hello to all members, well first thing is i m new to embedded system programming so sorry in advance for any mistake.The problem that i m having is that i m using mini2440 ARM9 board with WinCE n trying serial communication using MODBUS protocol i've written code in vb .net 2005 using serial class provided with .net, after compile ther is communication between pc's hyper terminal and board but when i try to communicate with emulator like MODScan or any other then nothing is happening.i mean whether i try to query slave for either read or write ,coil or register (board as master) then there is no responce from either 1. i cant get what the problem or where the problem is whether H/W or S/W ?? thanks in advance Regards kapil
problem in serial communication mini2440
What hardware layer are you using for the modbus? If your using rs485 how did you connect it and what type of converter are you using?
hi to all members thanks Edje11 for reply but i figured out what the problem was.yes i m using RS485 converter for serial rs232 port communication.any ways thanks once again. but can u tell me (now when serial communication is done) is there any way that i can access different ports like ADC etc or different port addresses using vb .net2005 for programming. Regards kapil