diff --git a/headers/baseconn.h b/headers/baseconn.h
index e3fed20..928aa1f 100644
--- a/headers/baseconn.h
+++ b/headers/baseconn.h
@@ -67,7 +67,7 @@ private:
     struct waitingRequest {
         int id;
         QEventLoop * loop;
-        QString reply;
+        QJsonObject reply;
     };
 
     QList<waitingRequest> waitingRequests;
@@ -93,12 +93,18 @@ signals:
 
     void nextRemoteActionDelayProgChanged();
 
+    void gotError(QString error);
+
 public slots:
 
     Q_INVOKABLE bool connectToHost();
         //function to connect to the base station
 
-    Q_INVOKABLE QString sendCommand(QString command);
+    Q_INVOKABLE void closeConnection();
+
+    void gotError(QAbstractSocket::SocketError err);
+
+    Q_INVOKABLE QVariantMap sendCommand(int header, QJsonValue data);
 
     Q_INVOKABLE bool refreshConnections();
 
diff --git a/sources/baseconn.cpp b/sources/baseconn.cpp
index c7f2822..e598ec7 100644
--- a/sources/baseconn.cpp
+++ b/sources/baseconn.cpp
@@ -4,7 +4,9 @@ BaseConn::BaseConn(QObject *parent) : QObject(parent)
 {
     socket = new QTcpSocket();
     this->setState("disconnected");
-    remoteSessions.release(1);
+
+    connect(this->socket, SIGNAL(error(QAbstractSocket::SocketError)),
+            this, SLOT(gotError(QAbstractSocket::SocketError)));
 
     this->nextConnectionId = 1;
 
@@ -55,33 +57,91 @@ bool BaseConn::connectToHost() {
     return(true);
 }
 
-QString BaseConn::sendCommand(QString command){
+void BaseConn::closeConnection()
+{
+    qDebug() << "closing connection";
+    switch (socket->state())
+    {
+    case 0:
+        socket->disconnectFromHost();
+        break;
+    case 2:
+        socket->abort();
+        break;
+    default:
+        socket->abort();
+    }
+    setState("disconnected");
+//    for(int i = 0; i < this->waitingRequests.length(); i++){
+//            this->waitingRequests[i].reply = "ERR_NOT_CONNECTED";
+//            this->waitingRequests[i].loop->quit();
+//            return;
+//    }
+}
+
+void BaseConn::gotError(QAbstractSocket::SocketError err)
+{
+    //qDebug() << "got error";
+    QString strError = "unknown";
+    switch (err)
+    {
+        case 0:
+            strError = "Connection was refused";
+            break;
+        case 1:
+            strError = "Remote host closed the connection";
+            this->closeConnection();
+            break;
+        case 2:
+            strError = "Host address was not found";
+            break;
+        case 5:
+            strError = "Connection timed out";
+            break;
+        default:
+            strError = "Unknown error";
+    }
+
+    emit gotError(strError);
+    qDebug() << "got socket error: " << strError;
+}
+
+QVariantMap BaseConn::sendCommand(int header, QJsonValue data = ""){
     if(this->state != "connected"){
-        return "ERR_NOT_CONNECTED";
+        return {{"status", 910}, {"data", "not connected"}};
     }
 
     // generate id and witing requests entry
     int thisId = nextConnectionId;
     nextConnectionId ++;
-    QEventLoop loop;
-    this->waitingRequests.append({thisId, &loop, ""});
 
-    command = "ID:" + QString::number(thisId) + "_"+command;
+    QEventLoop loop;
+    QJsonObject reply;
+
+    this->waitingRequests.append({thisId, &loop, reply});
+
+    QJsonObject requestObj;
+    requestObj.insert("id", thisId);
+    requestObj.insert("header", header);
+    requestObj.insert("data", data);
+
+
+    QString jsonRequest = QJsonDocument(requestObj).toJson();
 
     QByteArray arrBlock;
     QDataStream out(&arrBlock, QIODevice::WriteOnly);
     //out.setVersion(QDataStream::Qt_5_10);
-    out << quint16(0) << command;
+    out << quint16(0) << jsonRequest;
 
     out.device()->seek(0);
-    out << quint16(arrBlock.size() - sizeof(quint16));
+    out << quint16(ulong(arrBlock.size()) - sizeof(quint16));
 
     QTimer timer;
 
     timer.setSingleShot(true);
     // quit the loop when the timer times out
     loop.connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
-    //quit the loop when the connection was established
+    // quit the loop when the connection was established
     // loop.connect(this, &BaseConn::gotReply, &loop, &QEventLoop::quit);
     // start the timer before starting to connect
     timer.start(3000);
@@ -97,11 +157,9 @@ QString BaseConn::sendCommand(QString command){
     if(timer.remainingTime() == -1){
         //the time has been triggered -> timeout
 
-        return("ERR_TIMEOUT");
+        return {{"status", 911}, {"data", ""}};
     }
 
-    QString reply;
-
     for(int i = 0; i<this->waitingRequests.length(); i++){
         if(this->waitingRequests[i].id == thisId){
             reply = this->waitingRequests[i].reply;
@@ -114,7 +172,8 @@ QString BaseConn::sendCommand(QString command){
     timer.deleteLater();
 
     //remoteSessions.release(1);
-    return(reply);
+    return {{"status", reply.value("header").toInt()}, {"data", reply.value("data").toVariant()}};
+
 }
 
 void BaseConn::readyRead() {
@@ -125,7 +184,7 @@ void BaseConn::readyRead() {
     {
         if (!nextBlockSize)
         {
-            if (socket->bytesAvailable() < sizeof(quint16)) { break; }
+            if (ulong(socket->bytesAvailable()) < sizeof(quint16)) { break; }
             in >> nextBlockSize;
         }
 
@@ -142,15 +201,16 @@ void BaseConn::readyRead() {
         nextBlockSize = 0;
         QString reply = str;
         int id = 0;
-        if(reply.startsWith("ID:")){
-            reply.replace("ID:", "");
-            QStringList temp = reply.split("_");
-            reply.replace(temp[0]+"_", "");
-            id = temp[0].toInt();
 
-            for(int i = 0; i<this->waitingRequests.length(); i++){
+        QJsonDocument jsonReply = QJsonDocument::fromJson(reply.toUtf8());
+        QJsonObject replyObj = jsonReply.object();
+
+        if(!replyObj.isEmpty()){
+            id = replyObj.value("id").toInt();
+
+            for(int i = 0; i < this->waitingRequests.length(); i++){
                 if(this->waitingRequests[i].id == id){
-                    this->waitingRequests[i].reply = reply;
+                    this->waitingRequests[i].reply = replyObj;
                     this->waitingRequests[i].loop->quit();
                     return;
                 }
@@ -176,20 +236,20 @@ void BaseConn::refreshTimers(){
     QString tmpNextRemoteAction;
     QString tmpNextRemoteActionDelayProg;
 
-    remoteState = sendCommand("GET_TIMER_STATE");
+    remoteState = sendCommand(2000)["data"].toString();
 
     switch (speedTimers[0]->state) {
     case SpeedTimer::IDLE:
         break;
     case SpeedTimer::STARTING:
-        if(remoteState == "RUNNING"){
+        if(remoteState == "2"){
             speedTimers[0]->start();
         }
-        else if (remoteState == "STOPPED") {
+        else if (remoteState == "3") {
             speedTimers[0]->stop("manual");
         }
 
-        tmpNextRemoteAction = sendCommand("GET_NEXT_ACTION");
+        tmpNextRemoteAction = sendCommand(2004)["data"].toString();
         if(tmpNextRemoteAction.startsWith("ERR")){
             //handle Error!!
         }
@@ -200,7 +260,7 @@ void BaseConn::refreshTimers(){
             }
         }
 
-        tmpNextRemoteActionDelayProg = sendCommand("GET_NEXT_ACTION_DELAY_PROG");
+        tmpNextRemoteActionDelayProg = sendCommand(2005)["data"].toFloat();
         if(tmpNextRemoteActionDelayProg.startsWith("ERR")){
             //handle error!!
         }
@@ -214,7 +274,7 @@ void BaseConn::refreshTimers(){
         break;
     case SpeedTimer::RUNNING:
 
-        if(remoteState == "STOPPED"){
+        if(remoteState == "2"){
             speedTimers[0]->stop("manual");
         }
         remoteTime = sendCommand("GET_CURRTIME");