The factory setting for the DT300 is Op#2=x23 with 128 step decoder setting and IR (infrared) tetherless operation enabled.
The factory setting for the DT300R (radio) is Op#2=x03 with 128 speed step decoder operation and tetherless operation for both radio and IR enabled.
Throttle Default Decoder Operation
Each DT300 can be set up to operate new decoders selected by them as any decoder status code you choose. New decoders are defined as decoders that have not been selected in your system. Your DT300 is set to expect to operate mostly decoders that are 128 speed step capable, so when a new decoder is selected the DT300 defaults to that status code. If you operate mostly decoders that are only able to recognize 28 speed steps, you can change this setting. See your decoder specifications and programming manual for more information.
Tetherless Operation Mode
Each DT300 can be set up with radio capability and/or infrared capability enabled, all tetherless operation disabled and power save enabled or disabled.