I am having problem to write program(Down load) on FX3U-80M mistubhishi PLC using USB to serial converter since my LAPTOP is not having serial port.But in my other PC which one is having serial port I am able to down load the program.Using same USB to serial converter I can download E-300 beijer MMI from same lap top.I am using the followng procedure to download program from laptop to PLC using GXdeveloper version 8.Online > transfer Setup.Following message is displayed cannot communicate with PLC execute again after checking the connection with PLC <ES:01802007>.Is any guy help me how to down load using USB to serial converter?