I claim the ornamental design for an operator panel, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a top view of an operator panel, showing my new design; and,
FIG. 2 is a top perspective view thereof.
The Siemens name plate forming part of the claimed design is a registered trademark of Siemens Corporation.