I have an A-off-B toggle switch that toggles power feed to two rotary switches. One rotary handles the turntable spoke tracks and the second handles the adjacent freight yard. I patched the DCS-RC into this feed and gave it a try. Works perfectly. Any selected PS-2 or PS-3 engine stays dark and silent until you select it and hit startup. This is a nice simple scheme as mentioned earlier in this thread, for sending the watchdog to a command engine, each time a new TT or yard track is selected. Well after the main TIU watchdog has come and gone.
I also ran a brief test to get an idea how long the TIU watchdog signal lasts. Looks like its less than 15 seconds. This is an I3a rev TIU.
Rod