ReadyNAS communication w/ UPS over network

Thanks so much, mdgm. The UPS is now connected directly to the ReadyNAS. I'll call this one the "master." I have a second ReadyNAS that is in a different IP range, which I'll call the "slave". On the master, I configured the 2nd NIC of the ReadyNAS to be in the same IP range as the slave. This 2nd NIC is connected to the same switch as the ReadyNAS slave. I verified that I can get to the master's admin page using the alternate IP address. But, I can't figure out how to get the slave to add the UPS that is physically connected to the master. It won't communicate with the master when I try to add the UPS. I used the basic instructions here - http://kb.netgear.com/app/answers/detail/a_id/23121

Name of the UPS: UPS
Type: Remote UPS
Address: IP of the 2nd NIC of the master ReadyNAS
user: monuser
pass: pass

I know this is unusual and a networking guru could probably get this to work through the switches, etc. But, I'm trying to make due with the limited skillset I have. I really appreciate any help you might offer.