I have been tasked to do this except the people tasking me thought that it was just a Hi/Low arrangement where this valve wired into a Raypack boiler has a series of relay/resistors to modulate it between low and high fire.

Several years ago i used a voltage to resistance transducer to control something similar on a roof top unit but i forget the details and most of my office is already on vacation so i have no backup to check old files and such.

Has anyone ever controlled a gas valve like this and do you recall what you used or could you point me at something? Blind internet searching is not giving up the booty