Image may be NSFW.
Clik here to view.
There's a lot of confusion about that single, red-labeled port on a DIRECTV splitter. A customer recently asked if that's where your Genie DVR goes, and that sort of makes sense.
The red port is the power-passing port. DIRECTV equipment needs power to function and rather than plugging your dish or multiswitch into a wall outlet, that power is carried through the coaxial cable. This makes it a lot easier to place the dish or multiswitch since there doesn't need to be an outlet nearby.
Somewhere in your DIRECTV SWM system you have a grey or black box that looks something like this:
Image may be NSFW.
Clik here to view.
This is the power inserter. It's only job in life is to put power onto the coaxial cable. However, since that power could fry your receivers, the whole system is built with safeguards. Most of the ports on the splitter have built-in DC blocks that stop voltage from coming across the cable into your receiver. That's a good thing. However, one of those ports needs to pass the power through... or else it can't get to the dish!
That port that passes power has a red center to let you know that it has extra capabilities. The power inserter needs to be plugged into a red port, but if you already have the power inserter plugged into another splitter, you can use the red port for anything you need. (You don't need a second power inserter just because you need another splitter.)
So now maybe you're asking, if I plug a receiver into that red port, why doesn't it fry since power could flow through it? The answer is simple. DIRECTV splitters are designed so the power flows "up" through the splitter toward the dish, not "down" to other splitters. So you're completely safe.
At the end, the answer is, plug the DVR into whichever port you want, as long as you have room for the power inserter.
Clik here to view.

There's a lot of confusion about that single, red-labeled port on a DIRECTV splitter. A customer recently asked if that's where your Genie DVR goes, and that sort of makes sense.
The red port is the power-passing port. DIRECTV equipment needs power to function and rather than plugging your dish or multiswitch into a wall outlet, that power is carried through the coaxial cable. This makes it a lot easier to place the dish or multiswitch since there doesn't need to be an outlet nearby.
Somewhere in your DIRECTV SWM system you have a grey or black box that looks something like this:
Image may be NSFW.
Clik here to view.

This is the power inserter. It's only job in life is to put power onto the coaxial cable. However, since that power could fry your receivers, the whole system is built with safeguards. Most of the ports on the splitter have built-in DC blocks that stop voltage from coming across the cable into your receiver. That's a good thing. However, one of those ports needs to pass the power through... or else it can't get to the dish!
That port that passes power has a red center to let you know that it has extra capabilities. The power inserter needs to be plugged into a red port, but if you already have the power inserter plugged into another splitter, you can use the red port for anything you need. (You don't need a second power inserter just because you need another splitter.)
So now maybe you're asking, if I plug a receiver into that red port, why doesn't it fry since power could flow through it? The answer is simple. DIRECTV splitters are designed so the power flows "up" through the splitter toward the dish, not "down" to other splitters. So you're completely safe.
At the end, the answer is, plug the DVR into whichever port you want, as long as you have room for the power inserter.