I tried to use a EMS program to control the condenser supply outlet node. There should be two essential operation conditions: HX ON (1 = active) and HX off (0 = not active). The concept is, that for the request if the HX is active or not active the "Fluid Heat Exchanger Operation Status" should be used. The operation status shows also interim values between 0 and 1. Based on the operation condition I would set the setpoint. I tested the following program and found out that when the operation status reached "HXStatus" = 0 it is not possible to get back (when a change could be happens to HX=ON, a change of the OutdoorTemp from high to low). It seems to be that the command "SET CondLoopTempSched = 20" will be always executed. With the command "SET CondLoopTempSched = OutdoorTemp" in the first programm line I wanted to stop this case. But I think the problem is, that the "Fluid Heat Exchanger Operation Status" couldn't have some changes within the EMS program. So currently I have no concept to save this problem.