Here are documents pertaining to the Bosch communicating condenser layout.

Newer units will require a communication wire from the ODU to the IDU. If you have a non-communicating IDU then you will need a Bosch communication kit. 

NEW (2026) outdoor heat pumps will have shipped with the outdoor units set for communicating mode. 

To use "4-wire" control (Y,B,W,C) a dip switch (SW5-4) will need to be changed from the default "on" position to "OFF"