Since fixed 1 doesn't seem to be working try fixed 2....This is how you might hook it up....hook up one side of the Z-4000 to fixed 1 IN..... This will turn on the tiu so that it can"turn on" .... function or do it's thing
Hook up the other side of the Z-4000 to fixed 2 in... Fixed 2 out goes to the track.
Each tiu channel has a signal generator, It appears fixed 1 is not working so give fixed 2 a try...
A small test track works the best with only one engine receiving power, the other engines should be removed from the track or parked on dead tracks. good luck.