Red Hat Knowledgebase

If you are having difficulty using your serial ports, troubleshooting can be performed with the setserial utility. Issuing the command setserial -a <serial port name> should dump all relevant information out to the console regarding that serial port. This information can be used to configure commands like cu. The cu command is used to call up another system and act as a dial in terminal.

# setserial -a /dev/ttyS0 /dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4 Baud_base: 115200, close_delay: 500, divisor: 0 closing_wait: 30000 Flags: spd_normal skip_test auto_irq

For more information, see the man pages for setserial and cu. From the command line, type man setserial or man cu to access the documentation.