So one important thing is, when having a technical discussion about these electronic control systems you have to know and specify the train in question. In other words we have no details for what product numbers are involved. As such, we have no idea of what versions of electronics are involved.
Why that matters??? One of the ways without even looking or knowing what a DCS capable engine is is by how it runs specific to direction control.
PS2 engines. If you are moving at a speed in DCS, and then command a direction control, the first thing it does is set the speed control to 0 MPH, however the momentum of the train settings in engine settings stored in that train determines how long it takes to get down to actual zero dead stopped. Then the relay kicks in and it changes direction mode. If you make the mistake of changing the speed BEFORE it actually gets to 0MPH after a direction change, it will not change direction. Again, let me repeat this, if you have the train moving and hit direction, rather than slamming to a stop or changing direction instantly, it slows down to 0MPH as if you had double tapped the brake button or set speed to 0MPH. Then, only after completely stopped, the engine then changes the relay state and now is engaged and ready to go into the other direction. If you roll the speed dial before it has come to a complete stop and stopped for 1 second, then even though the lights are indicating reverse, the motor control will not change direction. This is normal and how the system was designed.
PS3 engines. PS3 operates slightly differently. If you are moving and hit direction, it will again slow down, go all the way to zero and then change direction even if you change the speed after the direction button was hit but before the train actually comes to a stop. Again, PS3 operates very differently in this regard.
If you mix the 2 engines (PS2 and PS3) into a consist (Lashup, MU), and then break the rule of never changing the speed dial after hitting direction button before the train comes to a complete 0MPH stop, then you can invoke the difference and the PS3 will change directions and the PS2 will continue to fight and try to go the previous direction.
