Can the DS52 be powered directly from a 13.8 v DC external power supply instead of the rails? No. Screw Terminals 4 & 5 are used to not only supply power to the DS52 from the track but also are the path that is used to both program the DS52 and to operate the DS52 via a throttle or computer program.
There are two jumpers on the DS52 stationary decoder board. To properly use your DS52 you must be sure these jumpers are in the correct position. The configuration jumper sets whether your DS52 operates slow motion or solenoid type turnout machines. When the jumper is open it will run solenoid turnout machines. When it is closed it will operate slow motion turnout machines. The programming jumper determines whether the DS52 is in programming mode or not. To program the addresses for the DS52 the program jumper must be closed. For normal operation, it must be open.
Q: I am building a new DCC layout that will include a logging spur that is simply a single long piece of track with no loop. I want to have a train go back and forth on this track which automatically reverses when it gets to each end. While the AR1 was designed for reversing loops, can it be wired to simply reverse a train on a straight piece of track? A: Not in the way that you intend. One of the interesting problems with DCC is that we often still think in terms of DC, where the track polarity ...