feat(s7commplus): complete subscription lifecycle

CHANGES.md

@@ -6,6 +6,14 @@ CHANGES
 
 Major release: new `s7commplus` package with S7CommPlus protocol support.
 
+* Correlate S7CommPlus responses by opcode, function, and sequence; preserve
+  interleaved notifications and serialize synchronous wire requests.
+* Verify authenticated V3 responses and cumulative fragment digests before
+  parsing, invalidating the connection with a dedicated integrity error on any
+  mismatch or truncated envelope.
+* Complete symbolic subscription lifecycle handling with catalog-tag decoding,
+  bounded sync/async delivery, overflow and sequence-gap diagnostics, finite
+  credit replenishment, and stale-generation filtering.
 * Decode corroborating CPU execution attributes so S7CommPlus `get_cpu_state()`
   distinguishes RUN from STOP on S7-1500 and returns UNKNOWN for absent or
   inconsistent state attributes, including S7-1200 responses that omit them.

README.rst

@@ -128,22 +128,32 @@ PUT/GET enabled.
               print(result.tag.name, result.value)
           else:
               print(result.tag.name, result.error)
-* **Symbolic data subscriptions** -- monitor values using access sequences
-  returned by ``browse()``::
+* **Symbolic data subscriptions** -- monitor catalog tags or access sequences
+  through bounded sync/async notification streams::
 
       from s7commplus import Client
 
       client = Client()
-      client.connect("192.168.1.10", 0, 1, password="secret")
-      subscription_id = client.create_subscription(["8A0E0007.A"], cycle_ms=100)
-      notification = client.receive_subscription_notification()
-      value = notification.values[1]
+      client.connect("192.168.1.10", password="secret")
+      tag = client.resolve_tag("DB1.Motor.Speed")
+      subscription_id = client.create_subscription([tag], cycle_ms=100)
+      notification = client.receive_subscription_notification(subscription_id)
+      value = notification.decoded_values[1]
+      raw_value = notification.values[1]
       client.delete_subscription(subscription_id)
       client.disconnect()
 
-  Reference IDs default to the one-based position of each access sequence.
-  Subscriptions use symbolic LIDs and therefore cannot be created from raw DB
-  byte offsets.
+  ``iter_subscription_notifications()`` provides a bounded synchronous
+  iterator; the async client provides an async iterator and
+  ``subscription_queue()``. Finite notification credits are replenished
+  automatically. ``subscription_diagnostics()`` reports queue overflow and
+  sequence gaps. Reference IDs default to the one-based item position. Raw
+  values remain available when a datatype is unknown or structured.
+
+  Deleting or disconnecting invalidates the local subscription state. Automatic
+  reconnect does not silently recreate subscriptions: create them again so the
+  caller can decide how to handle any update gap. Subscriptions use symbolic
+  LIDs and cannot be created from raw DB byte offsets.
 * **TIA Portal XML import** -- import symbol tables from TIA Portal exports
 
 **Help us test!** If you have access to any Siemens S7 PLC, we would greatly

s7commplus/__init__.py

@@ -13,6 +13,7 @@
     data = client.db_read(1, 0, 4)
 """
 
+from .async_client import AsyncSubscriptionQueue
 from .async_client import S7CommPlusAsyncClient as AsyncClient
 from .alarm import Alarm, AlarmNotification, AlarmText, LanguageId
 from .blob_decompressor import decompress_blob, find_and_decompress
@@ -22,7 +23,7 @@
 from .connection import S7CommPlusConnection
 from .server import CPUState, DataBlock
 from .server import S7CommPlusServer as Server
-from .subscription import SubscriptionItem, SubscriptionNotification
+from .subscription import SubscriptionDiagnostics, SubscriptionItem, SubscriptionNotification
 from .tag_browser import (
     DataBlock as ExploreDataBlock,
 )
@@ -40,6 +41,7 @@
     "AlarmText",
     "ArrayDimension",
     "AsyncClient",
+    "AsyncSubscriptionQueue",
     "CPUState",
     "Client",
     "DBWriteItem",
@@ -51,6 +53,7 @@
     "Server",
     "SubscriptionItem",
     "SubscriptionNotification",
+    "SubscriptionDiagnostics",
     "SymbolCatalog",
     "SymbolicReadItem",
     "SymbolicTag",