ABB FPBA-01 Instrukcja Użytkownika Pobierz pdf (Strona 63)

Communication

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 13. 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.

1 2 ... 58 59 60 61 62 63 64 65 66 67 68 ... 125 126

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ABB FPBA-01 Instrukcja Użytkownika Strona 63