SP7: Priority of the communication protocol

[Matthias_H.]

Hello,

does the toolkit use the S7-Online protocol? This protocol is low priorized on the S7 because it's the protocol of the operation panel. And a fast communication is not guaranteed. And this protocol is not documented. But some smart people did reverse engineering and so it's working but Siemens won't support it.

There is a free toolkit with this functionality: https://decibel.ni.com/content/docs/DOC-5467

This kind of communication is slower than the native one with low level TCP/IP.

But with the low level TCP/IP communication you have to do the implementation on both sides: LabVIEW and S7. I use it, because it's much faster and the new S7 PLCs (S7-1200, S7-1500, ...) will communicate in this way, too.

Which kind of communication does the SP7 toolkit implement?

Regards

Matthias

[Peter-daq.io]

Hi Matthias,

we do use the online protocol. It is perfectly apt for the following usage scope:

- LabVIEW users who have no to limited knowledge of PLC programming

- users who want to or need to share data with a S7 (200/300/400) PLC

- users who don't want to or cannot re-program the PLC

- users who would like to get started quickly

The "toolkit" you mention is not an actual toolkit, it is a set of useful VIs to get started. Kudos for the work that went into that! You can find rather thorough documentation on the Online Protocol, although not supported by Siemens as you correctly stated.

When we developed SP7, we wanted to provide a more complete solution and a more comfortable starting point for inexperienced users than what was available so far. For example, all of our write functions make sure their value was actually set. That means, even though the PLC might be busy and the online protocol might have to wait some milliseconds, we make sure the required commands will be executed in the end.

From our experience, most applications involving LV and S7 do not require real-time capability or high-throughput data streaming. OPC servers can be expensive and slow, as well.

As we are moving forward, we will be working to support other modes of communication and a larger set of devices. We are certain that - for the time being - we provide a good solution for a range of application areas. Users can try SP7 out for free and evaluate if it will work for their application.

Cheers

Peter

[Matthias_H.]

Hello Peter,

thank you for your answer!

You're right, OPC is relatively slow and if you don't need an extremely fast communication the S7-Online protocol is enough. I myself have much knowledge in programming LabVIEW and Step 7. But if you don't have it or you won't touch a running PLC program, this kind of protocol is a nice solution to share some data, that's right.

Regards

Matthias

[LeoEiranova]

Hi Peter and Mathias:

Unfortunately, I am not that far using the SP7 package, I have not been able to connect to the PLC, I have tried installing all the versions (currently I have the latest (1.8....) and I still experience the same problem, Error 62...see the attached file with all the information regarding the VIEW error.

What am I doing wrong?, what is not set?, why the error, and how can I move forward?

You could contact me at leiranova@aavid.com

Your help is highly appreciated.

Thanks in advance!