Minor improvements

* Add support for using dot (.) to address sub-index elements in the OD
* Make SdoVariable awaitable for fetching
* Fix SdoClient.aabort() that were missing

Author: sveinse

canopen/objectdictionary/__init__.py

@@ -108,6 +108,9 @@ def __getitem__(
         """Get object from object dictionary by name or index."""
         item = self.names.get(index) or self.indices.get(index)
         if item is None:
+            if isinstance(index, str) and '.' in index:
+                parts = index.split('.')
+                return self[parts[0]][".".join(parts[1:])]
             name = "0x%X" % index if isinstance(index, int) else index
             raise KeyError("%s was not found in Object Dictionary" % name)
         return item

canopen/sdo/base.py

@@ -168,6 +168,9 @@ def __init__(self, sdo_node: SdoBase, od: ObjectDictionary):
         self.sdo_node = sdo_node
         variable.Variable.__init__(self, od)
 
+    def __await__(self):
+        return self.aget_raw().__await__()
+
     def get_data(self) -> bytes:
         return self.sdo_node.upload(self.od.index, self.od.subindex)
 

canopen/sdo/client.py

@@ -151,7 +151,7 @@ async def arequest_response(self, sdo_request):
             except SdoCommunicationError as e:
                 retries_left -= 1
                 if not retries_left:
-                    self.abort(0x5040000)
+                    await self.aabort(0x5040000)
                     raise
                 logger.warning(str(e))
 
@@ -164,6 +164,15 @@ def abort(self, abort_code=0x08000000):
         self.send_request(request)
         logger.error("Transfer aborted by client with code 0x{:08X}".format(abort_code))
 
+    async def aabort(self, abort_code=0x08000000):
+        """Abort current transfer."""
+        request = bytearray(8)
+        request[0] = REQUEST_ABORTED
+        # TODO: Is it necessary to include index and subindex?
+        struct.pack_into("<L", request, 4, abort_code)
+        await self.asend_request(request)
+        logger.error("Transfer aborted by client with code 0x{:08X}".format(abort_code))
+
     @ensure_not_async  # NOTE: Safeguard for accidental async use
     def upload(self, index: int, subindex: int) -> bytes:
         """May be called to make a read operation without an Object Dictionary.