Select Program➔ Set Tool Frame Instruction to use a specific tool frame (TCP). This will update the given tool frame on the program for the following movement instructions and will change the Active tool frame of the robot in RoboDK for simulation purposes. That means that movement instructions to specific target (Cartesian targets) will be made with respect to the last tool frame set.
The reference frame is a variable also known as ToolData (ABB robots), UTOOL (Fanuc robots), TOOL (for Motoman robots) or $TOOL (for KUKA robots).