When configuring JMRI Decoder Pro, for Bachmann, it provides the following options
  E-Z Command decoder
    - 2 function decoder (36-552)
    - 1 function decoder (36-551) and
    - 4 function decoder (36-550)

Which should we choose for the Bachmann Echo Valley?

I have a Bachmann HO turnout.
There are 3 cables coming out of it.
I connected the middle cable to 0V, from a 12V, 3A power supply
I connected the 12V from the power supply to a common of a electronically operated switch that has a NO and NC connector.
I connected the NO to one side of the cable from the Bachmann turonout and the NC side to the other side of the cable from the Bachmann turnout

A couple of times, when I operated the relay, the turnout switched from one side to the other, but then it stopped working even though I can see that the relay is operating.

Is this connectivity correct?
Is it that 12V is inadequate and a 16V supply is needed?