A method and system to improve the retention of synchronization between the transmitter and receiver of image data across a communication channel. If the control character designating the end of the line of data is corrupted, the receiving system will not recognize that the line of data has ended and will continue as if data is still being received. The corruption of a single bit in the control character will cause the receiver to misinterpret the end of line control word. Since the receiving logic does not realize the transmitter is no longer sending data, erroneous data will be stored in the storage elements. By using an alternate control character as an additional end of line indicator, the receiver will terminate the line of data and will wait for the next start of line control character from the transmitter. Synchronization between the transmitter and receiver across the communication channel is thus maintained.