Basic Principles of Serial Data Transmission
2.4 Data Transmission with the 3964(R) Procedure
PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03
33
2.4.2
Block Checksum
Block Checksum
With the 3964R transmission protocol, data integrity is increased by the additional sending of
a block check character (BCC).
%&&ඎ
;25
;25
;25
;25
+ඎ+ඎ+ඎ+ඎ+ඎ+ඎ+
67;
%&&
'/((7;
'DWD
0HVVDJHIUDPH
Figure 2-5
Block Checksum
The block checksum is the even longitudinal parity (EXOR operation on all data bytes) of a
sent or received block. Its calculation begins with the first byte of user data (first byte of the
message frame) after the connection setup, and ends after the DLE ETX code on connection
release.
Note
If DLE duplication occurs, the DLE code is accounted for twice in the BCC calculation.
Содержание SIMATIC CP 340
Страница 6: ...Preface PtP coupling and configuration of CP 340 6 Manual 04 2011 A5E00369892 03 ...
Страница 10: ...Table of contents PtP coupling and configuration of CP 340 10 Manual 04 2011 A5E00369892 03 ...
Страница 186: ...Accessories and Order Numbers PtP coupling and configuration of CP 340 186 Manual 04 2011 A5E00369892 03 ...
Страница 190: ...Literature on SIMATIC S7 PtP coupling and configuration of CP 340 190 Manual 04 2011 A5E00369892 03 ...
Страница 200: ...Index PtP coupling and configuration of CP 340 200 Manual 04 2011 A5E00369892 03 ...