Linkstation Mini monitoring Network UPS

[atiras]

I have a small network with 3 assorted NAS systems (an LS-WSXL Linkstation Mini with firmware 1.64, an LS-WSGL/R1 Linkstation Mini with firmware 1.06 and a NAS from another manufacturer) and a desktop PC. All these devices are connected to an APC UPS, which has a USB connection to the third-party NAS. The third-party NAS is set to act as a network UPS server, and the newest Linkstation Mini is set to synchronize with UPS connected to other LinkStation on the network using the IP address of the third-party NAS. The PC also monitors the third-party NAS. (I know it isn't possible to set the older Linkstation Mini up to monitor for a network UPS).

In the event of a power failure, the third-party NAS and the PC shutdown gracefully, but the LS-WSXL doesn't react. Is the Linkstation monitoring for a proprietary protocol to detect power failure, or should this set up work?

And if it won't work, what options do I have for issuing a graceful shutdown command to the Linkstations from the PC?