VIPA System 300V - Page 129

Manual VIPA System 300V Chapter 6 Deployment CPU 31x with TCP/IP
HB130E - CPU - Rev. 11/50 6-39
For every READ and WRITE the CP generates PLC header for request
and acknowledgment messages. Normally the length of these headers is
16Bytes and have the following structure:
Note!
Please regard that the pointers for the start address of the CPU 31x from
VIPA are -not like the S5 from Siemens- pointing to a Byte area. The length
assignment is via a word!
Structure of PLC-
Header
for WRITE
Acknowledgment message
System identifier ="S"
="5"
Length of header =16d
Ident. OP-code =01
Length of OP-code =03
OP-Code =04
Ack. block =0Fh
Length of Ack-block =03
Error No. =No.
Dummy block =FFh
Length of dummy bl. =07
not used
Request message
System identifier ="S"
="5"
Length of header =16d
Ident. OP-code =01
Length of OP-code =03
OP-Code =03
ORG-block =03
Length of ORG-block =08
ORG identifier
DBNR
Start address H
L
Length H
L
Dummy block =FFh
Length of dummy bl. =02
64K data only if error no.=0
Acknowledgement message
System identifier ="S"
="5"
Length of header =16d
Ident. OP-code =01
Length of OP-code =03
OP-Code =06
Ack. block =0Fh
Length of Ack-block =03
Error No. =No.
Dummy block =FFh
Length Dummy block =07
not used
64K data only if error no.=0
for READ
Request message
System identifier ="S"
="5"
Length of header =16d
Ident. OP-code =01
Length of OP-code =03
OP-Code =05
ORG-block =03
Length of ORG-block =08
ORG identifier
DBNR
Start address H
L
Length H
L
Dummy block =FFh
Length dummy block =02