Hi Joe, You did not say by which method you are using-is it the older method 'Bisync' or 'HDLC' i.e.ISO 3309 or similar SDLC. If HDLC note that the data is transmitted as blocks transmitted as blocks which are framed by special framing character. the basic element is a bit.How these bits in the data area of the block are used is left up to the provider of your application.(generally either grouped as 8-bit bytes or 16-bit words) Start and end frames are demarcated by a unique character (e.g.8-bit sequence). Or are you using XModem which uses ASCII but has a no of inherent weaknesses. Bill
