How to determine serial port

[Jeff Boyce]

Greetings -

I am novice linux administrator for a small office file server and am 
installing software for managing my UPS system.  The instructions state for 
me to set ownership data and permissions on the serial port that is 
connected to the UPS hardware.  It uses an example of:

chmod 0600 /dev/ttyS1
chown user:group /dev/ttyS1

but also states that serial ports vary greatly and therefore mine may be 
called something else.  How do I determine what tty my serial port is?  I 
have a Dell PE 2600 with two serial ports in the back with my UPS plugged 
into the #1 port.  My OS is RHEL3.  Thanks.

Jeff Boyce
www.meridianenv.com