[CentOS] how to rescan serial ports without reboot

Hi all,

I hope this is possible. I have a server, with a network switch
attached to the serial port, and I want to rescan the serial port
(/dev/tty) to see if it picks it up? I'd prefer not to reboot the
server if at all possible.

dmesg reports ttyS0 as the active port:

[root at zabackup01 ~]# dmesg |grep tty
Bootdata ok (command line is ro root=/dev/System/root rhgb quiet xencons=tty6)
Kernel command line: ro root=/dev/System/root rhgb quiet xencons=tty6
WARNING: Failed to register Xen virtual console driver as 'tty1'
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
ttyS0: 1 input overrun(s)
ttyS0: 1 input overrun(s)


running screen /dev/ttyS0 doesn't show up anything, and I should at
least get the switch's login prompt.

-- 

Kind Regards
Rudi Ahlers