pdo: fix index access via CiA 301 parameter record indices

canopen/pdo/base.py

@@ -40,23 +40,32 @@ def __iter__(self):
         return iter(self.map)
 
     def __getitem__(self, key: Union[int, str]):
-        if isinstance(key, int):
-            if key == 0:
-                raise KeyError("PDO index zero requested for 1-based sequence")
-            if (
-                0 < key <= 512  # By PDO Index
-                or 0x1600 <= key <= 0x17FF  # By RPDO ID (512)
-                or 0x1A00 <= key <= 0x1BFF  # By TPDO ID (512)
-            ):
-                return self.map[key]
-        for pdo_map in self.map.values():
-            try:
-                return pdo_map[key]
-            except KeyError:
-                # ignore if one specific PDO does not have the key and try the next one
-                continue
+    if isinstance(key, int):
+        if key == 0:
+            raise KeyError("PDO index zero requested for 1-based sequence")
+        if 0 < key <= 512:
+            # Sequential 1-based index, direct lookup
+            return self.map[key]
+        elif 0x1400 <= key <= 0x15FF:
+            # RPDO communication parameter records (CiA 301)
+            return self.map[(key - 0x1400) + 1]
+        elif 0x1600 <= key <= 0x17FF:
+            # RPDO mapping parameter records (CiA 301)
+            return self.map[(key - 0x1600) + 1]
+        elif 0x1800 <= key <= 0x19FF:
+            # TPDO communication parameter records (CiA 301)
+            return self.map[(key - 0x1800) + 1]
+        elif 0x1A00 <= key <= 0x1BFF:
+            # TPDO mapping parameter records (CiA 301)
+            return self.map[(key - 0x1A00) + 1]
         raise KeyError(f"PDO: {key} was not found in any map")
-
+    for pdo_map in self.map.values():
+        try:
+            return pdo_map[key]
+        except KeyError:
+            continue
+    raise KeyError(f"PDO: {key} was not found in any map")
+
     def __len__(self):
         return len(self.map)
 

test/test_pdo.py

@@ -38,8 +38,18 @@ def test_pdo_map_getitem(self):
         self.assertEqual(pdo['INTEGER32 value'].raw, 0x01020304)
         self.assertEqual(pdo['BOOLEAN value'].raw, False)
         self.assertEqual(pdo['BOOLEAN value 2'].raw, True)
-
-    def test_pdo_getitem(self):
+def test_pdo_access_by_index(network):
+    node = network[1]
+    # Should work by sequential index
+    assert node.rpdo[1] is not None
+    # Should also work by CiA 301 mapping record index
+    assert node.rpdo[0x1600] is node.rpdo[1]
+    # And by communication record index (the flaw in PR #613)
+    assert node.rpdo[0x1400] is node.rpdo[1]
+    # Same for TPDO
+    assert node.tpdo[0x1A00] is node.tpdo[1]
+    assert node.tpdo[0x1800] is node.tpdo[1]
+        def test_pdo_getitem(self):
         node = self.node
         self.assertEqual(node.tpdo[1]['INTEGER16 value'].raw, -3)
         self.assertEqual(node.tpdo[1]['UNSIGNED8 value'].raw, 0xf)