Siemens SINUMERIK 840D Function Manual page 705

Application example
The "Handwheel override in automatic mode" function is frequently used on grinding machines.
For example, the user can position the reciprocating grinding wheel on the workpiece using the
handwheel (path default). After scratching, the traversing movement is terminated and the
block change is initiated (by activating DB31, ... DBX2.2 (delete distance-to-go)).
Preconditions
In order to activate "Handwheel override in automatic mode", the following requirements must
have been met:
● A handwheel must be assigned to the axis in question.
● Pulse weighting exists for the assigned handwheel.
Handwheel assignment
The assignment of the connected handwheels to the axes is analogous to the "Manual
traversing using a handwheel (Page 651)" via the user interface or via the PLC user interface
with one of the following interface signals:
● Machine axes:
– DB31, ... DBX4.0 - 2 (activate handwheel)
● Geometry axes:
– DB21, ... DBX12.0 - 2 (geometry axis 1: Activate handwheel)
– DB21, ... DBX16.0 - 2 (geometry axis 2: Activate handwheel)
– DB21, ... DBX20.0 - 2 (geometry axis 3: Activate handwheel)
If handwheel override is programmed for an axis to which no handwheel is assigned, a
distinction is made between the following cases:
● For velocity override:
The axes traverse at the programmed velocity.
A self-acknowledging alarm is output (without response).
● For path definition:
No traversing movement is performed because the velocity is zero.
A self-acknowledging alarm is output (without response).
Note
For the velocity override for path axes, only the handwheel of the 1st geometry axis is
applied to the path velocity.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
H1: Manual traversing
17.13 Use of handwheels in automatic mode
705