diff --git a/pykirdy/driver/kirdy.py b/pykirdy/driver/kirdy.py
index 7767dd3..876f5ca 100644
--- a/pykirdy/driver/kirdy.py
+++ b/pykirdy/driver/kirdy.py
@@ -44,6 +44,7 @@ class CmdList:
         SetI = _dt.f32
         SetPdResponsitivity = _dt.f32
         SetPdDarkCurrent = _dt.f32
+        ApplyPdParams = _dt.none
         SetLdPwrLimit = _dt.f32
         ClearAlarm = _dt.none
 
@@ -266,15 +267,19 @@ class Device:
                 'msg_type': 'Settings',             # Indicate it is a 'Settings' json object
                 'laser': {
                     'default_pwr_on': False,        # Power On Laser Diode at Startup
-                    'ld_drive_current': {           # Laser Diode Output Current(A)
+                    'ld_drive_current': {           # Laser Diode Output Current (A)
                        'value': 0.0,                    # Value Set
                        'max': 0.3                       # Max Value Settable
                     },
-                    'pd_mon_params': {              # Laser Diode Software Current Limit(A)
-                       'responsitivity': None,          # Value Set
-                       'i_dark': 0.0                    # Max Value Settable
-                    },   
-                    'ld_pwr_limit': 0.0,            # Laser Diode Power Limit(W)
+                    'pd_mon_params': {              # Photodiode Parameters
+                       'transconductance': 0.000115258765   # Board Specific Transconductance (1/ohm)
+                       'responsitivity': 0.0141,            # Responsitivity (A/W)
+                       'i_dark': 0.0                        # Max Value Settable (A)
+                    },
+                    'ld_pwr_limit': {               # Laser Diode Power Limit (W)
+                        'value': 0.00975,               # Value Set
+                        'max': 0.023321507              # Max Value Settable
+                    },
                     'ld_terms_short: False,         # Is Laser Diode Terminals short? (True/False)
                 }, 
                 'thermostat': {
@@ -282,19 +287,19 @@ class Device:
                     'pid_engaged': True,            # True: PID Control Mode | False Constant Current Mode
                     'temperature_setpoint': 25.0, # Temperature Setpoint (Degree Celsius)
                     'tec_settings': {
-                        'i_set': {                  # Current TEC Current Set by PID Controller/User
+                        'i_set': {                  # Current TEC Current Set by PID Controller/User (A)
                             'value': 0.04330516,        # Value Set
                             'max': 1.0                  # Max Value Settable
                         }, 
-                        'max_v': {                  # Max Voltage Across Tec Terminals
+                        'max_v': {                  # Max Voltage Across Tec Terminals (V)
                             'value': 4.990857,          # Value Set
                             'max': 5.0                  # Max Value Settable
                         }, 
-                        'max_i_pos': {              # Max Cooling Current Across Tec Terminals
+                        'max_i_pos': {              # Max Cooling Current Across Tec Terminals (A)
                             'value': 0.99628574,        # Value Set
                             'max': 1.0                  # Max Value Settable
                         }, 
-                        'max_i_neg': {              # Max Heating Current Across Tec Terminals
+                        'max_i_neg': {              # Max Heating Current Across Tec Terminals (A)
                             'value': 0.99628574,        # Value Set
                             'max': 1.0                  # Max Value Settable
                         }
@@ -396,6 +401,7 @@ class Laser:
     async def set_pd_mon_responsitivity(self, responsitivity):
         """
             Configure the photodiode monitor responsitivity parameter.
+            The value is only effective if ApplyPdParams cmd is issued.
                 - responsitivity: A/W
         """
         return await self._send_cmd(self._cmd._target, self._cmd.SetPdResponsitivity, responsitivity)
@@ -403,16 +409,29 @@ class Laser:
     async def set_pd_mon_dark_current(self, dark_current):
         """
             Configure the photodiode monitor dark current parameter.
+            The value is only effective if ApplyPdParams cmd is issued.
                 - dark_current: A
         """
         return await self._send_cmd(self._cmd._target, self._cmd.SetPdDarkCurrent, dark_current)
 
+    async def apply_pd_params(self):
+        """
+            Evaluate and apply photodiode monitor parameters that are set with SetPdDarkCurrent and SetPdResponsitivity cmd.
+            After Kirdy receives the cmd, it will check if the current power limit is within the newly calculated
+            power limit range. If it is out of range, the photodiode monitor parameters remains unchanged and Kirdy
+            sends out a "InvalidSettings" message along with an error message.
+        """
+        return await self._send_cmd(self._cmd._target, self._cmd.ApplyPdParams)
+
     async def set_ld_pwr_limit(self, pwr_limit):
         """
             Set the power limit for the power excursion monitor.
+            If the power limit settings is out of range, power limit remains unchanged and Kirdy
+            sends out a "InvalidSettings" message along with an error message.
+
             If the calculated power with the params of pd_mon > pwr_limit,
             overpower protection is triggered.
-                - pwr_limit: W 
+                - pwr_limit: W
         """
         return await self._send_cmd(self._cmd._target, self._cmd.SetLdPwrLimit, pwr_limit)
 
@@ -875,20 +894,21 @@ class Kirdy:
         response = raw_response.decode('utf-8', errors='ignore').split("\n")
         return json.loads(response[0])
     
+    def _response_handling(self, msg, msg_type, sig=None):
+        if msg["msg_type"] in ["InvalidCmd", "InvalidDatatype"]:
+            raise InvalidCmd
+        elif msg["msg_type"] == msg_type:
+            if sig is not None:
+                sig.emit(msg)
+        return msg
+
     async def _send_raw_cmd(self, cmd, msg_type="Acknowledge", sig=None):
         if self.connected():
             async with self._lock:
                 self._writer.write(bytes(json.dumps(cmd), "UTF-8"))
                 await self._writer.drain()
                 msg = await asyncio.wait_for(self._int_msg_queue.get(), self._timeout)
-
-            if msg["msg_type"] == msg_type:
-                if sig is not None:
-                    sig.emit(msg)
-                    return {"msg_type": "Acknowledge"}
-                return msg
-            else:
-                raise InvalidCmd
+            return self._response_handling(msg, msg_type, sig)
         else:
             raise ConnectionError
 
@@ -919,12 +939,4 @@ class Kirdy:
             msg = await asyncio.wait_for(self._int_msg_queue.get(), self._timeout)
             if isinstance(msg, Exception):
                 raise msg
-
-        if msg['msg_type'] == msg_type:
-            if sig is not None:
-                sig.emit(msg)
-                return {"msg_type": "Acknowledge"}
-            else:
-                return msg
-        else:
-            raise InvalidCmd
+        return self._response_handling(msg, msg_type, sig)