[CentOS] OT: really dumb question about APC UPS

We have about 4 servers connected to an APC UPS. The UPS only has one
UPS connection. So my question is, in a power outage how do i get all
my servers to safely shutdown? Do i run a USB hub? Do i write a script
on the one machine connected to turn off all the other machines? I'm
confused.

Jamie