The way I do it is to start with loco1 on controller1 running round loop1........then start controller2 with loco2 on loop2........you can then go back and press cont1, press the loco button and enter your next loco address so you'll have control of loco3 to go shunting etc but you have temporarily lost control of loco1 which will continue round it's loop at the speed you left it........if you have a third loop for loco3 you can then press controller2 then loco button, enter another address and have control of loco4 but you have lost control of loco2......so you have to remember the 4 loco addresses and on which tracks they are running.......you can easily stop one loco then go back to the other one to gain control.(after you have stopped the running loco first).......clear as mud 😮..........HB