Add support for byte strings in the device information fields (#693)

* Add support for byte strings in the device information fields
Iterate over the list of identity values and append the bytes if the field is a byte string, append the encoded string otherwise.

* Review comments, isinstance instead of 'type is'

Co-authored-by: Sytse Reitsma <[email protected]>

Author: sytsereitsma

pymodbus/other_message.py

@@ -369,7 +369,16 @@ def execute(self, context=None):
             reportSlaveIdData = getattr(context, 'reportSlaveIdData', None)
         if not reportSlaveIdData:
             information = DeviceInformationFactory.get(_MCB)
-            identifier = "-".join(information.values()).encode()
+
+            # Support identity values as bytes data and regular str data
+            id_data = []
+            for v in information.values():
+                if isinstance(v, bytes):
+                    id_data.append(v)
+                else:
+                    id_data.append(v.encode())
+
+            identifier = b"-".join(id_data)
             identifier = identifier or b'Pymodbus'
             reportSlaveIdData = identifier
         return ReportSlaveIdResponse(reportSlaveIdData)

test/test_other_messages.py

@@ -87,6 +87,45 @@ def testGetCommEventLogWithEvents(self):
         self.assertEqual(response.event_count, 0x12)
         self.assertEqual(response.events, [0x12,0x34,0x56])
 
+    def testReportSlaveIdRequest(self):
+        with mock.patch("pymodbus.other_message.DeviceInformationFactory") as dif:
+            # First test regular identity strings
+            identity = {
+                0x00: 'VN',  # VendorName
+                0x01: 'PC',  # ProductCode
+                0x02: 'REV',  # MajorMinorRevision
+                0x03: 'VU',  # VendorUrl
+                0x04: 'PN',  # ProductName
+                0x05: 'MN',  # ModelName
+                0x06: 'UAN',  # UserApplicationName
+                0x07: 'RA',  # reserved
+                0x08: 'RB',  # reserved
+            }
+            dif.get.return_value = identity
+            expected_identity = "-".join(identity.values()).encode()
+
+            request = ReportSlaveIdRequest()
+            response = request.execute()
+            self.assertEqual(response.identifier, expected_identity)
+
+            # Change to byte strings and test again (final result should be the same)
+            identity = {
+                0x00: b'VN',  # VendorName
+                0x01: b'PC',  # ProductCode
+                0x02: b'REV',  # MajorMinorRevision
+                0x03: b'VU',  # VendorUrl
+                0x04: b'PN',  # ProductName
+                0x05: b'MN',  # ModelName
+                0x06: b'UAN',  # UserApplicationName
+                0x07: b'RA',  # reserved
+                0x08: b'RB',  # reserved
+            }
+            dif.get.return_value = identity
+
+            request = ReportSlaveIdRequest()
+            response = request.execute()
+            self.assertEqual(response.identifier, expected_identity)
+
     def testReportSlaveId(self):
         with mock.patch("pymodbus.other_message.DeviceInformationFactory") as dif:
             dif.get.return_value = dict()