Sorry for the late response did not get the notification that the reply was posted :S i'm trying to implement MDB for vending devices, coin acceptor device. protocol is: http://www.vending.o...B_Version_4.pdf And it statest that master controls slaves and the communication is like this: 8 data bits 1 mode bit = 9 bits to travel. When master is addressing the slave sets mode bit to 1 meaning [ADDRESS + modebit(1) =9bits]+[data for slave+modebit(0)]+... When slave responds the last BYTE sent has modebit set to 1 so that master knows that this is the last byte in the transmission like ETX in the normal uart comm. That is what i'm trying to do on the netduino. I know how to intiate master -> slave with parity mark, space, but the problem is on receive, because i cannot detect the mode bit = 1 on the last byte so that i know that we have end of transmission. Problem is in variable data len in response, where u need the detection of the modebit = 1. Best regards,

Can you explain using xon xoff? I have tried mark/space parity on linux but the problem is always with the receive, because parity check for MARK never works at least it did not work for me :S How can this be achieved by xon*xoff? Thank you!!!

I'm in the process of integrating a coin acceptor that runs on MDB (multi drop bus) which uses 9 bit communication. 8 data bits and 9th mode bit which is used for addressing a device on MDB and for detecting end of transmission from device to master. Now before i start cuppling everything together i need to know if it is possible to use 9data bits with NetDuino. And how to use 9 data bits... how to use send what data type do i pass to send or is then for sending a 9bit data needed 2 bytes or how? Hope somebody knows Best regards