they work but when I start the machine in the morning they can take up to a minute to show the stop on the software. they light up right away but the software does not show they are active for a bit. it used to be a second or two but it can take up to maybe a minute for them to work. I have had them light and not work if a wire came loose in the box but they do work once going. but it can be a bit for the software to show they are working. once in a while they wont work right away if I rezero later in the day but they start again the second try.