feat: add discrete-input support and RPU config-writable check

drivers/modbus_device.py

@@ -94,6 +94,14 @@ class ModbusDevice:
         val = self.read_input_register(address)
         return val - 65536 if val > 32767 else val
 
+    def read_discrete_input(self, address):
+        def _do():
+            res = self.client.read_discrete_inputs(address, count=1, device_id=self.slave_id)
+            if res.isError():
+                raise ModbusReadError(f"{self.device_name}: failed to read discrete input {address}")
+            return res.bits[0]
+        return self._retry(_do)
+
     def read_input_register_float(self, address):
         def _do():
             res = self.client.read_input_registers(address, count=2, device_id=self.slave_id)
@@ -115,14 +123,14 @@ class ModbusDevice:
                 raise ModbusWriteError(f"{self.device_name}: write coil {address}={value} not verified")
         self._retry(_do)
 
-    def write_holding_register(self, address, value):
+    def write_holding_register(self, address, value, verify=True):
         value = int(value) & 0xFFFF  # two's-complement wrap so negative (signed) values fit the uint16 wire format
 
         def _do():
             res = self.client.write_register(address, value, device_id=self.slave_id)
             if res.isError():
                 raise ModbusWriteError(f"{self.device_name}: failed to write holding {address}")
-            if self.read_holding_register(address) != value:
+            if verify and self.read_holding_register(address) != value:
                 raise ModbusWriteError(f"{self.device_name}: write holding {address}={value} not verified")
         self._retry(_do)
 
@@ -155,6 +163,8 @@ class ModbusDevice:
         reg = self._register(label)
         if reg.object_type == "coil":
             return self.read_coil(reg.address)
+        if reg.object_type == "discrete":
+            return self.read_discrete_input(reg.address)
         if reg.object_type == "input":
             if reg.data_type == "float":
                 return self.read_input_register_float(reg.address)
@@ -169,16 +179,16 @@ class ModbusDevice:
             return self.read_holding_register(reg.address)
         raise ModbusDeviceError(f"{self.device_name}: unsupported object_type {reg.object_type!r} for {label!r}")
 
-    def write(self, label, value):
+    def write(self, label, value, verify=True):
         reg = self._register(label)
         if reg.object_type == "coil":
-            self.write_coil(reg.address, value)
+            self.write_coil(reg.address, value, verify=verify)
             return
         if reg.object_type == "holding":
             if reg.data_type == "float":
                 self.write_holding_register_float(reg.address, value)
             else:
-                self.write_holding_register(reg.address, value)
+                self.write_holding_register(reg.address, value, verify=verify)
             return
         raise ModbusDeviceError(f"{self.device_name}: cannot write to object_type {reg.object_type!r} for {label!r}")