SuiteLink Client

Cross-platform .NET 10 C# client for AVEVA SuiteLink tag operations.

Scope

Current implementation targets the normal SuiteLink tag protocol and supports:

• startup handshake and connect message encoding
• subscribe and unadvise flows
• update decoding for bool, int32, float32, and string
• write (POKE) encoding for bool, int32, float32, and string
• background receive loop for subscription updates without manual polling
• automatic reconnect with durable subscription replay after runtime disconnects
• best-effort latest-value catch-up replay after reconnect when enabled
• policy-based reconnect retry timing with exponential backoff and jitter support
• client/session/transport layers suitable for macOS, Linux, and Windows

Unsupported

This repository does not currently support:

• AlarmMgr / alarms and events
• secure SuiteLink V3 / TLS transport
• write queuing while reconnecting
• full outage-history replay of every missed value
• validated reconnect behavior against a live AVEVA server deployment
• validated support for richer System Platform data types such as double, int64, or DateTime

Build

dotnet build /Users/dohertj2/Desktop/suitelinkclient/SuiteLink.Client.slnx -c Release

Test

Unit tests:

dotnet test /Users/dohertj2/Desktop/suitelinkclient/SuiteLink.Client.slnx -v minimal

Focused protocol tests:

dotnet test /Users/dohertj2/Desktop/suitelinkclient/SuiteLink.Client.slnx --filter Protocol -v minimal

Integration

Live integration tests are safe by default and only run when explicitly enabled with environment variables.

See README.md for:

• required environment variables
• tag configuration
• enabling live round-trip tests for bool, int, float, and string

Notes

• The repository includes fixture-backed protocol tests under Fixtures.
• Protocol assumptions derived from reverse engineering are intentionally isolated in codec classes and tests so they can be refined against live captures later.
• Normal subscription use does not require calling ProcessIncomingAsync; the runtime loop dispatches updates in the background.
• After a runtime disconnect, the client enters Reconnecting, rebuilds the transport/session startup sequence, replays durable subscriptions, and resumes dispatch without caller resubscription.
• Reconnect timing is driven by SuiteLinkRetryPolicy; the default policy retries immediately, then uses bounded exponential backoff with jitter.
• Catch-up replay is best-effort latest-value refresh only. It does not represent every value missed during the outage window.
• If the client is reconnecting after a runtime disconnect, WriteAsync fails fast until the session is ready again.
• Reconnect behavior is currently verified with fixture-backed and fake-transport tests; live AVEVA validation is still required, especially for mixed-mode deployments and server-specific timing.