how to access the memories of clp schneider M221 via MODBUS TCP/IP

Hi Joao Marcelino ,

Typically you would define variable tags or UDT's within the PLC and allocate an address.

Once the PLC programming is complete, you can export the tag list, then import into your SCADA product. Configure your Modbus TCP/IP driver and then use the tags in graphics, alarming and trends.

It might be best to post this question within the AVEVA Edge forum. As they could give you specific information related to AVEVA Edge driver configuration.

(+) Aveva Edge Community (Formerly InduSoft Web Studio) - AVEVA Software Community

Kind regards

Olivier

Hello João

If I remember well, the trick of these small PLCs from Schneider is that they just have the memory addresses that are defined in the PLC.

For instance if you have a TAG at %MW1 and another tag at %MW3, but no tag defined at %MW2 that address will not exist in the modbus. When you define the tags in Citect the modnet driver will try to read the range from %MW1 t to %MW3 for performance, but the PLC will give an error because the address %MW2 doesn't exist.

So you need to tweak the modnet driver to read just the addresses configured and not ranges, I don't remember the parameters, maybe block=1 will to it

No need to tweak the driver's parameters. To enable this behaviour you have to prefix the tag's modbus address with a capital 'G' i.e. G401190 instead of 401190. I don't know if it is possible to use this mechanism combined with %MW notation.