diff --git a/src/datIf.cpp b/src/datIf.cpp
index ea18f4e..8a5b675 100755
--- a/src/datIf.cpp
+++ b/src/datIf.cpp
@@ -551,26 +551,40 @@ char T_datif::loadRecDataFromFrame()
     if (myDCIF && myDCIF->getSerialPort()) {
         QVector<uint16_t> &readCmds = myDCIF->getSerialPort()->getReadCmds();
 
-        if (readCmds.size() == 1) {
+        if (readCmds.size() == 1) { // there can be only one command been sent to the DC
+            // the command number active at the moment must be the same as the saved one
             if (readSource == myDCIF->getReadSource() && readSource == readCmds[0]) {
+                // maybe we have sent a explicit request for a test-response
                 if (waitForTestResponse) {
                     if (readCmds[0] == CMD2DC_TestSerial) {
                         if (QString(QByteArray((char const *)receivedData, RdDleng)) == "< SlaveResponse") {
                             waitForTestResponse = false;
-                            ((hwapi *)parent())->dc_autoRequest(true);
+                            qCritical() << __func__ << ":" << __LINE__ << "turn on auto-request";
+                            ((hwapi *)parent())->dc_autoRequest(true); // return autorequest to true
+                        } else {
+                            qCritical() << __func__ << ":" << __LINE__ << "received wrong test-response"
+                                        << QString(QByteArray((char const *)receivedData, RdDleng));
                         }
                     }
+                } else {
+                    // usual handling of response
                 }
                 readCmds.clear();
-            } else {
+            } else { // error
                 qCritical() << __func__ << ":" << __LINE__ << ":" << readSource << myDCIF->getReadSource() << readCmds[0];
                 qCritical() << __func__ << ":" << __LINE__ << ":" << QByteArray((char const *)receivedData, RdDleng).toHex(':');
                 readCmds.clear();
                 return 0;
             }
         } else {
+            // error: read commands has not size 1 as it should be: turn off
+            // auto requests and send explicit request for test-response:
+            // once this response has been received, turn on the autmatic requests
+            // again.
             readCmds.clear();
             if (parent()) {
+                qCritical() << __func__ << ":" << __LINE__ << "turn off auto-request";
+                qCritical() << __func__ << ":" << __LINE__ << "send request for test-response";
                 waitForTestResponse = true;
                 ((hwapi *)parent())->dc_autoRequest(false);
                 ((hwapi *)parent())->dc_requTestResponse();