Just to clarify — you mentioned PCS 7 version 9.0 SP5 (V9.0.5).

However, as per official Siemens releases, the latest officially available version for PCS 7 V9.0 is SP3 (i.e., V9.0 SP3 / 9.0.3).

1. Siemens Support Documentation

Siemens offers comprehensive manuals and technical documents for PCS 7 and TIA Portal integration. These documents cover the steps required to export a PCS 7 project and import it into TIA Portal using device proxies. You can access the technical documentation for SIMATIC PCS 7 V9.1 software here:​R

Note: While this documentation is for V9.1, the procedures are largely applicable to V9.0 SP5 as well.

2. Step-by-Step Guide for Initializing Device Proxy

For a detailed guide on initializing a device proxy via a project file, refer to the following Siemens support page:​

This guide provides instructions on how to create and initialize device proxies, which is essential for integrating PCS 7 projects into TIA Portal.​
https://support.industry.siemens.com/cs/mk/en/view/109773506/94292276619

3. Community Discussions and Solutions

Engaging with the Siemens support forums can provide insights from other users who have faced similar challenges. For instance, discussions on proxy and IO devices in TIA 15.1 can be found here:

These forums often contain practical solutions and workarounds shared by experienced professionals.