Inside one indicator you calculate/set a global variable to the value you want... And then inside the other module you check the global variable and use the returned value for you needs.
Here is an example I use in an indicator to tell an ea when it OK to trade..
//use global flags to signal time to trade to ea.
GlobalOkToTradeSymbolFlag="GlobalTradeFlag_"+MagicNumber;
if (GlobalVariableCheck(GlobalOkToTradeSymbolFlag)) GlobalVariableDel(GlobalOkToTradeSymbolFlag);