For Serial Studio the mcu should start a frame with /* and end with */ and the data values separated by ','
Here is an example
uint8_t usbBuf[64];
uint16_t usbBufLen;
usbBufLen = (uint16_t) snprintf(usbBuf, 64, "/*%.2f, %.2f, %.2f*/\r", rawPressure_Pa, procPressure_Pa, procRelAltitude_m);
CDC_Transmit_FS(usbBuf,usbBufLen);
It will look like
/* 40125.34, 40125.21, 0.15 */