How to do that depends on what API you are using.
In the interactive you do
set log *
In C you use
CPXsetintparam(env, CPX_PARAM_SCRIND, CPX_OFF)
In the object oriented APIs you use the setOut() and setWarning() methods of class IloCplex to install an output destination that just swallows all output..
See the reference documentation here.
#CPLEXOptimizers#DecisionOptimization