first thank u so much i can join on this forum, plc is great for me. now, i have some problem that i never know it before, it's about comunication between pc and cj1w etn21, few days ago my display data on cx supervisor in pc lost and be the#### display. after it i restart my plc n it be normal again but it happen again more often than before until my cj1w etn21 erh led flashing. i try to ping is good conection but sd, rd, tcp led on etn21 modul not lit sudenly and my display lost again. my last efort is i try to set node number on etn21 modul and the erh eror flashing is gone but i can conect my pc again to etn21 modul. so, i set back the last node number and can display again but erh back flashing n data lost sudenly aaain. can you help me please?