In this tutorial you will see how to connect to a Fortigate device using console port.
Console cable is an RJ45-DB9 type. In case you don’t have DB9 serial port on your computer you will need for a USB-DB9 mail converter.How to connect Fortigate firewall using serial console cable

You can use different software, I prefer to use Putty to connect. Putty could establish connection to devices that supports serial console connection. Fortigate supports console connector ranges from DB9 to RJ45.
Fortigate console settings are:

Baud Rate (bps): 9600
Data bits: 8
Parity: None
Stop bits: 1
Flow Control: None

You should have these settings configured in Putty.
In Serial line select COM1.

Speed, type in 9600.How to connect Fortigate firewall using serial console cable

Select Serial on the left panelHow to connect Fortigate firewall using serial console cable
Click Open to make connection
Hit Enter on your keyboard.
The login screen should appear
Enter your username and password.