The UPS must support signal on either low battery or power failure.
In the UPS Configuration box in the UPS window, you are provided with three options, including Power failure signal option and the Low battery signal at least 2 minutes before shutdown. You have indicated that your UPS is installed on a serial communications port, and have selected the OK button, but have not selected either of the first two options in the UPS Configuration box. The first of these options (Power signal failure) will alert you only if the main power supply on your computer fails. The second option will alert you when the battery on your UPS device is low two minutes before UPS automatically shuts down your computer.
Select the Power failure signal option if you wish to be alerted by your UPS only in the event of a power failure. Or select the Low battery signal at least 2 minutes before shutdown if you want to be notified before UPS shuts down your computer.