For clarification if you will. The latter mentioned single port function is for a single line remote like would be used with a heavy drag type plow.
The hyd pressure raises the plow in the lift position of the control, and the other position is basically just "drop" It allows the fluid to run out of the implement hyd. cyl. and gravity puts the implement on the ground.
Course in saying this something comes to mind. If you have one line to the control from the tractor hyd system and it is pressurized....has to be to get lift, where does the fluid go that is in the hyd cylinder when you put the conrol in the drop position and drain it?
Would like an answer from someone having used this kind of setup before.....I never have.