Profibus DP S7 300 Siemens PLC to communicate to LabView 8.0 without using opc server

[Duck hunter]

Does anyone know of a way to communicate with Siemens PLC s7 300 PLC and Step 7 software to LabView 8.2.1 without using a opc server. I'm currently using a opc and it works but it is to slow. Looking for a faster way to move my readings for Siemens to Lab View.

[waldemar.hersacher]

I know of system using products from deltalogic http://www.deltalogic.de/content/view/21/38/lang,en/ to interface LV with S7-300 and interface cards from Hilscher. I was involed in analysing such a system for an update.

[Duck hunter]

could you go into a little more detail on how you would do this with out a opc server?

[waldemar.hersacher]

The above mentioned product is talking directly over the Hilscher Profibuscard to the PLC. We needed to know the number of the datablock within the PLC and the byteoffset and length within that datablock. There are conversion functions to convert the read bytes into LV datatypes and vice versa. Reading and writting used the datablock number, offset, length and an array of U8.

For a good perfomance you need to put the variables which are used together int consecutive space in the data block of the PLC.

[Duck hunter]

thank you i will give it a try.

[Paul M.]

Hello,

We also just started selling PROFIBUS interfaces which come with a LabVIEW API for bringing data directly into LabVIEW.  This will be the fastest way.  You can get these interfaces from http://ni.com/profibus

[waldemar.hersacher]

Hi Paul,

I know this fact from a recent marketing update we had by NI representatives. I wasn't sure before getting the information by email if this was part of the secret announcements or already available.

[Duck hunter]

HI Waldemar and Paul,

Paul how would you connect the interface to a Siemens PLC that is already running? I do know that it you want to communicate between two or more independent PLC systems you would have to use a DP TO DP coupler or use the MPI ports on the PLC. Would you treat this like another PLC and couple it?

Duck hunter

[Aashish_M]

Hi Duck,

Please refer to the below articles:

Profibus Overview

[broken link removed]

Using an Applicom Profibus Board

[broken link removed]

Hopefully these will help you get started.