I don't have a link to how Digital TVGOS works. It works very much like analog TVGOS but is delivered as a separate PID in the ATSC signal, instead of in the VBI as was done with analog. Much of the information about how TVGOS works was derived from the diagnostic screens that are in most TVGOS devices. Since Echostar didn't provide any TVGOS diagnostic screens, it is virtually impossible to figure out how any of this works by looking at the DTVPal. Most of what I have learned about TVGOS came from people who had already figured it out before I even became interested in learning about it. At that point analog TVGOS had been around for several years. The log that was posted the other day, made no sense to DTVPal owners, which is what J-D-H pretty much figured out. So its "on topic" value is questionable. If the log was made so that it only showed the timestamps and the offset, then it might be useful to someone here. Although it would be much more useful if it was actual data from WUSA.
The term MDI was coined by another AVS member in the Sony thread (sort of as a joke but the term stuck). It is useless information for people in this thread (thus it is way off topic). It is a technique that I came up with to help the Sony DHG "build a grid" (something that DTVPal owners don't have to worry about). MDI stands for "mabuttra data interrupter". It is nothing but an RF switch to allow turning on and off the antenna signal going into the DHG. The reason for doing this can be found (with some digging) in the Sony thread, but has nothing to do with any TVGOS device except the Sony DHG.
Now we return back to the regular DTVPal thread.