diff --git a/srnemqtt/protocol.py b/srnemqtt/protocol.py
index be711ef..50cfc06 100644
--- a/srnemqtt/protocol.py
+++ b/srnemqtt/protocol.py
@@ -212,7 +212,7 @@ class ChargeController:
     def serial(self) -> str:
         data = readMemory(self.device, 0x18, 3)
         if data is None:
-            raise IOError
+            raise IOError  # FIXME: Raise specific error in readMemory
 
         p1 = data[0]
         p2 = data[1]
@@ -223,7 +223,7 @@ class ChargeController:
     def model(self) -> str:
         data = readMemory(self.device, 0x0C, 8)
         if data is None:
-            raise IOError
+            raise IOError  # FIXME: Raise specific error in readMemory
 
         return data.decode("utf-8").strip()
 
@@ -231,7 +231,7 @@ class ChargeController:
     def version(self) -> str:
         data = readMemory(self.device, 0x14, 4)
         if data is None:
-            raise IOError
+            raise IOError  # FIXME: Raise specific error in readMemory
 
         major = (data[0] << 8) + data[1]
         minor = data[2]
@@ -243,7 +243,7 @@ class ChargeController:
     def load_enabled(self) -> bool:
         data = readMemory(self.device, 0x010A, 1)
         if data is None:
-            raise IOError
+            raise IOError  # FIXME: Raise specific error in readMemory
 
         return struct.unpack("x?", data)[0]