fix virtual channel name logic with library interpreter and DAQmx 24.5+ (#723)

* fix fallback implementation (used in older driver versions and gRPC) in some cases

Author: zhindes

CHANGELOG.md

@@ -29,6 +29,7 @@ All notable changes to this project will be documented in this file.
 
 * ### Resolved Issues
     * Fix PEP 660 builds by setting `build-system` to use `poetry-core`
+    * [579: nidaqmx does not generate numbered virtual channel names correctly](https://github.com/ni/nidaqmx-python/issues/579)
 
 * ### Major Changes
     * Removed the `docs` extra and converted it to a Poetry dependency group.

generated/nidaqmx/_base_interpreter.py

@@ -1168,6 +1168,10 @@ def get_write_attribute_uint32(self, task, attribute):
     def get_write_attribute_uint64(self, task, attribute):
         raise NotImplementedError
 
+    @abc.abstractmethod
+    def internal_get_last_created_chan(self):
+        raise NotImplementedError
+
     @abc.abstractmethod
     def is_task_done(self, task):
         raise NotImplementedError

generated/nidaqmx/_grpc_interpreter.py

@@ -3597,6 +3597,9 @@ def set_runtime_environment(
             self, environment, environment_version, reserved_1, reserved_2):
         raise NotImplementedError
 
+    def internal_get_last_created_chan(self):
+        raise NotImplementedError
+
 
 def _assign_numpy_array(numpy_array, grpc_array):
     """

generated/nidaqmx/_library_interpreter.py

@@ -4048,6 +4048,30 @@ def get_write_attribute_uint64(self, task, attribute):
         self.check_for_error(error_code)
         return value.value
 
+    def internal_get_last_created_chan(self):
+        cfunc = lib_importer.windll.DAQmxInternalGetLastCreatedChan
+        if cfunc.argtypes is None:
+            with cfunc.arglock:
+                if cfunc.argtypes is None:
+                    cfunc.argtypes = [
+                        ctypes.c_char_p, ctypes.c_uint]
+
+        temp_size = 0
+        while True:
+            value = ctypes.create_string_buffer(temp_size)
+            size_or_code = cfunc(
+                value, temp_size)
+            if is_string_buffer_too_small(size_or_code):
+                # Buffer size must have changed between calls; check again.
+                temp_size = 0
+            elif size_or_code > 0 and temp_size == 0:
+                # Buffer size obtained, use to retrieve data.
+                temp_size = size_or_code
+            else:
+                break
+        self.check_for_error(size_or_code)
+        return value.value.decode(lib_importer.encoding)
+
     def is_task_done(self, task):
         is_task_done = c_bool32()
 

generated/nidaqmx/task/collections/_ai_channel_collection.py

@@ -2,6 +2,7 @@
 
 import numpy
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._ai_channel import AIChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -45,18 +46,28 @@ def _create_chan(self, physical_channel, name_to_assign_to_channel=''):
 
             Specifies the newly created AIChannel object.
         """
-        if name_to_assign_to_channel:
-            num_channels = len(unflatten_channel_string(physical_channel))
-
-            if num_channels > 1:
-                name = '{}0:{}'.format(
-                    name_to_assign_to_channel, num_channels-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            if name_to_assign_to_channel:
+                num_channels = len(unflatten_channel_string(physical_channel))
+
+                if num_channels > 1:
+                    virtual_channel_name = '{}0:{}'.format(
+                        name_to_assign_to_channel, num_channels-1)
+                else:
+                    virtual_channel_name = name_to_assign_to_channel
             else:
-                name = name_to_assign_to_channel
-        else:
-            name = physical_channel
+                virtual_channel_name = physical_channel
 
-        return AIChannel(self._handle, name, self._interpreter)
+        return AIChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_ai_accel_4_wire_dc_voltage_chan(
             self, physical_channel, name_to_assign_to_channel="",

generated/nidaqmx/task/collections/_ao_channel_collection.py

@@ -1,5 +1,6 @@
 # Do not edit this file; it was automatically generated.
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._ao_channel import AOChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -31,18 +32,28 @@ def _create_chan(self, physical_channel, name_to_assign_to_channel=''):
             
             Specifies the newly created AOChannel object.
         """
-        if name_to_assign_to_channel:
-            num_channels = len(unflatten_channel_string(physical_channel))
-
-            if num_channels > 1:
-                name = '{}0:{}'.format(
-                    name_to_assign_to_channel, num_channels-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            if name_to_assign_to_channel:
+                num_channels = len(unflatten_channel_string(physical_channel))
+
+                if num_channels > 1:
+                    virtual_channel_name = '{}0:{}'.format(
+                        name_to_assign_to_channel, num_channels-1)
+                else:
+                    virtual_channel_name = name_to_assign_to_channel
             else:
-                name = name_to_assign_to_channel
-        else:
-            name = physical_channel
+                virtual_channel_name = physical_channel
 
-        return AOChannel(self._handle, name, self._interpreter)
+        return AOChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_ao_current_chan(
             self, physical_channel, name_to_assign_to_channel="", min_val=0.0,

generated/nidaqmx/task/collections/_ci_channel_collection.py

@@ -1,5 +1,6 @@
 # Do not edit this file; it was automatically generated.
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._ci_channel import CIChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -33,18 +34,28 @@ def _create_chan(self, counter, name_to_assign_to_channel=''):
             
             Specifies the newly created CIChannel object.
         """
-        if name_to_assign_to_channel:
-            num_counters = len(unflatten_channel_string(counter))
-
-            if num_counters > 1:
-                name = '{}0:{}'.format(
-                    name_to_assign_to_channel, num_counters-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            if name_to_assign_to_channel:
+                num_counters = len(unflatten_channel_string(counter))
+
+                if num_counters > 1:
+                    virtual_channel_name = '{}0:{}'.format(
+                        name_to_assign_to_channel, num_counters-1)
+                else:
+                    virtual_channel_name = name_to_assign_to_channel
             else:
-                name = name_to_assign_to_channel
-        else:
-            name = counter
+                virtual_channel_name = counter
 
-        return CIChannel(self._handle, name, self._interpreter)
+        return CIChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_ci_ang_encoder_chan(
             self, counter, name_to_assign_to_channel="",

generated/nidaqmx/task/collections/_co_channel_collection.py

@@ -1,5 +1,6 @@
 # Do not edit this file; it was automatically generated.
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._co_channel import COChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -31,18 +32,28 @@ def _create_chan(self, counter, name_to_assign_to_channel=''):
             
             Specifies the newly created COChannel object.
         """
-        if name_to_assign_to_channel:
-            num_counters = len(unflatten_channel_string(counter))
-
-            if num_counters > 1:
-                name = '{}0:{}'.format(
-                    name_to_assign_to_channel, num_counters-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            if name_to_assign_to_channel:
+                num_counters = len(unflatten_channel_string(counter))
+
+                if num_counters > 1:
+                    virtual_channel_name = '{}0:{}'.format(
+                        name_to_assign_to_channel, num_counters-1)
+                else:
+                    virtual_channel_name = name_to_assign_to_channel
             else:
-                name = name_to_assign_to_channel
-        else:
-            name = counter
+                virtual_channel_name = counter
 
-        return COChannel(self._handle, name, self._interpreter)
+        return COChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_co_pulse_chan_freq(
             self, counter, name_to_assign_to_channel="",

generated/nidaqmx/task/collections/_di_channel_collection.py

@@ -1,5 +1,6 @@
 # Do not edit this file; it was automatically generated.
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._di_channel import DIChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -34,25 +35,37 @@ def _create_chan(self, lines, line_grouping, name_to_assign_to_lines=''):
             
             Specifies the newly created DIChannel object.
         """
-        unflattened_lines = unflatten_channel_string(lines)
-        num_lines = len(unflattened_lines)
-        
-        if line_grouping == LineGrouping.CHAN_FOR_ALL_LINES:
-            if name_to_assign_to_lines or num_lines == 1:
-                name = lines
-            else:
-                name = unflattened_lines[0] + '...'
-        else:
-            if name_to_assign_to_lines:
-                if num_lines > 1:
-                    name = '{}0:{}'.format(
-                        name_to_assign_to_lines, num_lines-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            unflattened_lines = unflatten_channel_string(lines)
+            num_lines = len(unflattened_lines)
+            
+            if line_grouping == LineGrouping.CHAN_FOR_ALL_LINES:
+                if name_to_assign_to_lines:
+                    virtual_channel_name = name_to_assign_to_lines
+                elif num_lines == 1:
+                    virtual_channel_name = lines
                 else:
-                    name = name_to_assign_to_lines
+                    virtual_channel_name = unflattened_lines[0] + '...'
             else:
-                name = lines
+                if name_to_assign_to_lines:
+                    if num_lines > 1:
+                        virtual_channel_name = '{}0:{}'.format(
+                            name_to_assign_to_lines, num_lines-1)
+                    else:
+                        virtual_channel_name = name_to_assign_to_lines
+                else:
+                    virtual_channel_name = lines
 
-        return DIChannel(self._handle, name, self._interpreter)
+        return DIChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_di_chan(
             self, lines, name_to_assign_to_lines="",

generated/nidaqmx/task/collections/_do_channel_collection.py

@@ -1,5 +1,6 @@
 # Do not edit this file; it was automatically generated.
 
+from nidaqmx.errors import DaqFunctionNotSupportedError
 from nidaqmx.task.channels._do_channel import DOChannel
 from nidaqmx.task.collections._channel_collection import ChannelCollection
 from nidaqmx.utils import unflatten_channel_string
@@ -34,25 +35,37 @@ def _create_chan(self, lines, line_grouping, name_to_assign_to_lines=''):
             
             Specifies the newly created DOChannel object.
         """
-        unflattened_lines = unflatten_channel_string(lines)
-        num_lines = len(unflattened_lines)
-        
-        if line_grouping == LineGrouping.CHAN_FOR_ALL_LINES:
-            if name_to_assign_to_lines or num_lines == 1:
-                name = lines
-            else:
-                name = unflattened_lines[0] + '...'
-        else:
-            if name_to_assign_to_lines:
-                if num_lines > 1:
-                    name = '{}0:{}'.format(
-                        name_to_assign_to_lines, num_lines-1)
+        # Attempt to retrieve the last created channel name. This is only supported on DAQmx 24Q3+ with the library
+        # interpreter.
+        virtual_channel_name = None
+        try:
+            virtual_channel_name = self._interpreter.internal_get_last_created_chan()
+        except (NotImplementedError, DaqFunctionNotSupportedError):
+            pass
+
+        # Fallback implementation is sometimes incorrect.
+        if virtual_channel_name is None:
+            unflattened_lines = unflatten_channel_string(lines)
+            num_lines = len(unflattened_lines)
+
+            if line_grouping == LineGrouping.CHAN_FOR_ALL_LINES:
+                if name_to_assign_to_lines:
+                    virtual_channel_name = name_to_assign_to_lines
+                elif num_lines == 1:
+                    virtual_channel_name = lines
                 else:
-                    name = name_to_assign_to_lines
+                    virtual_channel_name = unflattened_lines[0] + '...'
             else:
-                name = lines
+                if name_to_assign_to_lines:
+                    if num_lines > 1:
+                        virtual_channel_name = '{}0:{}'.format(
+                            name_to_assign_to_lines, num_lines-1)
+                    else:
+                        virtual_channel_name = name_to_assign_to_lines
+                else:
+                    virtual_channel_name = lines
 
-        return DOChannel(self._handle, name, self._interpreter)
+        return DOChannel(self._handle, virtual_channel_name, self._interpreter)
 
     def add_do_chan(
             self, lines, name_to_assign_to_lines="",

src/codegen/metadata/functions.py

@@ -17186,6 +17186,32 @@
         'python_codegen_method': 'CustomCode',
         'returns': 'int32'
     },
+    'InternalGetLastCreatedChan': {
+        'calling_convention': 'StdCall',
+        'codegen_method': 'private',
+        'parameters': [
+            {
+                'ctypes_data_type': 'ctypes.c_char_p',
+                'direction': 'out',
+                'name': 'value',
+                'python_data_type': 'str',
+                'size': {
+                    'mechanism': 'ivi-dance',
+                    'value': 'size'
+                },
+                'type': 'char[]'
+            },
+            {
+                'ctypes_data_type': 'ctypes.c_uint32',
+                'direction': 'in',
+                'name': 'size',
+                'python_data_type': 'int',
+                'type': 'uInt32'
+            }
+        ],
+        'python_codegen_method': 'CustomCode',
+        'returns': 'int32'
+    },
     'IsTaskDone': {
         'calling_convention': 'StdCall',
         'handle_parameter': {