Add isError() method to Modbus exceptions (refer #298), updated changelogs, bumped version to 1.5.1

Author: dhoomakethu

CHANGELOG.rst

@@ -1,3 +1,21 @@
+Version 1.5.1
+------------------------------------------------------------
+* Fix device information selectors
+* Fixed behaviour of the MEI device information command as a server when an invalid object_id is provided by an external client.
+* Add support for repeated MEI device information Object IDs (client/server)
+* Added support for encoding device information when it requires more than one PDU to pack.
+* Added REPR statements for all syncchronous clients
+* Added `isError` method to exceptions, Any response received can be tested for success before proceeding.
+
+    ```
+    res = client.read_holding_registers(...)
+    if not res.isError():
+        # proceed
+    else:
+        # handle error or raise
+    ```
+* Add examples for MEI read device information request
+
 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

pymodbus/exceptions.py

@@ -18,6 +18,10 @@ def __init__(self, string):
     def __str__(self):
         return 'Modbus Error: %s' % self.string
 
+    def isError(self):
+        """Error"""
+        return True
+
 
 class ModbusIOException(ModbusException):
     ''' Error resulting from data i/o '''

pymodbus/pdu.py

@@ -129,6 +129,7 @@ def __init__(self, **kwargs):
         ModbusPDU.__init__(self, **kwargs)
 
     def isError(self):
+        """Checks if the error is a success or failure"""
         return self.function_code > 0x80
 
 

pymodbus/version.py

@@ -41,7 +41,7 @@ def __str__(self):
         return '[%s, version %s]' % (self.package, self.short())
 
 
-version = Version('pymodbus', 1, 5, 0)
+version = Version('pymodbus', 1, 5, 1)
 
 
 version.__name__ = 'pymodbus'  # fix epydoc error