diff --git a/Software/Integrationtests/tests/TestBase.py b/Software/Integrationtests/tests/TestBase.py
index d1b5d0d..2213005 100644
--- a/Software/Integrationtests/tests/TestBase.py
+++ b/Software/Integrationtests/tests/TestBase.py
@@ -23,7 +23,7 @@ class TestBase(unittest.TestCase):
        
         time.sleep(1)
         
-        self.vna = libreVNA('localhost', 19544)
+        self.vna = libreVNA('localhost', 19544, timeout=4)
         try:
             self.vna.cmd("*CLS;:DEV:CONN")
         except Exception as e:
diff --git a/Software/PC_Application/LibreVNA-GUI/appwindow.cpp b/Software/PC_Application/LibreVNA-GUI/appwindow.cpp
index d89e55a..91aeafd 100644
--- a/Software/PC_Application/LibreVNA-GUI/appwindow.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/appwindow.cpp
@@ -537,10 +537,9 @@ void AppWindow::SetupSCPI()
     }, nullptr, false));
     scpi_dev->add(new SCPICommand("LIST", nullptr, [=](QStringList) -> QString {
         QString ret;
-        for(auto driver : DeviceDriver::getDrivers()) {
-            for(auto d : driver->GetAvailableDevices()) {
-                ret += d + ",";
-            }
+        UpdateDeviceList();
+        for(auto entry : deviceList) {
+            ret += entry.serial + ",";
         }
         // remove last comma
         ret.chop(1);
diff --git a/Software/PC_Application/LibreVNA-GUI/scpi.cpp b/Software/PC_Application/LibreVNA-GUI/scpi.cpp
index 023871b..397e41a 100644
--- a/Software/PC_Application/LibreVNA-GUI/scpi.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/scpi.cpp
@@ -11,6 +11,7 @@ SCPI::SCPI() :
     OCAS = false;
     SESR = 0x00;
     ESE = 0xFF;
+    processing = false;
 
     add(new SCPICommand("*CLS", [=](QStringList) {
         SESR = 0x00;
@@ -178,11 +179,14 @@ QString SCPI::getResultName(SCPI::Result r)
 void SCPI::input(QString line)
 {
     cmdQueue.append(line);
-    process();
+    if(!processing) {
+        process();
+    }
 }
 
 void SCPI::process()
 {
+    processing = true;
     while(!WAIexecuting && !cmdQueue.isEmpty()) {
         auto cmd = cmdQueue.front();
         cmdQueue.pop_front();
@@ -214,6 +218,7 @@ void SCPI::process()
             }
         }
     }
+    processing = false;
 }
 
 void SCPI::someOperationCompleted()
diff --git a/Software/PC_Application/LibreVNA-GUI/scpi.h b/Software/PC_Application/LibreVNA-GUI/scpi.h
index c0e3b15..e206689 100644
--- a/Software/PC_Application/LibreVNA-GUI/scpi.h
+++ b/Software/PC_Application/LibreVNA-GUI/scpi.h
@@ -121,6 +121,7 @@ private:
     bool WAIexecuting;
 
     QList<QString> cmdQueue;
+    bool processing;
 };
 
 #endif // SCPI_H