Siemens 7 - Manual (Page 33)

Multiplexer Driver Developer’s Guide
7.4 Data Transfer
s
Mux_Drv_DevGuide_v07 Page 33 of 36 2006-9-27
Confidential / Released
Figure 9: Send function from the virtual communication ports
Send function from the virtual Communication Ports
(the SerPort Object)
Function SerMuxSend() only sends UIH-Frames (unnumbered
information) which come in from WriteRequest to the virtual serial
communication port.
Start
GetFrameBufferPort
Frame ?
WrSubmitWriteBuffer
asked all Port two
times and no Frames
sent?
ret
WrGetWriteBuffer
Get
WriteBuffer?
WrReturnWriteBuffer
no
no
yes
yes
no
GetBuffer?
yes
no
yes