hi everyone, good day to all.today i fix the problem after long struggle. i switched off the 5th pin in plc,then select rs-232c in pc setup,also modifided databit,parity and stop bit as 9600,8,1,none. after that i wondered,the plc send the string as i require(FC 40 32 00 91).the driver also respond that and it control the motor as my wish. thanks to all of u for ur guidence,