# COM Port Settings

To access the dialog box for this setting have no RTU selected and select Options from the top menu. From there select COM Port:

In order to make a local serial communications port connection to an RTU you will need to properly set the COM Port Number for Alarmware™ on your computer. This is the port where you will connect the serial interface cable. If you are not sure what COM Port setting to use connect the serial cable to the RTU and an open communications port. Since it only takes a short time to check each setting available start with COM 1. Next select the Connect COM Port button on the Select RTU dialog box. If Alarmware™ fails to connect, try COM 2, and so on, until connection is successful.

- For information on making a physical serial port connection to the RTU, see Alarmware™ Serial Port Connection .
- For additional information on settings, see Alarmware™ Port Settings.