kapil 
hello to all members, i m using mini2440 with WinCE.i've written a code in vb .net2005 for mini2440 for serial communication using MODBUS protocol.now when communicate my board n a modbus slave then there is no issue everyting goes fine but when i trying it with my actual machine then there seems to be no communication at all,i can't even trace if query that i m sending is accepted ,rejected, or any other error because there is no responce from the slave machine(which is a VLT FC51 drive). thanks in advance Kapil