Programming FCs (Functions) and FBs for S7 Ethernet CPs
153
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Notice
Please not the following special feature on TCP connections:
With the S7-CPs for S7-400, you must use FC AG_LSEND on TCP connections!
With the latest S7-CPs for S7-300, you must also use FC AG_SEND for TCP
connections.
How the Block Works
The following diagram illustrates the normal sequence of data transmission
triggered in the user program using AG_SEND.
The send job in executed as soon as the parameter ACT = 1 is passed.
Following this, the parameter ACT = 0 must be passed in at least one further call.
The status code in the output parameters DONE, ERROR and STATUS is updated
in each block call and can be evaluated. To update the status code without starting
a new send job, start a new block call with the parameter ACT = 0.
Refer to the sample program at the end of Section 5.3.1.