7 Programming FCs (Functions) and FBs for S7 Ethernet CPs
A-196
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Case b: Sequence with newer CP types (S7-300 only!)
The send job is started as soon as the parameter ACT = 1 is passed.
In contrast to case a, the protocol used here to transfer the data segments
(each 240 bytes of user data) requires the FC to be called again for each
segment.
Depending on the length of the user data, you must therefore continue to call
the FC with ACT=0 until transfer of the entire data record is indicated; at least
one call with ACT=0 is always necessary. The data is transferred to the
communication partner in segments of 240 bytes.
The status code in the output parameters DONE, ERROR and STATUS is
updated in each block call and can be evaluated.
Transfer of field n-1 active
over Ethernet
Job active
1)
AG_SEND
Transfer of field n active
over Ethernet
User program
(CPU cycle)
Ethernet CP
Communications Partner
AG_SEND
Job active
1)
Job active
1)
AG_SEND
Supply AG_SEND with
data “X”
ACT = 1
Transfer of field 1 active
over Ethernet
Legend:
1)
Parameter transfer DONE, ERROR, STATUS
Time Time Time
Supply AG_SEND
ACT = 0
AG_SEND
Job active
1)
Transfer of field 2 active
over Ethernet
Job completed without error
1)
AG_SEND
Data record X is
transferred in
segments.
FC5 AG_SEND / FC50 AG_LSEND - continued
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