Communication
73
PROFIBUS SD2 telegram for Default SAP (0) and SAP 58-62
PROFIBUS typically uses SD2 telegrams for DP communication.
The structure of an SD2 telegram is shown below.
Figure 7. PROFIBUS SD2 telegram for Default SAP (0) and SAP
58-62
DP header DP trailer
SD LE LEr SD DA SA FC *DSAP *SSAP DU FCS ED
68h x x 68h xx xx x xx xx x… xx 16h
SD = Start Delimiter
LE = Length
LEr = Length repeated
DA = Destination Address
SA = Source Address
FC = Function Code
*DSAP = Destination Service Access Point
*SSAP = Source Service Access Point
DU = Data Unit for DP services
FCS = Frame Checking Sequence
ED = End Delimiter
*Not present with Default SAP (0)
Data Unit
See tables in descriptions of each SAP on following pages.
To Next Page
Loading...
Need help?
General
