Operation mode of axes
CNC-axes can be divided into axis with drive-internal or CNC-internal position controller. With SERCOS drives both operation modes are possible. The operation mode of an axis is set in the axis parameter P-AXIS-00320 (operation_mode):
 | Presently the axis parameter P-AXIS-00320 (operation_mode) is used only for SERCOS axes. |
Variable name | Type | Permissible range | Axis type | Dimension |
operation_mode | ISG_CHAR | See strings at following table | T, R | ---- |
String | Significance |
DRIVE_DEFAULT | Default setting for all drive types. The used operation mode ( position control in the drive, position control in the numerical control, velocity control, etc. ) is determined automatically. It depends e.g. on the drive type P-AXIS-00020 and on the configured telegram. |
DRIVE_POSITION_CONTROL | In this operation mode the position or velocity control is performed in the drive. |
CNC_POSITION_CONTROL | The position control is performed in the CNC. |
If no operation mode is defined for an axis, the control uses the default setting. The following table shows an overview of the possible operation modes in dependency of the drive type. The default setting for each drive type is shown in bold characters.
Drive type | Position control in drive | Position control in CNC |
|---|---|---|
Conventional drive |
| X |
SERCOS | X | X |
ProfiDrive MC | (X) | X |
Drive simulation |
| X |
Lightbus |
| X |
Terminal (±10V) |
| X |
Realtime-Ethernet |
| X |
CANopen | X | X |
Virtual axis |
| X |
In the operation mode „position control in drive“ the calculation of the position lag value of ProfiDrives is performed in the CNC.
The selection of the operation mode for axes with CANopen drives is done in the CNC depending on the configured bus telegram. The position control is performed in the drive if command positions are transmitted. If however, only a velocity command is transmitted to the drive, the position control is performed in the CNC.