Modbus sync client timing enhancements #221

 Fix TCP server #256, #260

Author: dhoomakethu

CHANGELOG.rst

@@ -1,3 +1,13 @@
+Version 1.5.0
+------------------------------------------------------------
+* Improve transaction speeds for sync clients (RTU/ASCII), now retry on empty happens only when retry_on_empty kwarg is passed to client during intialization
+
+`client = Client(..., retry_on_empty=True)`
+
+* Fix tcp servers (sync/async) not processing requests with transaction id > 255
+* Introduce new api to check if the received response is an error or not (response.isError())
+* Fix Misc examples
+
 Version 1.4.0
 ------------------------------------------------------------
 * Bug fix Modbus TCP client reading incomplete data

examples/common/synchronous_server.py

@@ -19,15 +19,19 @@
 from pymodbus.datastore import ModbusSequentialDataBlock
 from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
 
-from pymodbus.transaction import ModbusRtuFramer
+from pymodbus.transaction import ModbusRtuFramer, ModbusBinaryFramer
 # --------------------------------------------------------------------------- # 
 # configure the service logging
 # --------------------------------------------------------------------------- # 
 import logging
-logging.basicConfig()
+FORMAT = '%(asctime)-15s %(levelname)-8s %(module)-8s:%(lineno)-8s %(message)s'
+logging.basicConfig(format=FORMAT)
 log = logging.getLogger()
 log.setLevel(logging.DEBUG)
 
+SERIAL_PORT = "/tmp/ptyp0"
+TCP_PORT = 5020
+
 
 def run_server():
     # ----------------------------------------------------------------------- # 
@@ -85,11 +89,11 @@ def run_server():
     #     store = ModbusSlaveContext(..., zero_mode=True)
     # ----------------------------------------------------------------------- # 
     store = ModbusSlaveContext(
-        di = ModbusSequentialDataBlock(0, [17]*100),
-        co = ModbusSequentialDataBlock(0, [17]*100),
-        hr = ModbusSequentialDataBlock(0, [17]*100),
-        ir = ModbusSequentialDataBlock(0, [17]*100))
-    context = ModbusServerContext(slaves=store, single=True)
+        di=ModbusSequentialDataBlock(0, [17]*100),
+        co=ModbusSequentialDataBlock(0, [17]*100),
+        hr=ModbusSequentialDataBlock(0, [17]*100),
+        ir=ModbusSequentialDataBlock(0, [17]*100))
+    context = ModbusServerContext(slaves={1: store, 2: store}, single=False)
 
     # ----------------------------------------------------------------------- # 
     # initialize the server information
@@ -108,18 +112,23 @@ def run_server():
     # run the server you want
     # ----------------------------------------------------------------------- # 
     # Tcp:
-    StartTcpServer(context, identity=identity, address=("localhost", 5020))
+    StartTcpServer(context, identity=identity, address=("localhost", TCP_PORT))
 
     # Udp:
-    # StartUdpServer(context, identity=identity, address=("localhost", 502))
+    # StartUdpServer(context, identity=identity,
+    #                address=("localhost", TCP_PORT))
 
     # Ascii:
-    #  StartSerialServer(context, identity=identity,
-    #                    port='/dev/pts/3', timeout=1)
-    
+    # StartSerialServer(context, identity=identity,
+    #                    port=SERIAL_PORT, timeout=1)
+
+    # Binary:
+    # StartSerialServer(context, identity=identity, framer=ModbusBinaryFramer,
+    #                    port=SERIAL_PORT, timeout=1)
+
     # RTU:
     # StartSerialServer(context, framer=ModbusRtuFramer, identity=identity,
-    #                   port='/dev/ptyp0', timeout=.005, baudrate=9600)
+    #                   port=SERIAL_PORT, timeout=.005, baudrate=9600)
 
 
 if __name__ == "__main__":

pymodbus/client/common.py

@@ -15,6 +15,19 @@
 from pymodbus.other_message import *
 
 
+class ModbusTransactionState(object):
+    """
+    Modbus Client States
+    """
+    IDLE = 0
+    SENDING = 1
+    WAITING_FOR_REPLY = 2
+    WAITING_TURNAROUND_DELAY = 3
+    PROCESSING_REPLY = 4
+    PROCESSING_ERROR = 5
+    TRANSCATION_COMPLETE = 6
+
+
 class ModbusClientMixin(object):
     '''
     This is a modbus client mixin that provides additional factory