Simplify syncTransactionManager. (#2443)

pymodbus/client/tcp.py

@@ -241,14 +241,16 @@ def recv(self, size: int | None) -> bytes:
             time_ = time.time()
 
             # If size isn't specified continue to read until timeout expires.
-            if size:
-                recv_size = size - data_length
-
+            if not size:
+                break
             # Timeout is reduced also if some data has been received in order
             # to avoid infinite loops when there isn't an expected response
             # size and the slave sends noisy data continuously.
             if time_ > end:
                 break
+
+            recv_size = size - data_length
+
         self.last_frame_end = round(time.time(), 6)
         return b"".join(data)
 

pymodbus/client/udp.py

@@ -206,7 +206,7 @@ def recv(self, size: int | None) -> bytes:
         if not self.socket:
             raise ConnectionException(str(self))
         if size is None:
-            size = 0
+            size = 4096
         data = self.socket.recvfrom(size)[0]
         self.last_frame_end = round(time.time(), 6)
         return data

pymodbus/framer/tls.py

@@ -8,10 +8,16 @@ class FramerTLS(FramerBase):
     """Modbus TLS frame type.
 
     Layout::
-      [ Function Code] [ Data ]
-        1b               Nb
+
+        [         MBAP Header         ] [ Function Code] [ Data ]
+        [ tid ][ pid ][ length ][ uid ]
+          2b     2b     2b        1b           1b           Nb
+
+    length = uid + function code + data
     """
 
+    MIN_SIZE = 8
+
     def decode(self, data: bytes) -> tuple[int, int, int, bytes]:
         """Decode MDAP+PDU."""
         tid = int.from_bytes(data[0:2], 'big')