Update channel interface

handel/interface.py

@@ -20,6 +20,7 @@ __all__ = ['init', 'init_handel', 'exit',
            'set_log_output', 'set_log_level', 'close_log',
            'get_num_modules', 'get_modules', 'get_module_from_channel',
            'get_module_type', 'get_module_interface',
+           'get_module_channels', 'get_grouped_channels', 'get_channels',
            'set_acquisition_value', 'get_acquisition_value',
            'remove_acquisition_value', 'apply_acquisition_values',
            'get_handel_version']
@@ -291,16 +292,21 @@ def get_module_channel_at(alias, index):
 def get_module_channels(alias):
     """Return the module channels properly indexed."""
     number_of_channels = get_module_number_of_channels(alias)
-    return tuple(
-        get_module_channel_at(alias, index)
-        for index in range(number_of_channels))
+    return tuple(get_module_channel_at(alias, index)
+                 for index in range(number_of_channels))
 
 
-def get_all_channels():
+def get_grouped_channels():
     """Return the indexed channels grouped by modules."""
     return tuple(get_module_channels(alias) for alias in get_modules())
 
 
+def get_channels():
+    """Return all the enabled channels."""
+    return sorted(channel for channels in get_grouped_channels()
+                  for channel in channels if channel != -1)
+
+
 # Not exposed
 
 # int xiaNewModule(char *alias);