Kipp&Zonen COMBILOG Data Logger - Manual (Page 120)

ResDataUnit: Response-Data-Unit (length = 0 ... n byte):
The Response-Data-Unit identifies a data field in the response
telegram which contains the data for the calling communication
partner.
FCS: Frame-Check-Sequence (length = 1 byte):
The Frame-Check-Sequence FCS identifies the check sum of
the telegram. In the PROFIBUS-protocol this is the sum of the
ASCII-values from DA to DataUnit
modulo 256:
CheckSum_PROFIBUS = [DA+SA+FC+DataUnit] mod 256. In
the PROFIBUS-protocol the value is stated as a hexadecimal
value (hex 00 .. FF).
ED: End-Delimiter (length = 1 byte):
The End-Delimiter ED identifies the end of the telegrams. In the
PROFIBUS-protocol it has the value hex 16.
SC: Short-Acknowledgement-Frame (length = 1 byte):
The Short-Acknowledgement-Frame SC identifies a telegram
that can be sent back to the communication partner as an ac-
knowledgement. With SDA-requests it can be used as a posit-
ive receive acknowledgement. With SRD-requests it can be re-
turned as a negative acknowledgement.
Hardware Manual COMBILOG 1022 120