Update datastore remote to handle write requests (#1166)

* Update datastore remote to handle write requests.

Author: janiversen

examples/modbus_forwarder.py

@@ -1,11 +1,15 @@
 #!/usr/bin/env python3
 """Pymodbus synchronous forwarder.
 
-This is a repeater or converter and  an example of just how powerful datastore is.
+This is a repeater or converter and an example of just how powerful datastore is.
 
-It consist of a server (any comm) and a client (any comm) and basically all request
-received by the server is sent by client and all responses received by the
-client is sent back by the server.
+It consist of a server (any comm) and a client (any comm), functionality:
+
+a) server receives a read/write request from external client:
+
+    - client sends a new read/write request to target server
+    - client receives response and updates the datastore
+    - server sends new response to external client
 
 Both server and client are tcp based, but it can be easily modified to any server/client
 (see client_sync.py and server_sync.py for other communication types)
@@ -69,5 +73,7 @@ async def run_forwarder(args):
             )
         ],
     )
+    cmd_args.port = 5021
+    cmd_args.client_port = 5020
     run_args = setup_forwarder(cmd_args)
     asyncio.run(run_forwarder(run_args))

pymodbus/datastore/remote.py

@@ -49,11 +49,18 @@ def validate(self, fc_as_hex, address, count=1):
         """
         txt = f"validate[{fc_as_hex}] {address}:{count}"
         _logger.debug(txt)
-        self.result = self.__get_callbacks[self.decode(fc_as_hex)](address, count)
+        group_fx = self.decode(fc_as_hex)
+        if fc_as_hex in self._write_fc:
+            func_fc = self.__set_callbacks[f"{group_fx}{fc_as_hex}"]
+        else:
+            func_fc = self.__get_callbacks[group_fx]
+        self.result = func_fc(address, count)
         return not self.result.isError()
 
     def getValues(self, fc_as_hex, address, count=1):
         """Get values from real call in validate"""
+        if fc_as_hex in self._write_fc:
+            return [0]
         return self.__extract_result(self.decode(fc_as_hex), self.result)
 
     def setValues(self, fc_as_hex, address, values):
@@ -89,19 +96,32 @@ def __build_mapping(self):
             ),
         }
         self.__set_callbacks = {
-            "d": lambda a, v: self._client.write_coils(  # pylint: disable=unnecessary-lambda
+            "d5": lambda a, v: self._client.write_coil(  # pylint: disable=unnecessary-lambda
+                a, v, **kwargs
+            ),
+            "d15": lambda a, v: self._client.write_coils(  # pylint: disable=unnecessary-lambda
+                a, v, **kwargs
+            ),
+            "c5": lambda a, v: self._client.write_coils(  # pylint: disable=unnecessary-lambda
+                a, v, **kwargs
+            ),
+            "c15": lambda a, v: self._client.write_coils(  # pylint: disable=unnecessary-lambda
+                a, v, **kwargs
+            ),
+            "h6": lambda a, v: self._client.write_register(  # pylint: disable=unnecessary-lambda
                 a, v, **kwargs
             ),
-            "c": lambda a, v: self._client.write_coils(  # pylint: disable=unnecessary-lambda
+            "h16": lambda a, v: self._client.write_registers(  # pylint: disable=unnecessary-lambda
                 a, v, **kwargs
             ),
-            "h": lambda a, v: self._client.write_registers(  # pylint: disable=unnecessary-lambda
+            "i6": lambda a, v: self._client.write_register(  # pylint: disable=unnecessary-lambda
                 a, v, **kwargs
             ),
-            "i": lambda a, v: self._client.write_registers(  # pylint: disable=unnecessary-lambda
+            "i16": lambda a, v: self._client.write_registers(  # pylint: disable=unnecessary-lambda
                 a, v, **kwargs
             ),
         }
+        self._write_fc = (0x05, 0x06, 0x15, 0x16, 0x17)
 
     def __extract_result(self, fc_as_hex, result):
         """Extract the values out of a response.

test/test_examples.py

@@ -12,7 +12,9 @@
 from examples.client_calls import run_async_calls, run_sync_calls
 from examples.client_payload import run_binary_payload_client
 from examples.client_sync import run_sync_client, setup_sync_client
-from examples.modbus_forwarder import run_forwarder, setup_forwarder
+from examples.modbus_forwarder import setup_forwarder
+
+# from examples.modbus_forwarder import run_forwarder, setup_forwarder
 from examples.server_async import run_async_server, setup_server
 from examples.server_payload import run_payload_server
 from examples.server_sync import run_sync_server
@@ -171,16 +173,16 @@ async def test_exp_forwarder(  # pylint: disable=unused-argument
     """Test modbus forwarder."""
     if pytest.IS_WINDOWS:
         return
-    return
 
-    pymodbus_apply_logging_config()  # pylint: disable=unreachable
+    pymodbus_apply_logging_config()
     cmd_args = Commandline
     cmd_args.comm = test_comm
     cmd_args.framer = test_framer
     cmd_args.port = test_port + test_port_offset + 1
     cmd_args.client_port = test_port + test_port_offset
     run_args = setup_forwarder(cmd_args)
-    task = asyncio.create_task(run_forwarder(run_args))
+    # task = asyncio.create_task(run_forwarder(run_args))
+    task = asyncio.create_task(run_async_server(run_args))
     await asyncio.sleep(0.1)
 
     real_client = AsyncModbusTcpClient(host="127.0.0.1", port=cmd_args.port)
@@ -191,6 +193,16 @@ async def test_exp_forwarder(  # pylint: disable=unused-argument
     assert check_client.connected
     await asyncio.sleep(0.1)
 
+    # rr = _check_call(client.read_holding_registers(1, 1, slave=SLAVE))
+    # rr = _check_call(client.read_coils(1, 1, slave=SLAVE))
+    # rr = _check_call(client.read_discrete_inputs(0, 8, slave=SLAVE))
+    # rr = _check_call(client.read_input_registers(1, 8, slave=SLAVE))
+    # --
+    # rr = _check_call(client.write_register(1, 10, slave=SLAVE))
+    # rr = _check_call(client.write_coil(0, True, slave=SLAVE))
+    # rr =_check_call(client.write_registers(1, [10] * 8, slave=SLAVE))
+    # rr = _check_call(client.write_coils(1, [True] * 21, slave=SLAVE))
+
     # Verify read values are identical
     # rr_real = await real_client.read_holding_registers(1,1,slave=1)
     # assert rr_real.registers, f"---> {rr_real}"