fix calculated_length

test/telegram_tests/apci_test.py

@@ -310,7 +310,7 @@ def test_calculated_length(self):
         payload = MemoryExtendedWrite(
             address=0x123456, count=3, data=bytes([0xAA, 0xBB, 0xCC])
         )
-        assert payload.calculated_length() == 9
+        assert payload.calculated_length() == 8
 
     def test_from_knx(self):
         """Test the from_knx method."""
@@ -366,14 +366,14 @@ class TestMemoryExtendedWriteResponse:
     def test_calculated_length(self):
         """Test the test_calculated_length method."""
         payload = MemoryExtendedWriteResponse(return_code=0, address=0x123456)
-        assert payload.calculated_length() == 6
+        assert payload.calculated_length() == 5
 
     def test_calculated_lengt_with_confirmation_data(self):
         """Test the test_calculated_length method."""
         payload = MemoryExtendedWriteResponse(
             return_code=0, address=0x123456, confirmation_data=bytes([0xAA, 0xBB])
         )
-        assert payload.calculated_length() == 8
+        assert payload.calculated_length() == 7
 
     def test_from_knx(self):
         """Test the from_knx method."""
@@ -446,7 +446,7 @@ class TestMemoryExtendedRead:
     def test_calculated_length(self):
         """Test the test_calculated_length method."""
         payload = MemoryExtendedRead(address=0x123456, count=3)
-        assert payload.calculated_length() == 6
+        assert payload.calculated_length() == 5
 
     def test_from_knx(self):
         """Test the from_knx method."""
@@ -487,7 +487,7 @@ def test_calculated_length(self):
         payload = MemoryExtendedReadResponse(
             return_code=0, address=0x123456, data=bytes([0xAA, 0xBB, 0xCC])
         )
-        assert payload.calculated_length() == 9
+        assert payload.calculated_length() == 8
 
     def test_from_knx(self):
         """Test the from_knx method."""

xknx/telegram/apci.py

@@ -524,12 +524,12 @@ def __init__(self, address: int, data: bytes, count: int | None = None) -> None:
 
     def calculated_length(self) -> int:
         """Get length of APCI payload."""
-        return 6 + len(self.data)
+        return 5 + len(self.data)
 
     @classmethod
     def from_knx(cls, raw: bytes) -> MemoryExtendedWrite:
         """Parse/deserialize from KNX/IP raw data."""
-        size = len(raw) - 6
+        size = len(raw) - 5
 
         # inject [0x00] before 3 bytes address to enable unsigned int unpack
         count, address, data = struct.unpack(
@@ -579,7 +579,7 @@ def __init__(
 
     def calculated_length(self) -> int:
         """Get length of APCI payload."""
-        return 6 + len(self.confirmation_data)
+        return 5 + len(self.confirmation_data)
 
     @classmethod
     def from_knx(cls, raw: bytes) -> MemoryExtendedWriteResponse:
@@ -633,7 +633,7 @@ def __init__(self, count: int, address: int) -> None:
 
     def calculated_length(self) -> int:
         """Get length of APCI payload."""
-        return 6
+        return 5
 
     @classmethod
     def from_knx(cls, raw: bytes) -> MemoryExtendedRead:
@@ -682,7 +682,7 @@ def __init__(self, return_code: int, address: int, data: bytes = b"") -> None:
 
     def calculated_length(self) -> int:
         """Get length of APCI payload."""
-        return 6 + len(self.data)
+        return 5 + len(self.data)
 
     @classmethod
     def from_knx(cls, raw: bytes) -> MemoryExtendedReadResponse: