First, put a knob on the front panel and right-click-Properties. Find the data type and change it to U8 or U 16 or U32. As long as it is an integer variable, the files are discontinuous.

Then, on the page of text label in the property, check "Use text label as scale mark" and change it as shown in the figure.

After this confirmation, an annoying thing will appear on the front panel. You can right-click the knob-Display-Text Display to check it.