diff --git a/platform/qt/dmxwidget/dmxwidget.cpp b/platform/qt/dmxwidget/dmxwidget.cpp
index a3f5a69..23a8bc8 100644
--- a/platform/qt/dmxwidget/dmxwidget.cpp
+++ b/platform/qt/dmxwidget/dmxwidget.cpp
@@ -28,10 +28,6 @@ DmxWidget::DmxWidget(QObject *parent)
     , port_(new QSerialPort(this))
 {
   connect(this, &DmxWidget::serialDataRead, this, &DmxWidget::parseMessageBuffer);
-  connect(port_, &QSerialPort::readyRead, this, [this]() {
-      message_rx_buffer_.append(port_->readAll());
-      emit serialDataRead();
-  });
 }
 
 
@@ -46,6 +42,33 @@ void DmxWidget::open()
   if (!port_->open(QIODeviceBase::ReadWrite))
       return;
   ENTTEC::Widget::open();
+
+  getSerialNumber();
+  getParameters(0);
+  if (port_->waitForReadyRead(500) && port_->bytesAvailable() >= 19)
+  {
+    char snhead[] = {ENTTEC::Pro::START_DELIMITER,
+                     ENTTEC::Pro::OpGetWidgetSerial,
+                     0x04, 0x00}; // expect 4 bytes of message data
+    message_rx_buffer_.append(port_->readAll());
+    if (!message_rx_buffer_.startsWith(snhead))
+    {
+      message_rx_buffer_.clear();
+      close();
+      return;
+    }
+    parseMessageBuffer();
+  }
+  else
+  {
+    close();
+    return;
+  }
+
+  connect(port_, &QSerialPort::readyRead, this, [this]() {
+      message_rx_buffer_.append(port_->readAll());
+      emit serialDataRead();
+  });
   emit connectedChanged(isConnected());
 }
 
@@ -53,6 +76,7 @@ void DmxWidget::open()
 void DmxWidget::close()
 {
   port_->close();
+  disconnect(port_, &QSerialPort::readyRead, nullptr, nullptr);
   ENTTEC::Widget::close();
   emit connectedChanged(isConnected());
 }