diff --git a/DSView/main.cpp b/DSView/main.cpp
index dce0339f..60ae81b0 100644
--- a/DSView/main.cpp
+++ b/DSView/main.cpp
@@ -185,20 +185,30 @@ bool bHighScale = true;
 	#ifdef DEBUG_INFO
 		if (XLOG_LEVEL_INFO > logLevel){
 			dsv_log_level(XLOG_LEVEL_INFO); // on develop mode, set the default log ldevel
+			logLevel = XLOG_LEVEL_INFO;
 		}
 	#endif
 
 	if (bStoreLog){
-		dsv_log_enalbe_logfile();
+		dsv_log_enalbe_logfile(true);
 	} 
 
+	AppControl *control = AppControl::Instance();	
+	AppConfig &app = AppConfig::Instance(); 
+	app.LoadAll(); //load app config
+
+	if (app._appOptions.ableSaveLog){
+		dsv_log_enalbe_logfile(false);
+
+		if (app._appOptions.logLevel >= logLevel){
+			dsv_log_level(app._appOptions.logLevel);
+		}
+	}
+
 	//----------------------run
 	dsv_info("----------------- version: %s-----------------", DS_VERSION_STRING);
 	dsv_info("Qt:%s", QT_VERSION_STR);
 
-	AppControl *control = AppControl::Instance();	
-	AppConfig::Instance().LoadAll(); //load app config
-
 	//init core
 	if (!control->Init()){ 
 		dsv_err("%s", "init error!");
diff --git a/DSView/pv/appcontrol.cpp b/DSView/pv/appcontrol.cpp
index b34dfd1f..911b496a 100644
--- a/DSView/pv/appcontrol.cpp
+++ b/DSView/pv/appcontrol.cpp
@@ -25,13 +25,13 @@
 #include <libsigrokdecode.h>
 #include <QDir>
 #include <QCoreApplication>
-#include <QWidget> 
+#include <QWidget>
+#include <string>
 #include "sigsession.h"
 #include "dsvdef.h"
 #include "config/appconfig.h"
 #include "log.h"
-#include <QTextCodec>
-#include <string.h>
+#include "utility/path.h"
 
 AppControl::AppControl()
 {
@@ -66,7 +66,7 @@ bool AppControl::Init()
 {    
     _session->init();
 
-    srd_log_set_context(dsv_log_context());     
+    srd_log_set_context(dsv_log_context());
 
 #if defined(_WIN32) && defined(DEBUG_INFO)
     //able run debug with qtcreator
diff --git a/DSView/pv/config/appconfig.cpp b/DSView/pv/config/appconfig.cpp
index 3d72b46a..78ad1470 100644
--- a/DSView/pv/config/appconfig.cpp
+++ b/DSView/pv/config/appconfig.cpp
@@ -94,6 +94,8 @@ void _loadApp(AppOptions &o, QSettings &st){
     getFiled("quickScroll", st, o.quickScroll, true);
     getFiled("warnofMultiTrig", st, o.warnofMultiTrig, true);
     getFiled("originalData", st, o.originalData, false);
+    getFiled("ableSaveLog", st, o.ableSaveLog, false);
+    getFiled("logLevel", st, o.logLevel, 3);
 
     QString fmt;
     getFiled("protocalFormats", st, fmt, "");
@@ -109,6 +111,8 @@ void _saveApp(AppOptions &o, QSettings &st){
     setFiled("quickScroll", st, o.quickScroll);
     setFiled("warnofMultiTrig", st, o.warnofMultiTrig);
     setFiled("originalData", st, o.originalData);
+    setFiled("ableSaveLog", st, o.ableSaveLog);
+    setFiled("logLevel", st, o.logLevel);
 
     QString fmt =  FormatArrayToString(o.m_protocolFormats);
     setFiled("protocalFormats", st, fmt);
@@ -238,6 +242,8 @@ void AppConfig::LoadAll()
     _loadApp(_appOptions, st);
     _loadHistory(_userHistory, st);
     _loadFrame(_frameOptions, st);
+
+    //dsv_dbg("Config file path:\"%s\"", st.fileName().toUtf8().data());
 }
 
   void AppConfig::SaveApp()
diff --git a/DSView/pv/config/appconfig.h b/DSView/pv/config/appconfig.h
index bf300a97..49eca089 100644
--- a/DSView/pv/config/appconfig.h
+++ b/DSView/pv/config/appconfig.h
@@ -57,6 +57,8 @@ struct AppOptions
     bool  quickScroll;
     bool  warnofMultiTrig;
     bool  originalData;
+    bool  ableSaveLog;
+    int   logLevel;
 
     std::vector<StringPair> m_protocolFormats;
 };
diff --git a/DSView/pv/log.cpp b/DSView/pv/log.cpp
index a5eb4bee..6f151b0f 100644
--- a/DSView/pv/log.cpp
+++ b/DSView/pv/log.cpp
@@ -23,10 +23,13 @@
 #include <QString>
 #include <QDir>
 #include  "config/appconfig.h"
+#include "utility/path.h"
+#include <string>
 
 xlog_writer *dsv_log = nullptr;
 static xlog_context *log_ctx = nullptr;
-bool b_logfile = false;
+static bool b_logfile = false;
+static int log_file_index = -1;
 
 void dsv_log_init()
 {
@@ -52,10 +55,10 @@ xlog_context* dsv_log_context()
 void dsv_log_level(int l)
 {
     xlog_set_level(log_ctx, l);
-    dsv_info("%s%d", "set log level: ", l);
+    dsv_info("%s%d", "Set log level: ", l);
 }
 
-void dsv_log_enalbe_logfile()
+void dsv_log_enalbe_logfile(bool append)
 {
     if (!b_logfile && log_ctx){
         b_logfile = true;
@@ -68,11 +71,22 @@ void dsv_log_enalbe_logfile()
             lf = GetAppDataDir() + "/DSView.log";
         #endif
 
-        dsv_info("%s\"%s\"", "store log to file: ", lf.toUtf8().data());
+        dsv_info("%s\"%s\"", "Store log to file: ", lf.toUtf8().data());
 
-        int ret = xlog_add_receiver_from_file(log_ctx, lf.toUtf8().data(), 0);
+        std::string log_file = pv::path::ToUnicodePath(lf);
+
+        int ret = xlog_add_receiver_from_file(log_ctx, log_file.c_str(), &log_file_index, append);
         if (ret != 0){
-            dsv_err("%s", "create log file error!");
-        } 
+            dsv_err("%s", "Create log file error!");
+        }
+    }
+}
+
+void dsv_remove_log_file()
+{
+    if (b_logfile && log_ctx)
+    {
+        b_logfile = false;
+        xlog_remove_receiver_by_index(log_ctx, log_file_index);
     }
 }
\ No newline at end of file
diff --git a/DSView/pv/log.h b/DSView/pv/log.h
index d3ca912b..ae96da1f 100644
--- a/DSView/pv/log.h
+++ b/DSView/pv/log.h
@@ -32,7 +32,8 @@ void dsv_log_uninit();
 xlog_context* dsv_log_context();
 void dsv_log_level(int l);
 
-void dsv_log_enalbe_logfile();
+void dsv_log_enalbe_logfile(bool append);
+void dsv_remove_log_file();
 
 #define LOG_PREFIX "" 
 #define dsv_err(fmt, args...) xlog_err(dsv_log, LOG_PREFIX fmt, ## args)
diff --git a/DSView/pv/sigsession.cpp b/DSView/pv/sigsession.cpp
index c97f3f98..cf612281 100644
--- a/DSView/pv/sigsession.cpp
+++ b/DSView/pv/sigsession.cpp
@@ -60,6 +60,7 @@
 #include "dsvdef.h"
 #include "log.h"
 #include "config/appconfig.h"
+#include "utility/path.h"
  
 namespace pv {
 
@@ -110,8 +111,6 @@ SigSession::SigSession()
     _group_data = new data::Group();
     _group_cnt = 0;
 
-    _sr_ctx = NULL;
-
     _feed_timer.Stop(); 
     _feed_timer.SetCallback(std::bind(&SigSession::feed_timeout, this)); 
 }
@@ -145,8 +144,7 @@ void SigSession::set_device(DevInst *dev_inst)
 
     RELEASE_ARRAY(_group_traces);
  
-    if (_dev_inst) {
-        sr_session_datafeed_callback_remove_all();
+    if (_dev_inst) { 
         _dev_inst->release();
         _dev_inst = NULL;
     }
@@ -1887,6 +1885,17 @@ void SigSession::set_stop_scale(float scale)
       _bDecodeRunning = false;
   }
 
+  void SigSession::get_device_list(std::vector<struct ds_device_info> &devices)
+  {
+        struct ds_device_info *array = NULL;
+        int num = 0;
+
+        if (ds_get_device_list(&array, &num) != SR_OK){
+           dsv_err("%s", "Failed to get device list!");
+           return;
+        }
+  }
+
   void SigSession::device_lib_event_callback(int event)
   {
        struct ds_device_info *array = NULL;
@@ -1917,16 +1926,10 @@ void SigSession::set_stop_scale(float scale)
 
       ds_set_datafeed_callback(data_feed_callback);
 
+      // firmware resource directory
       QString resdir = GetResourceDir();
-      char res_path[256] = {0};
-#ifdef _WIN32
-      QTextCodec *codec = QTextCodec::codecForName("System");
-      QByteArray str_tmp = codec->fromUnicode(resdir);
-      strncpy(res_path, str_tmp.data(), sizeof(res_path) - 1);
-#else
-      strncpy(res_path, resdir.toUtf8().data(), sizeof(res_path) - 1);
-#endif
-      ds_set_firmware_resource_dir(res_path);
+      std::string res_path = pv::path::ToUnicodePath(resdir);
+      ds_set_firmware_resource_dir(res_path.c_str());
 
       if (ds_lib_init() != SR_OK)
       { 
@@ -1946,7 +1949,7 @@ void SigSession::set_stop_scale(float scale)
 
   int SigSession::get_device_work_mode()
   {
-      return ds_get_selected_device_index()
+      return ds_get_actived_device_mode();
   }
 
 } // namespace pv
diff --git a/DSView/pv/sigsession.h b/DSView/pv/sigsession.h
index 85605820..00a0f407 100644
--- a/DSView/pv/sigsession.h
+++ b/DSView/pv/sigsession.h
@@ -310,6 +310,7 @@ private:
     void feed_timeout();
     void repeat_update(); 
 
+
 private:
     /**
      * Attempts to autodetect the format. Failing that
@@ -332,6 +333,8 @@ private:
 	void data_feed_in(const struct sr_dev_inst *sdi,
 		        const struct sr_datafeed_packet *packet);
 
+    void get_device_list(std::vector<struct ds_device_info> &devices);
+
 	static void data_feed_callback(const struct sr_dev_inst *sdi,
 		        const struct sr_datafeed_packet *packet);
 
diff --git a/DSView/pv/toolbars/logobar.cpp b/DSView/pv/toolbars/logobar.cpp
index 3617c17d..48ff6271 100644
--- a/DSView/pv/toolbars/logobar.cpp
+++ b/DSView/pv/toolbars/logobar.cpp
@@ -28,11 +28,18 @@
 #include <QUrl>
 #include <QApplication>
 #include <assert.h>
+#include <QComboBox>
+#include <QFormLayout>
+#include <QWidget>
+#include <QCheckBox>
 
 #include "logobar.h"
 #include "../dialogs/about.h"
 #include "../dialogs/dsmessagebox.h"
 #include "../config/appconfig.h"
+#include "../dialogs/dsdialog.h"
+#include "../appcontrol.h"
+#include "../log.h"
 
 namespace pv {
 namespace toolbars {
@@ -76,6 +83,7 @@ LogoBar::LogoBar(SigSession *session, QWidget *parent) :
     _logo_button.addAction(_issue);   
 
     _update = new QAction(this);
+    _log = new QAction(this);
 
     _menu = new QMenu(this);
     _menu->addMenu(_language);
@@ -83,6 +91,7 @@ LogoBar::LogoBar(SigSession *session, QWidget *parent) :
     _menu->addAction(_manual);
     _menu->addAction(_issue);
     _menu->addAction(_update);
+    _menu->addAction(_log);
     _logo_button.setMenu(_menu);
 
     _logo_button.setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
@@ -104,6 +113,7 @@ LogoBar::LogoBar(SigSession *session, QWidget *parent) :
     connect(_manual, SIGNAL(triggered()), this, SIGNAL(sig_open_doc()));
     connect(_issue, SIGNAL(triggered()), this, SLOT(on_actionIssue_triggered()));
     connect(_update, SIGNAL(triggered()), this, SLOT(on_action_update()));
+    connect(_log, SIGNAL(triggered()), this, SLOT(on_action_setting_log()));
 }
 
 void LogoBar::changeEvent(QEvent *event)
@@ -125,6 +135,7 @@ void LogoBar::retranslateUi()
     _manual->setText(tr("&Manual"));
     _issue->setText(tr("&Bug Report"));
     _update->setText(tr("&Update"));
+    _log->setText(tr("L&og Options"));
 
     AppConfig &app = AppConfig::Instance(); 
     if (app._frameOptions.language == LAN_CN)
@@ -141,6 +152,7 @@ void LogoBar::reStyle()
     _manual->setIcon(QIcon(iconPath+"/manual.svg"));
     _issue->setIcon(QIcon(iconPath+"/bug.svg"));
     _update->setIcon(QIcon(iconPath+"/update.svg"));
+    _log->setIcon(QIcon(iconPath+"/file.svg"));
 
     if (_connected)
         _logo_button.setIcon(QIcon(iconPath+"/logo_color.svg"));
@@ -226,5 +238,53 @@ void LogoBar::enable_toggle(bool enable)
     _logo_button.setDisabled(!enable);
 }
 
+void LogoBar::on_action_setting_log()
+{   
+    AppConfig &app = AppConfig::Instance(); 
+    auto *topWind = AppControl::Instance()->GetTopWindow();
+    dialogs::DSDialog dlg(topWind, false, true);
+    dlg.setTitle(tr("Log Options"));
+    dlg.setMinimumSize(260, 120);
+    QWidget *panel = new QWidget(&dlg);
+    dlg.layout()->addWidget(panel);
+    panel->setMinimumSize(250, 110);
+    QFormLayout *lay = new QFormLayout();
+    panel->setLayout(lay);
+    lay->setVerticalSpacing(15);
+ 
+    QComboBox *cbBox = new QComboBox();
+    cbBox->setMinimumWidth(40);
+    lay->addRow(tr("Log Level"), cbBox);
+
+    for (int i=0; i<=5; i++){
+        cbBox->addItem(QString::number(i));
+    }
+    cbBox->setCurrentIndex(app._appOptions.logLevel);
+
+    QCheckBox *ckBox = new QCheckBox();
+    ckBox->setChecked(app._appOptions.ableSaveLog);
+    lay->addRow(tr("Save To File"), ckBox);
+
+    dlg.exec();
+
+    if (dlg.IsClickYes()){
+        bool ableSave = ckBox->isChecked();
+        int level = cbBox->currentIndex();
+
+        if (ableSave != app._appOptions.ableSaveLog || level != app._appOptions.logLevel){
+            app._appOptions.ableSaveLog = ableSave;
+            app._appOptions.logLevel = level;
+            app.SaveApp();
+
+            dsv_log_level(level);
+            
+            if (ableSave)
+                dsv_log_enalbe_logfile(false);
+            else
+                dsv_remove_log_file();
+        }
+    }  
+}
+
 } // namespace toolbars
 } // namespace pv
diff --git a/DSView/pv/toolbars/logobar.h b/DSView/pv/toolbars/logobar.h
index 8a244b4b..2a9ee401 100644
--- a/DSView/pv/toolbars/logobar.h
+++ b/DSView/pv/toolbars/logobar.h
@@ -75,6 +75,7 @@ private slots:
     void on_actionManual_triggered();
     void on_actionIssue_triggered();
     void on_action_update();
+    void on_action_setting_log();
 
 private:
     bool _enable;
@@ -93,6 +94,7 @@ private:
     QAction *_manual;
     QAction *_issue;
     QAction *_update;
+    QAction *_log;
 
     IMainForm *_mainForm;
 };
diff --git a/DSView/pv/utility/path.cpp b/DSView/pv/utility/path.cpp
index 602563d1..44dcc2b7 100644
--- a/DSView/pv/utility/path.cpp
+++ b/DSView/pv/utility/path.cpp
@@ -20,6 +20,9 @@
  */
 
 #include "path.h"
+#ifdef _WIN32
+#include <QTextCodec>
+#endif
 
 namespace pv{
 namespace path{
@@ -38,5 +41,20 @@ namespace path{
         }
         return path;
     }
+
+    std::string ToUnicodePath(QString path)
+    {
+        std::string str;
+
+#ifdef _WIN32
+        QTextCodec *codec = QTextCodec::codecForName("System");
+        QByteArray str_tmp = codec->fromUnicode(path);
+        str = str_tmp.data();
+#else
+        str = path.toUtf8().data();
+#endif
+
+        return str;
+    }
 }
 }
\ No newline at end of file
diff --git a/DSView/pv/utility/path.h b/DSView/pv/utility/path.h
index 7d6e40a7..f5841f29 100644
--- a/DSView/pv/utility/path.h
+++ b/DSView/pv/utility/path.h
@@ -30,6 +30,8 @@ namespace path{
     std::string ConvertPath(QString fileName);
 
     QString GetDirectoryName(QString path);
+
+    std::string ToUnicodePath(QString path);
 }
 }
  
diff --git a/common/log/xlog.c b/common/log/xlog.c
index 8093840a..f28ec57e 100644
--- a/common/log/xlog.c
+++ b/common/log/xlog.c
@@ -249,7 +249,7 @@ XLOG_API int xlog_add_receiver(xlog_context* ctx, xlog_receive_callback rev, int
  * 	append a log data receiver, return 0 if success.
  * 	the log data will be writed to file.
  */
-XLOG_API int xlog_add_receiver_from_file(xlog_context* ctx, const char *file_path, int *out_index)
+XLOG_API int xlog_add_receiver_from_file(xlog_context* ctx, const char *file_path, int *out_index, int bAppend)
 {
     int i;
     FILE *fh = NULL;
@@ -275,7 +275,11 @@ XLOG_API int xlog_add_receiver_from_file(xlog_context* ctx, const char *file_pat
         return -1;
     }
 
-    fh = fopen(file_path, "a+");
+    if (bAppend)
+        fh = fopen(file_path, "a+");
+    else
+        fh = fopen(file_path, "w+");
+
     if (fh == NULL){
         strcpy(ctx->_error, "open file error");
         pthread_mutex_unlock(&ctx->_mutext);
diff --git a/common/log/xlog.h b/common/log/xlog.h
index 2ecd170c..8d02fca0 100644
--- a/common/log/xlog.h
+++ b/common/log/xlog.h
@@ -90,7 +90,7 @@ XLOG_API int xlog_add_receiver(xlog_context* ctx, xlog_receive_callback rev, int
  * 	append a log data receiver, return 0 if success.
  * 	the log data will be writed to file.
  */
-XLOG_API int xlog_add_receiver_from_file(xlog_context* ctx, const char *file_path, int *out_index);
+XLOG_API int xlog_add_receiver_from_file(xlog_context* ctx, const char *file_path, int *out_index, int bAppend);
 
 /**
  * 	remove a log data receiver,return 0 if success.