Hi, sir you seem to be the man to answer my quest and I thank you in advance so what is my problem it is about a vfd HuanYang model GT-7R5G-2 when trying using RS485 Modbus that I can't get to work. First let me explain my setup with parameters set on keypad no problem vfd work fine meaning run,stop,increase,decrease with those parameters P0 00 set 0, P0 01 set 0, P0 07 set 0. Second on page 84 of the Gt-series manual it say Comm protocol is RS-485 Asynchronous half duplex with default 8-E-1- 19200 bps, I have set those parameters as so PC 00 set 1, PC 01 set 4, PC 02 set 1, and reset P0 00 set 0, P0 01 set 2, P0 07 set 7 . to verify if comm is working I am using COMMIX 1.4 software on my Windows PC and the VFD with a CH340 USB to RS485 converter and here is the command send 01 06 10 00 01 through the Commix software to try to start the vfd see the screen shot included below, it does not, pulling my hair and searching why it does not work, is it parameters, converter I even interchange the 2 wire on the converter with no more success. Note my spindle is a 3.5 kw 220volts 300hz 18000rpm. I hope you can help and shed some light on a desperate man, again thank you.