| HTTP Status | Meaning | Solution | | :--- | :--- | :--- | | 401 Unauthorized | Authentication failed. | Check username/password. User must have WinCC remote roles. | | 403 Forbidden | Authenticated but not authorized. | Assign "WinCC Remote Read" permission. | | 404 Not Found | Tag or endpoint doesn’t exist. | Verify tag name spelling (case-sensitive). Check if tag is released for Web access. | | 500 Internal Error | WinCC runtime issue. | Check WinCC event log. Runtime might be busy. | | 503 Service Unavailable | REST API service not started. | Ensure "Enable REST API" is checked and runtime is running. |
: Uses standard HTTP methods (GET, POST, etc.) and returns data in JSON format.
When using the WinCC REST API, it's essential to consider security aspects, such as:
to bridge the gap between industrial automation (OT) and IT systems. It allows external applications—like ERPs, MES, or mobile apps—to read and write SCADA data using standard web protocols like HTTP/HTTPS and JSON. www.siemens.com Two-Way Communication in WinCC V8
: Access details from the tag management system.
| HTTP Status | Meaning | Solution | | :--- | :--- | :--- | | 401 Unauthorized | Authentication failed. | Check username/password. User must have WinCC remote roles. | | 403 Forbidden | Authenticated but not authorized. | Assign "WinCC Remote Read" permission. | | 404 Not Found | Tag or endpoint doesn’t exist. | Verify tag name spelling (case-sensitive). Check if tag is released for Web access. | | 500 Internal Error | WinCC runtime issue. | Check WinCC event log. Runtime might be busy. | | 503 Service Unavailable | REST API service not started. | Ensure "Enable REST API" is checked and runtime is running. |
: Uses standard HTTP methods (GET, POST, etc.) and returns data in JSON format.
When using the WinCC REST API, it's essential to consider security aspects, such as:
to bridge the gap between industrial automation (OT) and IT systems. It allows external applications—like ERPs, MES, or mobile apps—to read and write SCADA data using standard web protocols like HTTP/HTTPS and JSON. www.siemens.com Two-Way Communication in WinCC V8
: Access details from the tag management system.
