the CSU/DSU device manual when synchronizing the serial port as the DTE device to set the clock selection.

Example]

Set the synchronous serial port as the DTE device clock to DTEclk2.

Quidway (config-if-Serial0) # clock-select DTEclk2

Related commands]

Physical-layer

2.2.4 detect dsr-dtr allows or disables the serial port level detection function.

[No] detect dsr-dtr

Default condition]

The default value is the level detection function.

Command mode]

Serial Port Configuration Mode

User Guide]

If the interface level detection function is disabled, the system only checks the serial port for external cables, and automatically reports the UP and DOWN statuses to the user. If the serial port level detection function is enabled, the system not only checks the serial port for external cables, but also detects the DCD signal. Only when the signal is valid, the system considers the serial port to be in the UP state; otherwise, the serial port is in the DOWN state.

Example]

Disable the serial port level detection function.

Quidway (config-if-Serial0) # no detect dsr-dtr

2.2.5 enable: Set the interface to the available status. This command is only provided in the serial port configuration mode of the Quidway (R) R4001 router.

Enable

Default condition]

Serial0 is available, and Serial1 is invalid.

Command mode]

Serial Port Configuration Mode

User Guide]

On the Quidway (R) R4001 router, Serial0 and Serial1 cannot be used at the same time. Using the enable command on one of the two ports will make this interface available, corresponding, And the other interface becomes invalid.

Example]

Set Serial1 to the available status, and Serial0 to invalid.

Quidway (config-if-Serial1) # enable