This is from a project I'm working on. A user can choose between DPDT functionality (so having "SensorI" be a motor that goes forward and reverse) or add another sensor in place of the first sensor having DPDT functionality. The DPDT requires two +VccRelays.

So the relays on the left can be effectively thought of as simply Vcc. This is my current design. It works. (I implemented and tested it.)
Although, I want the user have less switches to screw up. So I figure there's a way to replace the two switches on the right (SW2 & SW4). Do you think this will work:

I tried to make it easier to understand where the switch labels have corresponding letters (where A matches everywhere with A, and B with B). If doing switch B, then the DPDT is enabled.

 

........A................B...................C................D.......


I think that's the truth table. So A⊕B = C = D'

Like that? (I changed "Sensor" to "Motor" so it's more intuitive to understand; it's just like switching the polarity of a DC motor.)

 

All three circuits are the same circuit done in a different way. The first circuit is the current implementation. The user needs to change four switches. I want to reduce that to two switches by replacing the right-side switches (SW2 & SW4 on the first circuit) with logic:

Maybe saying the same thing in a different way will help. The +VccRelay's can either supply power to a "sensor" needing DPDT functionality or instead can be swapped out to power two "sensors." A sensor can be an actuator, such as a motor or pump.
User option 1: Power SensorI with DPDT functionality. (SensorII is offline.)
User option 2: Power SensorI and SensorII, regular sensors only requiring power and ground. (There is no DPDT functionality. E.g., a motor can only go forward, and not reverse.)

 

Why do you don't try to implement it in LADDER Linguage?