hai guy, i got big problems:- i using Acer laptop using usb port, OS is a windows XP, my big proble are:- i can't communicate using vb 6 + compolet version 2 to control the PLC CQmIH, CPU 51. when i used CX-programmer with the same laptop and USB port and PLC can communicated, when i try to used vb and compolet there nothing single will produced. plese help me tq for helping me, cypol