Thanks for the help dubble. I know this is a forum for UCCNC support and not Chinese vfd 's. I had PD001, and PD002 set to 1 for external control. And i had PD070 set to 0. And as I posted earlier it didnt work. I think its closely associated also with parameters PD0070 through PD0076. I changed them to values suggested in the manual and was going to try them when my computer hard drive failed! It will have to wait a couple days until i get a new computer.