Interface for instantiating, reading and writing extended for more compact type save coding style

src/pyhoff/__init__.py

@@ -1,5 +1,12 @@
 from .modbus import SimpleModbusClient
-from typing import Type
+from typing import Type, Iterable
+
+
+def _is_bus_terminal(bt_type: Type['BusTerminal']) -> bool:
+    if BusTerminal.__name__ == bt_type.__name__:
+        return True
+
+    return any(_is_bus_terminal(b) for b in bt_type.__bases__)
 
 
 class BusTerminal():
@@ -33,6 +40,13 @@ class BusTerminal():
         self._input_word_addresses = input_word_addresses
         self._mixed_mapping = mixed_mapping
 
+    @classmethod
+    def select(cls, bus_coupler: 'BusCoupler', terminal_number: int = 0):
+        terminal_list = [bt for bt in bus_coupler.bus_terminals if isinstance(bt, cls)]
+        assert terminal_list, f'No instance of {cls.__name__} configured at this BusCoupler'
+        assert 0 <= terminal_number < len(terminal_list), f'Out of range, select in range: 0..{len(terminal_list)-1}'
+        return terminal_list[terminal_number]
+
 
 class DigitalInputTerminal(BusTerminal):
     """
@@ -145,7 +159,7 @@ class AnalogOutputTerminal(BusTerminal):
             channel: The channel number (1 based index) to read from.
 
         Returns:
-            The read word value.
+            The read word value or provided error_value if read failed.
 
         Raises:
             Exception: If the word offset or count is out of range.
@@ -158,7 +172,7 @@ class AnalogOutputTerminal(BusTerminal):
 
         return value[0] if value else error_value
 
-    def write_channel_word(self, channel: int, value: int) -> int:
+    def write_channel_word(self, channel: int, value: int) -> bool:
         """
         Write a word to the terminal.
 
@@ -176,15 +190,18 @@ class AnalogOutputTerminal(BusTerminal):
 
         return self.bus_coupler.modbus.write_single_register(self._output_word_addresses[channel - 1], value)
 
-    def set_normalized(self, channel: int, value: float):
+    def set_normalized(self, channel: int, value: float) -> bool:
         """
         Set a normalized value between 0 and 1 to a specific channel.
 
         Args:
             channel: The channel number to set.
             value: The normalized value to set.
+
+        Returns:
+            True if the write operation succeeded.
         """
-        self.write_channel_word(channel, int(value * 0x7FFF))
+        return self.write_channel_word(channel, int(value * 0x7FFF))
 
 
 class BusCoupler():
@@ -214,7 +231,7 @@ class BusCoupler():
         Temperature ch1: 23.2 °C, Temperature ch2: 22.1 °C
     """
 
-    def __init__(self, host: str, port: int = 502, bus_terminals: list[Type[BusTerminal]] = [],
+    def __init__(self, host: str, port: int = 502, bus_terminals: Iterable[Type[BusTerminal]] = [],
                  timeout: float = 5, watchdog: float = 0, debug: bool = False):
 
         self.bus_terminals: list[BusTerminal] = list()
@@ -233,19 +250,27 @@ class BusCoupler():
     def _init_hardware(self, watchdog: float):
         pass
 
-    def add_bus_terminals(self, bus_terminals: list[Type[BusTerminal]]) -> list[BusTerminal]:
+    def add_bus_terminals(self, *new_bus_terminals: Type[BusTerminal] | Iterable[Type[BusTerminal]]) -> list[BusTerminal]:
         """
         Add bus terminals to the bus coupler.
 
         Args:
-            bus_terminals: A list of bus terminal classes to add.
+            new_bus_terminals: bus terminal classes to add.
 
         Returns:
             The corresponding list of bus terminal objects.
         """
 
-        for terminal_class in bus_terminals:
-            assert issubclass(terminal_class, BusTerminal), f'{terminal_class} is not a bus terminal'
+        terminal_classes: list[Type[BusTerminal]] = []
+        for element in new_bus_terminals:
+            if isinstance(element, Iterable):
+                for bt in element:
+                    terminal_classes.append(bt)
+            else:
+                terminal_classes.append(element)
+
+        for terminal_class in terminal_classes:
+            assert _is_bus_terminal(terminal_class), f'{terminal_class} is not a bus terminal'
 
             def get_para(key: str):
                 return terminal_class.parameters.get(key, 0)