# ID 20467

Slave axis is not allowed to be a main axis.
Description | When selecting synchronous operation, it is detected that one of the defined slave axes is a main axis, this means that it has the axis index 0, 1 or 2. For further information see [PROG// Section: Synchronous operation]
Response | Class | 2 | Abort NC program processing.
Solution | Class | 3 | Check and modify NC program. Make sure that the slave axes are not main axes when synchronous operation is selected. Check the defined coupling groups and axes exchange commands possibly used before.
Parameter | %1: | Logical axis number [-]
Axis number of the invalid slave axis
Error type | 1, Error message from NC program.