Technical data

Programming
CPU 317T: Technology Functions
A5E00251798-03
5-15
5.8 Behavior of Virtual Axes
Virtual axes have a reference input variable, but do not have a position control
system, nor a drive or an encoder interface. The process value of the virtual axis is
always set equal to the setpoint value. The absence of the position control system,
the drive and encoder interface lead to some particular aspects at job processing
which are described below:
<Particular behavior of the variables Statusword.DriveEnable
If the enable of a virtual axis is removed at the Enable input parameter of
MC_Power, the status of the Statusword.DriveEnabled variable of the
corresponding technology DB remains TRUE.
The Statusword.DriveEnable variable is always TRUE at a virtual axis.
Parameter changes during the runtime of the technology CPU
• Restart
Because virtual axes do not have a position control system, drive or encoder
interface, a restart is often not required when a parameter is modified, even if
the contrary is stated in the help texts for the dialog boxes or in the list of
technology parameters.
Whether a restart is required, is indicated in the variable
Statusword.RequestRestart of the corresponding technology DB.
• Parameter modifications
All the parameters of the axes are listed in the list of technology parameters as
well as in the dialog boxes of the DB Param.
Take into account that not all the parameters can be read or modified at virtual
axes.