Both connections use the same IP so that would make it difficult if not impossible. If they used different IPs they could both be 'online' and by making use of metrics in your routing table it would use one connection.
Oliver's Law:
Experience is something you don't get until just after you need it.
While coming to office today i came across one more idea!
See attacment
Now the thing is i will Disable the port of Backup link and once the primary link goes down i will enable the backup link port. The Real IP is configured on my router WAN interface and static route is defined to gateway / indoor unit IP which is also same for both the connections.
If i wont deploy this than i have to move the router in the deployment area which is 300 m away from the server Room, so when the link will go down one must be going all the way there and plug in the backup link cable.
One machine can do the work of fifty ordinary men. No machine can do the work of one extraordinary man!