National Instruments PCI-8430 - Page 102

Two-WireMode:DTRControlled
Thismodeissimilartothetwo-wire,DTR-with-echomode.Althoughthis
modeusesthesamemethodastheDTR-with-echomodetocontrolthe
transmitter,thehardwareautomaticallydisablesthereceiverwhenever
thetransmitterisenabled.Thus,youdonotreceivethepacketssent
fromyourtransmitter.