Mitsubishi A Series PLC Troubleshooting

I need an expert to troubleshoot communication failures on a Mitsubishi A series PLC within a Melsecnet11 network.

I've already:
- Checked network connections
- Restarted PLC and network devices
- Verified device configurations

Ideal skills and experience:
- In-depth knowledge of Mitsubishi A series PLCs
- Experience with Melsecnet11 networks
- Strong troubleshooting skills for communication issues

Please provide a detailed approach and estimated time to resolve the issue.