This is one of those things I intend to implement when I have some spare cycles to research, but those spare cycles haven't appeared.
If you want to do the research, start with OID 126.96.36.199.188.8.131.52.491
For exploring Cisco MIBs, use this link:
Well, the issue isn't the polling of the device, or even telling which one is active. The issue is having Orion know that it's actually looking at FWSM2 when it suddenly has the IP of FWSM1.
I've pretty much come to the conclusion that it just can't be done. I changed the names in Orion from FWSM1 and 2 to FWSM(active) and (standby). Hopefully that will alleviate some of the confusion in the future. People will just have to remember that if Orion ever says the standby is down and the active is up then it really means the standby is up and the active is down. I'll lay the fault at Cisco's feet for designing it the way they did. I understand the reasoning behind designing redundancy the way they did, but it makes it as confusing as heck to monitor.