Add retries to ModbusPDU class (#2672)

Author: mdeneen

pymodbus/pdu/pdu.py

@@ -38,6 +38,7 @@ def __init__(self,
         self.status: int = status
         self.exception_code: int = 0
         self.fut: asyncio.Future
+        self.retries: int = 0
 
     def isError(self) -> bool:
         """Check if the error is a success or failure."""
@@ -67,7 +68,8 @@ def __str__(self) -> str:
             f"count={self.count}, "
             f"bits={self.bits!s}, "
             f"registers={self.registers!s}, "
-            f"status={self.status!s})"
+            f"status={self.status!s}"
+            f"retries={self.retries})"
         )
 
     def get_response_pdu_size(self) -> int:

pymodbus/transaction/transaction.py

@@ -129,7 +129,9 @@ def sync_execute(self, no_response_expected: bool, request: ModbusPDU) -> Modbus
                 if no_response_expected:
                     return ExceptionResponse(0xff)
                 try:
-                    return self.sync_get_response(request.dev_id, request.transaction_id)
+                    response = self.sync_get_response(request.dev_id, request.transaction_id)
+                    response.retries = count_retries
+                    return response
                 except asyncio.exceptions.TimeoutError:
                     count_retries += 1
             if self.count_until_disconnect < 0:
@@ -170,6 +172,7 @@ async def execute(self, no_response_expected: bool, request: ModbusPDU) -> Modbu
                         raise ModbusIOException(
                             f"ERROR: request ask for id={request.dev_id} but got id={response.dev_id}, CLOSING CONNECTION."
                         )
+                    response.retries = count_retries
                     return response
                 except asyncio.exceptions.TimeoutError:
                     count_retries += 1