Siemens simatic s7

Hello guys,

during a (very short) project on our faculty of my highschool I was asked for a project on the s7 (and other plc's).
The question of a installation company was: is it feasible to read out the status (in and outputs) from the plc. The Siemens S7 is common used, but others are used too. I was wondering if I could find a manual how to read the status (for emaxple in visual basic or c++). I am using a TS module, so my s7 is connected to the pc through the COM port (RS-232 serial data).

If anyone can help me out I would be very grateful.


Kind regards,

Dave

not step7

forgotten, I don't want to use step 7 or some other software, because I only want to read the plc's status. Step 7 is much too expensive...... So I need to write the software myself.

Dave

Dave,

if you want to read the status of the I/O (and internal bits, timers, counters, etc.) you need to know the MPI protocol. Since you don't want to buy the STEP 7 software, it is impossible to implement another communication standard on teh S7 PLC.

The MPI protocol is a very well guarded secret with Siemens. It's even better guarded than fort Knox ! Yhe only thing commonly known about MPI is that it is using RS485.

The only other solution is to buy a DDE or OPC driver to get access to the internals. There are different possibilities:

• Applicom has a FastDDE driver and a SuitLink driver (only for WonderWare ???).
• ATS also has a FastDDE driver. You can download a demo.
• Merz has an OPC driver. You can also download a demo and the manual.

These are the ones I know about. By searching the net for MPI and OPC or DDE you might find more.

Kind regards,

someone

Hello thanx for your request,

i knew it was guarded, but isn't there anyone who knows the protocol? I guess there are a lot of people who wants to know it...

Dave

Hmmm i think this is what you are looking for. http://omarz.htmlplanet.com/What_is_Prodave.htm

Check out http://www.runmode.com/ aswell.

thanx

Yes thanx,

I had ProDave and finaly I can connect. Hope that I can read what I want. If not, I'll let u know.

Dave