First posts here, thanks in advance for the help!
I purchased the cooper Rf9540-naw dimmer switch and the rf9500 accessory switch. The master switch (rf9540) is located on a wall that is not easy to access, so I purchased the rf9500 to put right near the entrance of the room.
My question is this: can I use Smartthings to pair the two devices so I can use the accessory switch (rf9500) to control the lights in the room.
Thanks! I did do a search before posting and came across that post. I haven’t bought a ST hub yet (currently using Piper) so some of the details are lost on me. I wanted to make sure they would work before I bought the ST hub, and I couldn’t tell by the post if it was an easy association, or if it involves some coding.
Thanks again!
It looks like the rf9540 and the rf9500 won’t work together. Has anyone out there had luck getting these two to work together?
If you’re still looking for a solution, let me know – I’m putting together a smartapp to do a master-slave and master-master connection between two RF9540’s.
The 9500 is the battery operated switch, right?
In that case, you don’t need to directly associate it the way Cooper describes.
Both devices are Z wave and so both can independently be controlled by smart things. So you can just have the master respond to activity on the 9500 the same way you could have it respond to a handheld minimote or a zigbee switch on another floor or a contact sensor in the garage or whatever.
Essentially instead of the 9500 talking directly to the master, it will talk to the hub and then the hub will send the message to the master. 
There are other master/auxiliary pairs from various brands where the auxiliary is not a network device and can communicate only to the master, not to the hub. In that case the process is different. But as long as the auxiliary is recognized by the Hub as a networked device, Smartthings offers you a much wider set of options.