A native OPC UA alarm source's SourceReference has to be two things at once:
it is parsed as a NodeId to open the monitored item, and matched as a plain-name
prefix against the event's SourceName to route the transition to an instance. No
string is both, so a NodeId-form binding subscribed correctly and then silently
dropped every transition — "pymodbus/plc/HR200".StartsWith("nsu=...;s=pymodbus/plc/HR200")
is false. Only the empty (Server-object) binding worked, because StartsWith("")
matches everything, which is why the sole live smoke test never caught it.
Each OPC UA alarm feed is opened for exactly one binding, so every transition on
it belongs to that binding. The adapter now tags each transition's routing
identity (SourceObjectReference) with the binding string verbatim via the pure
OpcUaAlarmMapper.BuildIdentity, making DataConnectionActor's routing key an exact
match regardless of whether the binding is stored as ns=<index> or the durable
nsu=<uri> form. The Server-object aggregate feed keeps an empty routing identity,
so it reaches only "mirror everything" subscribers and never leaks into a
specific-node binding. The per-condition SourceReference key stays the readable
SourceName.ConditionName, so persistence and display are unchanged, and MxGateway
is untouched — its bindings are names and its mapper already emits matching names.
Unblocked by lmxopcua#473 (OtOpcUa now populates SourceNode/SourceName/EventType
on conditions); SourceName is the RawPath, so the per-condition key is unique.
Live end-to-end verification against native alarms still needs a v3 rig.
Fixes: Gitea #17
A stored ns=<index> reference is only meaningful against one server's namespace
table. A server that adds, removes or reorders a namespace silently re-points
every binding: best case BadNodeIdUnknown, worst case the index now names a
different namespace holding a colliding identifier and the binding resolves to
the wrong node with Good quality. Nothing could detect that, because ScadaBridge
stored no namespace URI anywhere.
OtOpcUa v3.0 makes this concrete: v2's sole custom namespace and v3's raw
namespace both sit at index 2, so v2-era bindings resolve against v3 without
error while meaning something else entirely.
Adds OpcUaNodeReference as the single translation seam between stored references
and the wire. Resolve() accepts both ns=<index>;s=<id> (existing bindings, which
keep working unchanged) and the durable nsu=<uri>;s=<id>, mapping the URI to the
live index at use time; it is wired into every parse site — subscribe, read,
write, alarm-subscribe and browse. An unpublished URI now throws naming the URI
rather than binding to whatever occupies that index, and a svr= reference to
another server is rejected instead of being resolved against the wrong address
space.
The browser emits ToDurable(), so what the picker shows is what gets stored and
newly-authored bindings are index-proof from the start. That also closes a
round-trip gap: browse previously emitted ExpandedNodeId.ToString(), which for a
URI- or server-index-carrying reference produced a string NodeId.Parse could not
read back — the same method already resolved it correctly 57 lines later.
Bindings stored before this change keep their ns= form and keep working; they are
only as durable as the server's namespace order. Re-authoring against the picker
is what makes them durable, and that re-bind still needs a live v3 rig.
Refs: Gitea #14
Joseph Doherty