Currently the firmware allows a station to be associated with only one master (either master 1 or 2 but not both). If you want a station to activate different masters in different programs, here is one possible work-around: remove the definition of masters (i.e. do not us master stations), instead, set the these two stations (let me call them station 1 and 2) as ‘parallel’ (i.e. turn sequential flag off). Then you can schedule station 1 or 2 in a program together with other stations, and set its water time to be at least the total of the other stations. Basically, this is simulating master stations by using parallel stations. A parallel station will turn on together with other stations. So if you schedule station 1 or 2 in a program with other stations, they will turn on together with other stations, which is essentially what a master station does.