- useful when used in a batch process to trap the exit signal,
  e.g. stop the run when the velocity magnitude exceeds a given
  threshold:

    runTimeControl
    {
        type            runTimeControl;
        libs            ("libutilityFunctionObjects.so");
        nWriteStep      1;

        // Optional end 'action'
        satisfiedAction abort; // end; // setTrigger

        conditions
        {
            maxU
            {
                type            minMax;
                functionObject  MinMax;
                fields          ("max(mag(U))");
                value           1e6;
                mode            maximum;
            }
        }
    }