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Break Signal? No response after Init Protocol FB


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Ascii and binary requests from PC to V350PLC via serialport (direkt|gsm-|landline modem) works fine with my VB.Net App,

based on Vision Communication.pdf!

The response is, what i asked for....

But on "Alarm" the PLC must connect the sleeping PC-COMPort for pop-up an ugly, red window.

So i added to the ladder a Protocol FB to Com2 . The Init of this FB is normaly realized with SB2. For the test

i used the "F4" key.

If alarm-MB rises the PLC calls via Modem at COM2 and "Protocoll Send" well-behaved the PC and sends his Message...if it's done,

"HangUpFB" terminates the line.

The Problem:

After initializing the Protocol (PCOM)FB there are no responses for any following requests from my .Net App.

Re-initializing of the COM2 FB terminates the line and skip the Protocol FB out. After that and recall the PLC, the requests generate responses but

ProtocolSendFB doesnt work. I don't believe that this is a way...

Testing the VB.Net example with the unitronics CommDrive DLL:

It works fine, without the problems described above, but i don't find the way how to implement the AT- commands for connections via modem...

Connecting via VisiLogic "online Test "( F9) ...send break signal---connecting...


The Questions:

- Defeat the PLC-COM with a "break signal"? What is the Code for?

- Whats behind the Function of SB 330-333


-How to use commDrive.dll (serial() Class) with modems? (atd+49123456....)



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