6-11
z
If the check fails, the receiving program sends a negative acknowledgement character and the
sending program retransmits the packet.
Modifying Serial Port Parameters
In actual applications, you may need to make the serial port baud rate higher to reduce upgrading time
or make it lower to guarantee transmission reliability. This section introduces how to adjust the serial
port baud rate.
Step1
Enter the main menu and select
2
to enter the serial submenu, and then select
5
to modify the baud rate.
The system displays the following:
============================<BAUDRATE SET>============================
|Note:'*'indicates the current baudrate |
| Change The HyperTerminal's Baudrate Accordingly |
|-----------------------<Baudrate Available>-------------------------|
|<1> 9600(Default) * |
|<2> 19200 |
|<3> 38400 |
|<4> 57600 |
|<5> 115200 |
|<0> Exit |
======================================================================
Enter your Choice(0-5):
Step2
Select a proper baud rate. For example, select
5
for a baud rate of 115200 bps and the system displays:
Baudrate has been changed to 115200 bps.
Please change the terminal's baudrate to 115200 bps, press ENTER when ready.
At this time, the baud rate of the serial port of the firewall is 115200 bps, while that of the terminal is still
9600 bps. The firewall and the terminal cannot communicate with each other with different baud rates.
Therefore, you need to make the baud rate on the terminal consistent with that on the firewall.
Step3
Perform the following operations on the terminal:
Figure 6-2
Disconnect the terminal
Step4
Select
File
>
Properties
, and then click
Configure…
to change the bits per second to 115200.
