I finally got my Hamilton handheld (TT120EKR2-1) to work with no help from Hamilton support. Hamilton support always blamed the $411 handheld unit (which I have 2 of) saying there was a problem with them. Of course Hamilton is not allowed by the manufacturers of the handheld to repair the handheld. So support just recommends to replace the handheld, never mentioning the data cord, which I already had a problem with. So I got a replacement data cord and everything worked great.