LabVIEW and Siemens s7300

[Bharadwaz]

Hello,

I would like to develop add on application in LabVIEW 2013 for one of our systems which is controlled by Siemens S7300 PLC. There is an third party software(Maximator) installed onto the PLC. There is no status file or text file generated by the software, such that I can extract the data into LabVIEW and display them. The PLC is connected to the PC through TCP/IP.

I am new to PLCs

My question is

If I connect to the PLC via LV and read the status of the I/O modules using TCP/IP Communication, will I over write the exisiting third party software on the PLC ?

Kindly help me how can I extract data from the PLC or Maximator software without disturbing both of them?

Will data logging using RS232 will work?

Can S7300 communicate with LV and Maximator simultaneously.

Thanks

bharadwaz

[pallen]

Reading data from your PLC will not overwrite anything.

Have a look here:

Connect LabVIEW to Any Industrial Device, Network, and PLC

And here OPC

[Stephan_D]

Hey bharadwaz,

the information of Patrick are very usefull to get an overview about the topic.

I also don't think that you will overwrite the software on the PLC if you use TCP/IP to communicate with your PLC

I think it would be a good idear to ask the same question on the Siemens an Maximator forum. They can tell you which acces points are available and the people in the LabVIEW forum can help you to realize the communcation in LabVIEW.

Regards, Stephan

[JoeMoore1331]

The Siemens protocol is well documented and there is lots of support out there already - see https://forums.ni.com/t5/Example-Code/S7-PLC-TCP-IP-Protocol-Reference-Example/ta-p/3492191#comment-... for an example.

With something like the code posed above you can read certain memory locations to get the data you need. 

The software on the PLC is just the program, this protocol can't overwrite it. I'm unsure if the PLC just runs on its own or if you have some kind of SCADA system attached? I'm not sure of the maximum number of connections you can have to the PLC but it shouldn't be a problem either way.

You could use 232 instead, there must be labview stuff available for it but the adaptors for Siemens stuff can be quiet expensive.

The manufacturers aren't normally very supportive of other people modifying their code though, they may not tell you the memory locations you need and the PLC could be passworded (You can get around the 300 password but it depends on the level the PLC is locked to)

[Bharadwaz]

Hello,

Thank you Patrick for the valuable info, I have seen the web cast previously. And the opc client was also very helpful.

@Stephan Thank you for the suggestion, I shall post it in the PLC maximator forum

But is it not like, only one application on a PC can access the TCP/IP port, i.e Maximator and LV simultaneously cannot use the port? Please correct me if I am wrong?

@Joe

Thanks for the example program link.

The alternative which I am thinking is, I only have to monitor one channel which sends a 5v dc high or low signal.  I just read this signal using a DAQ (eg USB 6000).

I feel this will work ?
kindly suggest

Thank you all

Regards

Waz