Manchester encoding is a type of digital encoding that is used in data transmission. Within the structure for Manchester encoding, the data bits in the transmission are represented by a series of states that occur in a logical sequence. This approach to data transmission is somewhat different, as many encoding methods tend to assign a high or low state of voltage to each bit and use that information as the criteria for effecting the transfer of the bits.
Along with a difference in the way data is recognized and transmitted, Manchester encoding also involves the setting of certain perimeters that impact the transmission process. First, there is a default in place for the length of each data bit included in the transmission. Because of this default, the end result is that the transmission signal involved with Manchester encoding is self-clocking.
Second, the structure for Manchester encoding determines the state of the bit based on the direction of the transmission relative to the placement of the bits. Essentially, this transition may go in a direction of low to high, or high to low. The direction will often depend on the system receiving the data, and will vary. Manchester encoding allows for this variable and functions accordingly.
One of the main advantages to using the Manchester code approach to data transmission is the self-clocking component. This process of synchronizing and timing the rate and direction of the transmission can help to reduce the chances for several types of data failure. Most notably, Manchester encoding helps to reduce the overall error rate during the actual transmission, which helps to preserve the integrity of the data. Manchester encoding also is understood to enhance the overall reliability of the transmission, due to the perimeters that are in place to govern the rate and timing of the transmission.
Along with the advantages of using Manchester encoding, some programmers do note one potential disadvantage to the process. Manchester encoding involves the transmission of more bits of data than were part of the original data signal. While this does not tend to cause problems in many cases, there are those that believe the inclusion of additional bits can impact the integrity of the data in ways that are not readily apparent at the time of transmission.