beautypg.com

Figure 9, Send function from the virtual communication ports, Multiplexer driver developer’s guide – Siemens 7 User Manual

Page 33

background image

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