Connect PC to PLC S7-200 Siemens


Thread Starter


Hi friends,

I am using PLC S7-200 for concrete mixing. I want to communicate PC with it using Micro Computing ActiveX. It is to be connected through COM port by PPI cable. My program (in Visual Basic) is reading some data (about 10 REAL, 5 INTEGER, 3 BOOLEAN numbers, update time: 500ms) from PLC and writing some commands (4 BOOLEAN numbers) to PLC. I made those connect by programming. My problem is:

+ Sometimes communications is lost, my data can not update.

+ In my program, When I received the ended batch command (read from PLC with a Boolean value), I will disconnect the MicroComputing. But when I do this, my program is shut down immediately.

Anybody know this. Please help me.



Ranjit Nambiar

Hi ,
this problem occurs and we had a similar customer who was trying to do this , I would suggest you to use LabVIEW with Datalogging and Supervisory control toolset whichc has builtin drivers for PLCs and can make your project comission fast .
let me know if you need any further help .