Kaly,
Thank you for your question.
PLCnext can work as gRPC client as the PLCnext runtime has an internal gRPC server to allow access of variables from the PLC GDS (Global data space) via gRPC.
An example using a Python script can be found here: Using gRPC communication So in your instance I would be tempted to say you could create a python script running on the controller to pass data between the Robot and the PLC. However we would need to know more about the application and the products involved before we could provide a more engineered solution.
If you are uncomfortable sharing further details on a public forum. Feel free to send an email with further details to access local technical support - uk-info@phoenixcontact.co.uk
Regards,
Andy