diff --git a/src/ebusd/mainloop.cpp b/src/ebusd/mainloop.cpp
index a295e41f..f7d55bbe 100644
--- a/src/ebusd/mainloop.cpp
+++ b/src/ebusd/mainloop.cpp
@@ -474,6 +474,14 @@ void MainLoop::notifyDeviceData(symbol_t symbol, bool received) {
   }
 }
 
+void MainLoop::notifyStatus(bool error, const char* message) {
+  if (error) {
+    logError(lf_bus, "device status: %s", message);
+  } else {
+    logNotice(lf_bus, "device status: %s", message);
+  }
+}
+
 result_t MainLoop::decodeMessage(const string &data, bool isHttp, bool* connected, ClientSettings* settings,
     string* user, bool* reload, ostringstream* ostream) {
   string token, previous;
diff --git a/src/ebusd/mainloop.h b/src/ebusd/mainloop.h
index 742ce866..f4ba8208 100644
--- a/src/ebusd/mainloop.h
+++ b/src/ebusd/mainloop.h
@@ -132,6 +132,9 @@ class MainLoop : public Thread, DeviceListener {
   // @copydoc
   void notifyDeviceData(symbol_t symbol, bool received) override;
 
+  // @copydoc
+  void notifyStatus(bool error, const char* message) override;
+
 
  protected:
   // @copydoc
diff --git a/src/lib/ebus/device.cpp b/src/lib/ebus/device.cpp
index b7434e8b..3dd787c6 100755
--- a/src/lib/ebus/device.cpp
+++ b/src/lib/ebus/device.cpp
@@ -148,6 +148,22 @@ result_t Device::open() {
   return m_bufSize == 0 ? RESULT_ERR_DEVICE : RESULT_OK;
 }
 
+result_t Device::afterOpen() {
+  m_bufLen = 0;
+  if (m_enhancedProto) {
+    symbol_t buf[2] = makeEnhancedSequence(ENH_REQ_INIT, 0); // TODO define additional feature flags
+    if (::write(m_fd, buf, 2) != 2) {
+      return RESULT_ERR_SEND;
+    }
+    if (m_listener != nullptr) {
+      m_listener->notifyStatus(false, "resetting");
+    }
+  } else if (m_initialSend && !write(ESC)) {
+    return RESULT_ERR_SEND;
+  }
+  return RESULT_OK;
+}
+
 void Device::close() {
   if (m_fd != -1) {
     ::close(m_fd);
@@ -181,9 +197,10 @@ result_t Device::send(symbol_t value) {
 
 /**
  * the maximum duration to wait for an enhanced sequence to complete after the first part was already retrieved:
- * Start+8Bit+Stop+Extra @ 9600Bd.
+ * 2* (Start+8Bit+Stop+Extra @ 9600Bd)
  */
-#define ENHANCED_COMPLETE_WAIT_DURATION 1150
+#define ENHANCED_COMPLETE_WAIT_DURATION (2*1150)
+
 
 result_t Device::recv(unsigned int timeout, symbol_t* value, ArbitrationState* arbitrationState) {
   if (!isValid()) {
@@ -272,6 +289,7 @@ result_t Device::recv(unsigned int timeout, symbol_t* value, ArbitrationState* a
     }
     return RESULT_OK;
   }
+  // non-enhanced: arbitration executed by ebusd itself
   bool wrote = write(m_arbitrationMaster);  // send as fast as possible
   if (m_listener != nullptr) {
     m_listener->notifyDeviceData(*value, true);
@@ -282,7 +300,7 @@ result_t Device::recv(unsigned int timeout, symbol_t* value, ArbitrationState* a
     m_arbitrationCheck = false;
     return RESULT_OK;
   }
-  if (m_listener != NULL) {
+  if (m_listener != nullptr) {
     m_listener->notifyDeviceData(m_arbitrationMaster, false);
   }
   m_arbitrationCheck = true;
@@ -292,7 +310,7 @@ result_t Device::recv(unsigned int timeout, symbol_t* value, ArbitrationState* a
 
 result_t Device::startArbitration(symbol_t masterAddress) {
   if (m_arbitrationCheck) {
-    return RESULT_ERR_DUPLICATE;
+    return RESULT_ERR_SEND; // should not occur
   }
   if (m_readOnly) {
     return RESULT_ERR_SEND;
@@ -331,9 +349,26 @@ bool Device::available() {
       return true;
     }
     if ((ch&ENH_BYTE_MASK) == ENH_BYTE1) {
-      return pos+1 < m_bufLen;
+      if (pos+1 >= m_bufLen) {
+        return false;
+      }
+      // peek into next byte to check if enhanced sequence is ok
+      ch = m_buffer[(pos+m_bufPos+1)%m_bufSize];
+      if (!(ch&ENH_BYTE_FLAG) || (ch&ENH_BYTE_MASK) != ENH_BYTE2) {
+        if (m_listener != nullptr) {
+          m_listener->notifyStatus(true, "unexpected available enhanced following byte 1");
+        }
+        // drop first byte of invalid sequence
+        m_bufPos = (m_bufPos + 1) % m_bufSize;
+        m_bufLen--;
+        pos--;
+        continue;
+      }
+      return true;
+    }
+    if (m_listener != nullptr) {
+      m_listener->notifyStatus(true, "unexpected available enhanced byte 2");
     }
-    // TODO protocol error
     // skip byte from erroneous protocol
     m_bufPos = (m_bufPos+1)%m_bufSize;
     m_bufLen--;
@@ -347,7 +382,10 @@ bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrati
     if (m_bufLen > 0 && m_bufPos != 0) {
       if (m_bufLen > m_bufSize / 2) {
         // more than half of input buffer consumed is taken as signal that ebusd is too slow
-        m_bufLen = 0; // TODO report error
+        m_bufLen = 0;
+        if (m_listener != nullptr) {
+          m_listener->notifyStatus(true, "buffer overflow");
+        }
       } else {
         size_t tail;
         if (m_bufPos+m_bufLen > m_bufSize) {
@@ -397,31 +435,33 @@ bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrati
     m_bufPos = (m_bufPos+1)%m_bufSize;
     m_bufLen--;
     if (kind == ENH_BYTE2) {
-      return false; // TODO protocol error
+      if (m_listener != nullptr) {
+        m_listener->notifyStatus(true, "unexpected enhanced byte 2");
+      }
+      return false;
     }
     // kind is ENH_BYTE1
     symbol_t ch2 = m_buffer[m_bufPos];
     m_bufPos = (m_bufPos + 1) % m_bufSize;
     m_bufLen--;
     if ((ch2 & ENH_BYTE_MASK) != ENH_BYTE2) {
-      return false; // TODO protocol error
+      if (m_listener != nullptr) {
+        m_listener->notifyStatus(true, "missing enhanced byte 2");
+      }
+      return false;
     }
     ch2 = (symbol_t)(((ch&0x03)<<6) | (ch2&0x3f));
     ch = (ch>>2)&0xf;
     switch (ch) {
       case ENH_RES_STARTED:
         *arbitrationState = as_won;
-        if (m_listener != NULL) {
-          m_listener->notifyDeviceData(ch2, false);
-        }
         m_arbitrationMaster = SYN;
+        m_arbitrationCheck = false;
         break;
       case ENH_RES_FAILED:
-        *arbitrationState = as_error;
-        if (m_listener != NULL) {
-          m_listener->notifyDeviceData(ch2, false);
-        }
+        *arbitrationState = as_lost;
         m_arbitrationMaster = SYN;
+        m_arbitrationCheck = false;
         break;
       case ENH_RES_RECEIVED:
         *value = ch2;
@@ -431,9 +471,14 @@ bool Device::read(symbol_t* value, bool isAvailable, ArbitrationState* arbitrati
           *arbitrationState = as_error;
         }
         // TODO define additional feature flags
+        if (m_listener != nullptr) {
+          m_listener->notifyStatus(false, "reset");
+        }
         break;
       default:
-        // TODO protocol error
+        if (m_listener != nullptr) {
+          m_listener->notifyStatus(true, "unexpected enhanced command");
+        }
         return false;
     }
   }
@@ -510,15 +555,7 @@ result_t SerialDevice::open() {
   // set serial device into blocking mode
   fcntl(m_fd, F_SETFL, fcntl(m_fd, F_GETFL) & ~O_NONBLOCK);
 
-  if (m_enhancedProto) {
-    symbol_t buf[2] = makeEnhancedSequence(ENH_REQ_INIT, 0); // TODO define additional feature flags
-    if (::write(m_fd, buf, 2) != 2) {
-      return RESULT_ERR_SEND;
-    }
-  } else if (m_initialSend && !write(ESC)) {
-    return RESULT_ERR_SEND;
-  }
-  return RESULT_OK;
+  return afterOpen();
 }
 
 void SerialDevice::close() {
@@ -601,11 +638,7 @@ result_t NetworkDevice::open() {
     close();
     return RESULT_ERR_GENERIC_IO;
   }
-  m_bufLen = 0;
-  if (m_initialSend && !write(ESC)) {
-    return RESULT_ERR_SEND;
-  }
-  return RESULT_OK;
+  return afterOpen();
 }
 
 void NetworkDevice::checkDevice() {
diff --git a/src/lib/ebus/device.h b/src/lib/ebus/device.h
index 925f4aab..b4a8290c 100755
--- a/src/lib/ebus/device.h
+++ b/src/lib/ebus/device.h
@@ -66,6 +66,13 @@ class DeviceListener {
    * @param received @a true on reception, @a false on sending.
    */
   virtual void notifyDeviceData(symbol_t symbol, bool received) = 0;  // abstract
+
+  /**
+   * Called to notify a status message from the device.
+   * @param error true for an error message, false for an info message.
+   * @param message the message string.
+   */
+  virtual void notifyStatus(bool error, const char* message) = 0;  // abstract
 };
 
 
@@ -113,6 +120,12 @@ class Device {
    */
   virtual result_t open();
 
+  /**
+   * Has to be called by subclasses upon successful opening the device as last action in open().
+   * @return the @a result_t code.
+   */
+  result_t afterOpen();
+
   /**
    * Close the file descriptor if opened.
    */
@@ -225,7 +238,7 @@ class Device {
 
  private:
   /** the @a DeviceListener, or nullptr. */
-public: DeviceListener* m_listener;
+  DeviceListener* m_listener;
 
   /** the arbitration master address to send when in arbitration, or @a SYN. */
   symbol_t m_arbitrationMaster;