Hi Naoto. Thanks for your reply.
Can I just tutn XON Xoff off and how wold I do this with MSCOMM32
regards.
Gerard




>Do you have handshaking enabled (in particular XON/XOFF) ? If the data transmitted is in binary, there is a possiblity that XOFF character could occur which might cause one side to stop transmitting until XON character is received.