diff --git a/cflib/crazyflie/platformservice.py b/cflib/crazyflie/platformservice.py
index e1c8d398c..8b96c214a 100644
--- a/cflib/crazyflie/platformservice.py
+++ b/cflib/crazyflie/platformservice.py
@@ -40,6 +40,7 @@
 APP_CHANNEL = 2
 
 PLATFORM_SET_CONT_WAVE = 0
+PLATFORM_REQUEST_ARMING = 1
 
 VERSION_GET_PROTOCOL = 0
 VERSION_GET_FIRMWARE = 1
@@ -82,7 +83,20 @@ def set_continous_wave(self, enabled):
         """
         pk = CRTPPacket()
         pk.set_header(CRTPPort.PLATFORM, PLATFORM_COMMAND)
-        pk.data = (0, enabled)
+
+        pk.data = (PLATFORM_SET_CONT_WAVE, enabled)
+        self._cf.send_packet(pk)
+
+    def send_arming_request(self, do_arm: bool):
+        """
+        Send system arm/disarm request
+
+        Args:
+            do_arm (bool): True = arm the system, False = disarm the system
+        """
+        pk = CRTPPacket()
+        pk.set_header(CRTPPort.PLATFORM, PLATFORM_COMMAND)
+        pk.data = (PLATFORM_REQUEST_ARMING, do_arm)
         self._cf.send_packet(pk)
 
     def get_protocol_version(self):
diff --git a/cflib/drivers/cfusb.py b/cflib/drivers/cfusb.py
index 124e27061..80d12a321 100644
--- a/cflib/drivers/cfusb.py
+++ b/cflib/drivers/cfusb.py
@@ -102,9 +102,10 @@ def __init__(self, device=None, devid=0):
                         self.dev.set_configuration()
 
         self.handle = self.dev
-        self.version = float(
-            '{0:x}.{1:x}'.format(self.dev.bcdDevice >> 8,
-                                 self.dev.bcdDevice & 0x0FF))
+        if self.dev:
+            self.version = float('{0:x}.{1:x}'.format(self.dev.bcdDevice >> 8, self.dev.bcdDevice & 0x0FF))
+        else:
+            self.version = 0.0
 
     def get_serial(self):
         # The signature for get_string has changed between versions to 1.0.0b1,