how to set sell tax for uniwell nx-5400-01?

Do you have the manual for your register? If you do, look up program 107 to set the tax rate. Also, you should look at program 200. This is where you set the PLU flags, particularly PLU flag 2, which determines what tax rate is applied to a given PLU / item.

If you don't have the manual, post again and I'll give you more explicit instructions.

Steve
January 2010