Hi, When casting and int to two char' (a MSB and LSB) is it safe to do the following:- Data[7] = (Channel_One >> 8); Data[8] = (Channel_One); Or am i best doing: - Data[7] = ((unsinged char)Channel_One >> 8); Data[8] = ((unsinged Char)Channel_One); or Data[7] = (((unsigned char)(Channel_One & 0xF0)) >> 8 ); Data[8] = (Channel_One & 0x0F); Andy