So you are wanting to control the 2800 and 510 with the remote that the 510 came with? You will be able to operate the 2800 with IR but not UHF because the 2800 does not have the capability built in. If you get the UHF upgrade kit where you get the pyramid then you will get a UHF remote with it that will operate it. If the 510 has a DishPro UHF remote then it will not work on the pyramid. The pyramid changes the IR
So you are wanting to control the 2800 and 510 with the remote that the 510 came with? You will be able to operate the 2800 with IR but not UHF because the 2800 does not have the capability built in. If you get the UHF upgrade kit where you get the pyramid then you will get a UHF remote with it that will operate it. If the 510 has a DishPro UHF remote then it will not work on the pyramid. The pyramid changes the UHF signal into IR for the receiver to understand if it is not a DishPro UHF remote. It will work with the UHF remote that comes with it. If the 510 remote is not DishPro then it will work with the 2800 if you get the pyramid kit but in either case the IR from the 510 remote will work with the 2800 if you are in the same room.