feat: add register check

dcm230 contains a both holding and input registers, this is why i add
want to add the check

Signed-off-by: Bobo Bäck Engström <bobo@id8-engineering.io>

Author: Dexter9532

src/dcm230/dcm230.py

@@ -29,7 +29,6 @@ class RegisterSpec:
     Attributes:
         address (int): Modbus register address.
         count (int): Number of consecutive registers to read.
-        scale (int): Scaling factor to apply to the raw integer value.
         decimals (int): Number of decimal places to round the scaled value to.
         writable (bool): Whether this register can be written to.
         range (bool): Whether range validation should be performed.
@@ -39,8 +38,8 @@ class RegisterSpec:
 
     address: int
     count: int
+    reg_type: int
     decimals: int = 0
-    scale: int = 1
     range: bool = False
     min: int = 0
     max: int = 0x7FFFFFFF
@@ -127,7 +126,7 @@ class Dcm230:
     MAX_REGS = 2
 
     _register_specs: Final[dict[str, RegisterSpec]] = {
-        "V": RegisterSpec(address=0x0000, count=2, decimals=1),
+        "V": RegisterSpec(address=0x0000, count=2, decimals=1, reg_type=0x03),
     }
 
     def __init__(self, device_address: int, client: ModbusSerialClient) -> None:
@@ -140,8 +139,8 @@ def __init__(self, device_address: int, client: ModbusSerialClient) -> None:
         self.device_address = device_address
         self.client = client
 
-    def _read_input_registers(self, address: int, count: int) -> list[int]:
-        """Safely read input registers from the Modbus device.
+    def _read_registers(self, address: int, count: int, reg_type: int) -> list[int]:
+        """Safely read input or holding registers from the Modbus device.
 
         Args:
             address: Starting register address to read.
@@ -152,10 +151,20 @@ def _read_input_registers(self, address: int, count: int) -> list[int]:
 
         Raises:
             ModbusException: If the read operation fails or returns an error.
+            ValueError: If register type is incorrect.
         """
-        result = self.client.read_input_registers(
-            address=address, count=count, device_id=self.device_address
-        )
+        if reg_type == 0x03:
+            result = self.client.read_input_registers(
+                address=address, count=count, device_id=self.device_address
+            )
+        elif reg_type == 0x04:
+            result = self.client.read_holding_registers(
+                address=address, count=count, device_id=self.device_address
+            )
+        else:
+            msg = f"Unsupported reg_type: {reg_type}"
+            raise ValueError(msg)
+
         if result.isError():
             msg = (
                 "Failed to read input register. "
@@ -178,7 +187,7 @@ def _read_register(self, register_name: str) -> Decimal | int:
             ModbusException: If Modbus read operation fails.
         """
         spec = self._register_specs[register_name]
-        regs = self._read_input_registers(spec.address, spec.count)
+        regs = self._read_registers(spec.address, spec.count, spec.reg_type)
 
         if len(regs) < self.MAX_REGS:
             regs.append(0)

src/dcm230/test_dcm230.py

@@ -20,8 +20,21 @@ def test_unpack() -> None:
         _ = meter._unpack(registers, 0x0001)  # noqa: SLF001
 
 
+def test_read_register() -> None:
+    """Test read_register."""
+    client = MagicMock()
+    meter = Dcm230(1, client)
+
+    """Test 1: Should raise exception due to incorrect register type"""
+    address = 1
+    count = 2
+    reg_type = 0x05
+    with pytest.raises(ValueError, match="Unsupported reg_type:"):
+        _ = meter._read_registers(address, count, reg_type)
+
+
 def test_V() -> None:
-    """Test Get v."""
+    """test get v."""
     client = MagicMock()
     mock_result = MagicMock()
     mock_result.isError.return_value = False