Questions engineers ask before trusting a new tool.

Yes. The community edition is distributed under GPL-3.0-or-later and does not require an account or license key. The source and release packages are public.

SCL is not required for the first live MMS inspection. ARSAS can discover the complete typed model from an approved endpoint. After successful full discovery, it can generate an Edition 2 IID or Edition 1 ICD with companion JSON and Markdown evidence. A selected live RCB can also become a bounded Edition 1 or Edition 2 CID baseline.

The desktop application does not require a cloud account. Network access is still required to reach the approved IED. Update, release and issue links require internet access.

The current public Windows binaries are not Authenticode-signed. Verify the exact SHA-256 published in the Download Center before use. The warning is not hidden or presented as proof of malware.

The IEC 61850 feature scope is the same. Installer provides Windows registration, Start menu and uninstall behavior. Portable ZIP runs from an approved writable folder and is updated by replacing the package.

Npcap is required for raw-Ethernet GOOSE and Sampled Values capture. Ordinary MMS association, model discovery, reads, reporting, SCL generation and file-service workflows do not inherently require Npcap.

No universal vendor claim is made. Generated SCL is vendor-neutral, typed and schema-aware, but compatibility is service-specific and proprietary importers may add rules beyond the standard. Validate every receiving system.

Existing configuration and read-only evidence are preferred. Specific recovery workflows may use writes only where supported, enabled and authorized. A successful write is not proof that the project configuration is correct.

Guarded Direct and Select-Before-Operate workflows exist. Active control requires an approved procedure, plant authority, correct interlocks and independent safety checks. Never use a software button as the sole authorization.

No software alone can declare an operational network safe. Use ARSAS only inside an approved laboratory, FAT, SAT or commissioning boundary with controlled routing, permissions and recovery procedures.

Optional aggregate analytics are denied by default and require consent. Relay addresses, SCL files, signal values and project data are not collected by the website. The desktop application has no website analytics dependency.

Use the structured GitHub issue form. Include ARSAS version, Windows version, device identity when disclosure is permitted, firmware, service scope, exact sanitized diagnostics, reproduction steps and confirmation that credentials and confidential project data were removed.