The TIU gets it's power from Fixed #1 Input or from the aux power jack on the side. I personally wouldn't use the CW-80, but if it's cranked up to full voltage, I believe it will work for a test. The easy way is to connect it to Fixed #1 Input and then you will have the Fixed #1 output connected to the track.
Obviously, to test all the channels will take more work, you'll have to supply input power to each of them in turn.
Here's the MTH DCS Home Page, there is lots of useful information there.