Versuche es mal mit dieser Variable: $RGSPD_PREXE
Beschreibung:(leider nur englisch)
Name: Register Speed Pre Execution
Description: This variable controls the interpreter pre-execution when a register value is used for the
speed parameter. The default value is FALSE which means to stop the pre-execution. If it is set to
TRUE then pre-planning is not stopped. In this case, if the user changes the register used for the speed
immediately before executing the motion the speed which is used will be the previous value of the
register. If the register is not typically changed right before issuing the motion then it may be safe
to allow the pre-execution to occur.