Linking to Other Systems with FETCH/WRITE
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SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
a) Structure of FETCH Frames
The meaning and values of parameters shown without values in the following table
can be found in the section “Parameter Values“.
FETCH request frame FETCH response frame
0System ID =”S” 0 System ID =”S”
1 =”5” 1 =”5”
2Length of header =16d. 2 Length of header =16d.
3ID OP code =01 3 ID OP code =01
4Length OP code =03 4 Length OP code =03
5OP code =05 5 OP code =06
6ORG field =03 6 Ack field =0Fh
7Length ORG field =08 7 Length ack field =03
8ORG ID 8Error field =No
9DBNR 9Empty field =FFh
AStart address High Byte ALength empty field =07
BLow Byte B
CLength High Byte C
DLow Byte D free
EEmpty field =FFh. E
FLength empty field =02 F
Data up to 64 K but
only if Error no. =0