Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 212)

Linking to Other Systems with FETCH/WRITE
212
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
a) Structure of WRITE Frames
The meaning and values of parameters shown without values in the following table
can be found in the section
“Parameter Values“.
WRITE request frame WRITE acknowledgment frame
0 System ID =”S” 0 System ID =”S”
1 =”5” 1 =”5”
2 Length of header =16d. 2 Length of header =16d.
3 ID OP code =01 3 ID OP code =01
4 Length OP code =03 4 Length OP code =03
5 OP code =03 5 OP code =04
6 ORG field =03 6 Ack field =0Fh
7 Length ORG field =08 7 Length ack field =03
8 ORG ID 8 Error field =No
9 DBNR 9 Empty field =FFh
A Start address High Byte A Length empty field =07
B Low Byte B
C Length High Byte C
D Low Byte D free
E Empty field =FFh. E
F Length empty field =02 F
Data up to 64 K