MCV_GrpBackward
This FB causes the NC kernel to move backwards along the programmed path.
For further information on backward motion, see the functional description [FCT-C7].
Block diagram

FB parameters
| VAR_IN_OUT | ||
| Variable name | Data type | Description | 
| AxesGroup | AXES_GROUP_REF | Axis group reference | 
| VAR_INPUT | ||
| Variable name | Data type | Description | 
| Enable | BOOL | The axes move backward on the path as long as the input is TRUE. | 
| VAR_OUTPUT | ||
| Variable name | Data type | Description | 
| Valid | BOOL | TRUE indicates that backward motion is active. | 
| Req | BOOL | Indicates that another function commanded backward motion e.g. a GUI. This command only becomes active when it is applied to the “Enable” input of the FB. | 
| State | BOOL | TRUE indicates that backward motion is activated. | 
| Error | BOOL | Indicates TRUE when an error occurs. | 
| ErrorID | UDINT | Error identifier |