Knowledge base Automation Systems Networks

Why can you not upload a configuration from a Profibus Master or Profinet IO-Controller

Modified on Sun, 11 May, 2025 at 10:26 PM

The configuration of the network devices is contained in the master.

The Configuration tool downloads a parameter and configuration string for each slave to the master. The parameters are there to set for example an analogue input to 4-20mA or 0-10V. The configuration string sets the I/O-size. Nothing is stored in the slaves themselves.

At startup of the network the master or IO-controller will set the parameter and configuration string to each and every slave device it has in its scanlist. The slave device on its turn evaluates the parameter and configuration string and will notify the master if the data is correct and that it can work with that. The master has no clue what the actual content is of the parameter and configuration string.

Then if the tool uploads the configuration from the Master or IO-controller it must reconstruct everything from just a binary file. The source to find out what is what is the GSD-file of the device. But you would find that there a many possible combinations. If the slaves are simple it could be possible. But for complicated slaves like modular ones it could be that it is virtually impossible.

Example. I have a 16-bit counter input and a analogue input. Both are 1 word in size. But parameters are completely different you can imagine. The configuration read from the IO-controller, look this is a word input. And this are the parameters. The tool finds in the GSD-file two input types with the same code for word. And now which parameters to choose.

You see, almost impossible and in some cases not possible.