@RWL posted:..If so, what if I flipped the DPDT to the Center Off position, then opened the switch to which ever track the DCS located on, then flipped the DPDT to the DCS-RC side again.
That should send the watchdog signal to that engine.
Would that be correct?
Correct! Honestly that is quite an astute assessment of the situation! 
So for your sidings (powered by Z-1000), let's say there are 8 SPST on-off toggle switches as shown on right.
When you want to turn on a siding with a DCS engine on it,
1. set the DPDT to the center-off position. This removes power from the DCSRC (and to any sidings that happened to be ON).
2. set the SPST switches to enable one or more sidings - as you mentioned earlier you might have more than 1 siding ON at a time.
3. flip the DPDT to the Z-1000 brick position. This simultaneously powers up the DCSRC and the selected siding(s). The DCSRC watchdog barks and any DCS engines on a newly powered siding will startup silently and ready for action from a DCSRC remote command.
So. If willing to perform steps 1 and 3 (which only takes a second or two), you do NOT need a DCSRC modified with the Perpetual Barking Watchdog board.
