Parameters of energy function for TSP
There is no way to choose the parameters A, B, C, D properly; 
as it is the case for most heuristics, the parameters are chosen ''by experience''. 
Worse, there is no guarantee that the solution (the array of the outputs) 
of this heuristic is indeed a feasible TSP tour! 

In this context, perhaps interesting to read: Wilson and Pawley, 
On the stability of the Travelling Salesman Problem 
algorithm of Hopfield and Tank, 
Biological Cybernetics 58 (1988) 63-70.  

To your first comment: I don't think that this TSP energy function is useful for practical purposes. 
If you want to solve TSP in practice, maybe here 
is the right starting point.