You have several options, depending on how you want to use your 622 and your 2nd TV.
Option # 1 - Run the 622 in Single mode
-Under this option, whatever you seen on your primary (HD?) TV you will on see on your second 15 inch analog TV. Under this scenario, you could tune into digital locals from either TV, when when you go to the program guide, you will seen not only your satellite channels, but also your local digitals, no matter which TV you are using. In this mode, you can record one (or even two shows is one of them is a local digital) while watching another. You can also use picture in picture, but both sets would get the same programming.
Option # 2 - Run the 622 in dual mode
-Under this option, Satellite Tuner #1 would primarily serve your main set, and Satellite Tuner #2 would primarily server your second analog set. The local off- the-air digital tuner serves only set number one. The local digitals will not even show up in the program guide when viewing set #2. Under this setup, you could watch a recorded show on either TV while recording another show, but you could not watch one live show will recording another show if both TV's (and tuners) are in use. Although on TV1, you could watch one show live and record a second show if one of those shows is using the off-air digital tuner and the other show is using the satellite tuner. To make this even more complicated, while TV2 has no access to the off-air tuner for watching live TV, TV2 could play back a show that was recorded earlier from the off-air tuner.
Under this setup, TV2 would only have access to live local TV if you subscribe to locals from Dish, or if you use the analog tuner on TV2 to pick-up analog channels off the air (the old fashioned way!)
Also, keep this in mind: The off air tuner in the 622 only receives digital channels. The 622 has no analog tuner. You also probably would need some kind of diplexer if you want to feed TV2 with both the signal from the 622, and an off air antenna (if your planning to use that TV's analog tuner for receiving analog locals.)