PROFIBUS Manual

Zoom Window Out
Larger Text | Smaller Text
Hide Page Header
Show Expanding Text
Printable Version
Send Mail Feedback
Save Permalink URL

Navigation: FDL: data transmission > Protocol definitions

MBP coding

With Manchester coding every bit is coded as a change of level. In this case, a positive change is value "0" and a negative change is value "1". If necessary, an additional change of level will occur between the bit times. This is shown in the diagram below.

Manchester - Code

Manchester code has the advantage that the bit clock can be obtained directly from the signal, so that every bit is re-synchronized. This allows an entire telegram to be transmitted without additional synchronization signals. This type of transmission is called synchronous.

Since every bit always consists of equal proportions of positive and negative signal, the average value of this signal is always constant. This average is now used to supply the devices. This is where the name MBP comes from: Manchester coded Bus Powered.