How can I add a setpoint manager to DX:CoolingCoil outlet node in a ruby script?

edit

If you have the Coil:Cooling:DX assigned to a variable coil, and you're sure that coil is on the airloop (i.e. it is listed as a supply component on the loop) you should be able to call

node = coil.outletModelObject.get.to_Node.get

to get the outlet node assigned to node. If you're not sure the coil is assigned to a loop, you might need to add a check that coil.outletModelObject.is_initialized before 'getting' it.