EMA’s globally default behavior is to log its messages at a LoggerSeverity level of Success to a file named emaLog_<pid>.log (where pid is the process ID). You can manually change the LoggerSeverity and the logger type by using EmaConfig.xml.
If the does not use EmaConfig file, you have to copy EmaConfig.xml from "<EMA Install Directory>\Cpp-C\Ema\Examples" to your running directory or put it to the same folder as your binary.
Default consumer from the config file is Consumer_1, and it uses Logger_1, so you have to modify section Logger_1 to log message to Stdout instead and set the LoggerServerity to LoggerSeverity::NoLogMsg like below config
Please find more details about the configuration from EMA C++ Configuraiton guide (EMACPP_ConfigGuide.pdf). You can also find EMA default behaviors/config from section 2.3 Default Behaviors.