Check the ADC-16 on a different PC, does it still give you the same results.
When you checked the voltage you did connect the ADC-16 and then start Picolog, before testing the voltages.
Have you checked the conformity of the serial cable that you are using. It should be straight through.
If you have checked all this and the unit still will not work then we will need to get it back so that we can investigate its problem. To do this I will need your contact details, so that I can give you a returns number. Please email me these details to: