CCS/AWR1843BOOST: Continous mode Configuration

Tool/software: Code Composer Studio

HI,

Now,I want to set Continous mode Configuration,my code  is belllow:

rlContModeCfg_t contMode;
rlContModeEn_t contEnableCfg;
contMode.vcoSelect = 0; /* 76-78G VCO */
contMode.digOutSampleRate = 4000;
contMode.startFreqConst = freqInMHz / 53.644f * 1e6;
contMode.rxGain = 24;
contMode.txOutPowerBackoffCode = 0;
rlSetContModeConfig(RL_DEVICE_MAP_INTERNAL_BSS, &contMode);

contEnableCfg.contModeEn = 1;
rlEnableContMode(RL_DEVICE_MAP_INTERNAL_BSS, &contEnableCfg);

BUT,i can not choose TX channel,there are there TXs ,four RXs in AWR1843,If i do like above,Will there be 3 antennas to be in work???I just want only one TX to be in continuous mode!