Thank you for your quick answer. I forgot to write my version of IgoPrimo. It is Primo 2.4.0 ver. 9.6.13.267029 - 06.11.2012. Values for port and baud in sys.txt i have ''auto'' in both is it correct ?. Do you think this version of primo is unstable ? Should i try another one ? Do you have any suggestions which version should i try ? I am very sorry for my stupid questions but i am totally green in this topic