diff --git a/connection.cpp b/connection.cpp
new file mode 100644
index 0000000..8cc1a7f
--- /dev/null
+++ b/connection.cpp
@@ -0,0 +1,86 @@
+/*
+***************************************************************************
+*
+* Author: Teunis van Beelen
+*
+* Copyright (C) 2015 Teunis van Beelen
+*
+* Email: teuniz@gmail.com
+*
+***************************************************************************
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+***************************************************************************
+*/
+
+
+#include "connection.h"
+
+
+int tmc_connection_type;
+
+struct tmcdev *usb_tmcdev;
+
+
+
+struct tmcdev * tmc_open_usb(const char *device)
+{
+  tmc_connection_type = 0;
+
+  usb_tmcdev = tmcdev_open(device);
+
+  return usb_tmcdev;
+}
+
+
+void tmc_close(void)
+{
+  if(tmc_connection_type == 0)
+  {
+    tmcdev_close(usb_tmcdev);
+
+    usb_tmcdev = NULL;
+  }
+}
+
+
+int tmc_write(const char *msg)
+{
+  if(tmc_connection_type == 0)
+  {
+    return tmcdev_write(usb_tmcdev, msg);
+  }
+
+  return -1;
+}
+
+
+int tmc_read(void)
+{
+  if(tmc_connection_type == 0)
+  {
+    return tmcdev_read(usb_tmcdev);
+  }
+
+  return -1;
+}
+
+
+
+
+
+
+
+
diff --git a/connection.h b/connection.h
new file mode 100644
index 0000000..657bfd3
--- /dev/null
+++ b/connection.h
@@ -0,0 +1,46 @@
+/*
+***************************************************************************
+*
+* Author: Teunis van Beelen
+*
+* Copyright (C) 2015 Teunis van Beelen
+*
+* Email: teuniz@gmail.com
+*
+***************************************************************************
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+***************************************************************************
+*/
+
+
+#ifndef DSR_CONNECTION_H
+#define DSR_CONNECTION_H
+
+
+#include "global.h"
+#include "tmc_dev.h"
+#include "utils.h"
+
+
+struct tmcdev * tmc_open_usb(const char *device);
+void tmc_close(void);
+int tmc_write(const char *);
+int tmc_read(void);
+
+
+
+#endif
+
diff --git a/dsremote.pro b/dsremote.pro
index 09e4cc5..6ee0f23 100644
--- a/dsremote.pro
+++ b/dsremote.pro
@@ -21,6 +21,7 @@ HEADERS += global.h
 HEADERS += mainwindow.h
 HEADERS += about_dialog.h
 HEADERS += utils.h
+HEADERS += connection.h
 HEADERS += tmc_dev.h
 HEADERS += tled.h
 HEADERS += edflib.h
@@ -35,6 +36,7 @@ SOURCES += save_data.cpp
 SOURCES += interface.cpp
 SOURCES += about_dialog.cpp
 SOURCES += utils.c
+SOURCES += connection.cpp
 SOURCES += tmc_dev.c
 SOURCES += tled.cpp
 SOURCES += edflib.c
diff --git a/global.h b/global.h
index b40c6ea..bad7b14 100644
--- a/global.h
+++ b/global.h
@@ -26,12 +26,12 @@
 */
 
 
-#ifndef DEMO_GLOBAL_H
-#define DEMO_GLOBAL_H
+#ifndef DSR_GLOBAL_H
+#define DSR_GLOBAL_H
 
 
-#define PROGRAM_NAME     "DSRemote"
-#define PROGRAM_VERSION       "0.11_1506220825"
+#define PROGRAM_NAME          "DSRemote"
+#define PROGRAM_VERSION       "0.11_1506271103"
 
 #define MAX_PATHLEN            4096
 
@@ -82,6 +82,7 @@ struct waveform_preamble
 struct device_settings
 {
   int connected;
+  int connectiontype;           // 0=USB, 1=LAN
   char modelname[128];
   char serialnr[128];
   char softwvers[128];
diff --git a/interface.cpp b/interface.cpp
index 85a4387..1d108ce 100644
--- a/interface.cpp
+++ b/interface.cpp
@@ -181,7 +181,7 @@ void UI_Mainwindow::navDialReleased()
 
     sprintf(str, ":TRIG:HOLD %e", devparms.triggerholdoff);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else if(devparms.timebasedelayenable)
     {
@@ -195,7 +195,7 @@ void UI_Mainwindow::navDialReleased()
 
       sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
     }
 
   adjDialFunc = ADJ_DIAL_FUNC_NONE;
@@ -416,7 +416,7 @@ void UI_Mainwindow::trigAdjustDialChanged(int new_pos)
 
   sprintf(str, ":TRIG:EDG:LEV %e", devparms.triggeredgelevel[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   old_pos = new_pos;
 
@@ -548,7 +548,7 @@ void UI_Mainwindow::horScaleDialChanged(int new_pos)
 
     sprintf(str, ":TIM:DEL:SCAL %e", devparms.timebasedelayscale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     old_pos = new_pos;
   }
@@ -624,7 +624,7 @@ void UI_Mainwindow::horScaleDialChanged(int new_pos)
 
     sprintf(str, ":TIM:SCAL %e", devparms.timebasescale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     old_pos = new_pos;
   }
@@ -716,7 +716,7 @@ void UI_Mainwindow::horPosDialChanged(int new_pos)
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     old_pos = new_pos;
   }
@@ -759,7 +759,7 @@ void UI_Mainwindow::horPosDialChanged(int new_pos)
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     old_pos = new_pos;
   }
@@ -859,7 +859,7 @@ void UI_Mainwindow::vertOffsetDialChanged(int new_pos)
 
   sprintf(str, ":CHAN%i:OFFS %e", chn + 1, devparms.chanoffset[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   old_pos = new_pos;
 
@@ -985,7 +985,7 @@ void UI_Mainwindow::vertScaleDialChanged(int new_pos)
 
   sprintf(str, ":CHAN%i:SCAL %e", chn + 1, devparms.chanscale[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   old_pos = new_pos;
 
@@ -1118,13 +1118,13 @@ void UI_Mainwindow::set_memdepth(int mdepth)
   {
     statusLabel->setText("Memory depth: auto");
 
-    tmcdev_write(device, ":ACQ:MDEP AUTO");
+    tmc_write(":ACQ:MDEP AUTO");
 
     devparms.timebaseoffset = 0;
 
     usleep(20000);
 
-    tmcdev_write(device, ":TIM:OFFS 0");
+    tmc_write(":TIM:OFFS 0");
 
     return;
   }
@@ -1137,13 +1137,13 @@ void UI_Mainwindow::set_memdepth(int mdepth)
 
   sprintf(str, ":ACQ:MDEP %i", mdepth);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   devparms.timebaseoffset = 0;
 
   usleep(20000);
 
-  tmcdev_write(device, ":TIM:OFFS 0");
+  tmc_write(":TIM:OFFS 0");
 }
 
 
@@ -1314,7 +1314,7 @@ void UI_Mainwindow::set_acq_normal()
 
   statusLabel->setText("Acquire: normal");
 
-  tmcdev_write(device, ":ACQ:TYPE NORM");
+  tmc_write(":ACQ:TYPE NORM");
 }
 
 
@@ -1329,7 +1329,7 @@ void UI_Mainwindow::set_acq_peak()
 
   statusLabel->setText("Acquire: peak");
 
-  tmcdev_write(device, ":ACQ:TYPE PEAK");
+  tmc_write(":ACQ:TYPE PEAK");
 }
 
 
@@ -1344,7 +1344,7 @@ void UI_Mainwindow::set_acq_hres()
 
   statusLabel->setText("Acquire: high resolution");
 
-  tmcdev_write(device, ":ACQ:TYPE HRES");
+  tmc_write(":ACQ:TYPE HRES");
 }
 
 
@@ -1367,7 +1367,7 @@ void UI_Mainwindow::set_acq_average()
 
   statusLabel->setText("Acquire: average");
 
-  tmcdev_write(device, ":ACQ:TYPE AVER");
+  tmc_write(":ACQ:TYPE AVER");
 }
 
 
@@ -1436,7 +1436,7 @@ void UI_Mainwindow::set_grid_type_vectors()
 
   statusLabel->setText("Display type: vectors");
 
-  tmcdev_write(device, ":DISP:TYPE VECT");
+  tmc_write(":DISP:TYPE VECT");
 }
 
 
@@ -1451,7 +1451,7 @@ void UI_Mainwindow::set_grid_type_dots()
 
   statusLabel->setText("Display type: dots");
 
-  tmcdev_write(device, ":DISP:TYPE DOTS");
+  tmc_write(":DISP:TYPE DOTS");
 }
 
 
@@ -1466,7 +1466,7 @@ void UI_Mainwindow::set_grid_full()
 
   statusLabel->setText("Display grid: full");
 
-  tmcdev_write(device, ":DISP:GRID FULL");
+  tmc_write(":DISP:GRID FULL");
 }
 
 
@@ -1481,7 +1481,7 @@ void UI_Mainwindow::set_grid_half()
 
   statusLabel->setText("Display grid: half");
 
-  tmcdev_write(device, ":DISP:GRID HALF");
+  tmc_write(":DISP:GRID HALF");
 }
 
 
@@ -1496,7 +1496,7 @@ void UI_Mainwindow::set_grid_none()
 
   statusLabel->setText("Display grid: none");
 
-  tmcdev_write(device, ":DISP:GRID NONE");
+  tmc_write(":DISP:GRID NONE");
 }
 
 
@@ -1504,7 +1504,7 @@ void UI_Mainwindow::set_grading_min()
 {
   statusLabel->setText("Display grading: Minimum");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME MIN");
+  tmc_write(":DISP:GRAD:TIME MIN");
 }
 
 
@@ -1512,7 +1512,7 @@ void UI_Mainwindow::set_grading_005()
 {
   statusLabel->setText("Display grading: 0.05 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 0.05");
+  tmc_write(":DISP:GRAD:TIME 0.05");
 }
 
 
@@ -1520,7 +1520,7 @@ void UI_Mainwindow::set_grading_01()
 {
   statusLabel->setText("Display grading: 0.1 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 0.1");
+  tmc_write(":DISP:GRAD:TIME 0.1");
 }
 
 
@@ -1528,7 +1528,7 @@ void UI_Mainwindow::set_grading_02()
 {
   statusLabel->setText("Display grading: 0.2 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 0.2");
+  tmc_write(":DISP:GRAD:TIME 0.2");
 }
 
 
@@ -1536,7 +1536,7 @@ void UI_Mainwindow::set_grading_05()
 {
   statusLabel->setText("Display grading: 0.5 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 0.5");
+  tmc_write(":DISP:GRAD:TIME 0.5");
 }
 
 
@@ -1544,7 +1544,7 @@ void UI_Mainwindow::set_grading_1()
 {
   statusLabel->setText("Display grading: 1 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 1");
+  tmc_write(":DISP:GRAD:TIME 1");
 }
 
 
@@ -1552,7 +1552,7 @@ void UI_Mainwindow::set_grading_2()
 {
   statusLabel->setText("Display grading: 2 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 2");
+  tmc_write(":DISP:GRAD:TIME 2");
 }
 
 
@@ -1560,7 +1560,7 @@ void UI_Mainwindow::set_grading_5()
 {
   statusLabel->setText("Display grading: 5 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 5");
+  tmc_write(":DISP:GRAD:TIME 5");
 }
 
 
@@ -1568,7 +1568,7 @@ void UI_Mainwindow::set_grading_10()
 {
   statusLabel->setText("Display grading: 10 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 10");
+  tmc_write(":DISP:GRAD:TIME 10");
 }
 
 
@@ -1576,7 +1576,7 @@ void UI_Mainwindow::set_grading_20()
 {
   statusLabel->setText("Display grading: 20 Sec.");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME 20");
+  tmc_write(":DISP:GRAD:TIME 20");
 }
 
 
@@ -1584,7 +1584,7 @@ void UI_Mainwindow::set_grading_inf()
 {
   statusLabel->setText("Display grading: Infinite");
 
-  tmcdev_write(device, ":DISP:GRAD:TIME INF");
+  tmc_write(":DISP:GRAD:TIME INF");
 }
 
 
@@ -1654,7 +1654,7 @@ void UI_Mainwindow::vertScaleDialClicked(QPoint)
 
     sprintf(str, ":CHAN%i:VERN 0", chn + 1);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -1666,7 +1666,7 @@ void UI_Mainwindow::vertScaleDialClicked(QPoint)
 
     sprintf(str, ":CHAN%i:VERN 1", chn + 1);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 }
 
@@ -1681,7 +1681,7 @@ void UI_Mainwindow::ch1ButtonClicked()
 
       statusLabel->setText("Channel 1 off");
 
-      tmcdev_write(device, ":CHAN1:DISP 0");
+      tmc_write(":CHAN1:DISP 0");
 
       ch1Button->setStyleSheet(def_stylesh);
 
@@ -1708,7 +1708,7 @@ void UI_Mainwindow::ch1ButtonClicked()
 
     statusLabel->setText("Channel 1 on");
 
-    tmcdev_write(device, ":CHAN1:DISP 1");
+    tmc_write(":CHAN1:DISP 1");
 
     ch1Button->setStyleSheet("background: #FFFF33;");
 
@@ -1727,7 +1727,7 @@ void UI_Mainwindow::ch2ButtonClicked()
 
       statusLabel->setText("Channel 2 off");
 
-      tmcdev_write(device, ":CHAN2:DISP 0");
+      tmc_write(":CHAN2:DISP 0");
 
       ch2Button->setStyleSheet(def_stylesh);
 
@@ -1754,7 +1754,7 @@ void UI_Mainwindow::ch2ButtonClicked()
 
     statusLabel->setText("Channel 2 on");
 
-    tmcdev_write(device, ":CHAN2:DISP 1");
+    tmc_write(":CHAN2:DISP 1");
 
     ch2Button->setStyleSheet("background: #33FFFF;");
 
@@ -1773,7 +1773,7 @@ void UI_Mainwindow::ch3ButtonClicked()
 
       statusLabel->setText("Channel 3 off");
 
-      tmcdev_write(device, ":CHAN3:DISP 0");
+      tmc_write(":CHAN3:DISP 0");
 
       ch3Button->setStyleSheet(def_stylesh);
 
@@ -1800,7 +1800,7 @@ void UI_Mainwindow::ch3ButtonClicked()
 
     statusLabel->setText("Channel 3 on");
 
-    tmcdev_write(device, ":CHAN3:DISP 1");
+    tmc_write(":CHAN3:DISP 1");
 
     ch3Button->setStyleSheet("background: #FF33FF;");
 
@@ -1819,7 +1819,7 @@ void UI_Mainwindow::ch4ButtonClicked()
 
       statusLabel->setText("Channel 4 off");
 
-      tmcdev_write(device, ":CHAN4:DISP 0");
+      tmc_write(":CHAN4:DISP 0");
 
       ch4Button->setStyleSheet(def_stylesh);
 
@@ -1846,7 +1846,7 @@ void UI_Mainwindow::ch4ButtonClicked()
 
     statusLabel->setText("Channel 4 on");
 
-    tmcdev_write(device, ":CHAN4:DISP 1");
+    tmc_write(":CHAN4:DISP 1");
 
     ch4Button->setStyleSheet("background: #0066CC;");
 
@@ -1900,7 +1900,7 @@ void UI_Mainwindow::chan_coupling_ac()
 
   sprintf(str, ":CHAN%i:COUP AC", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -1916,7 +1916,7 @@ void UI_Mainwindow::chan_coupling_dc()
 
   sprintf(str, ":CHAN%i:COUP DC", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -1932,7 +1932,7 @@ void UI_Mainwindow::chan_coupling_gnd()
 
   sprintf(str, ":CHAN%i:COUP GND", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -1948,7 +1948,7 @@ void UI_Mainwindow::chan_bwl_off()
 
   sprintf(str, ":CHAN%i:BWL OFF", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -1964,7 +1964,7 @@ void UI_Mainwindow::chan_bwl_20()
 
   sprintf(str, ":CHAN%i:BWL 20M", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -1980,7 +1980,7 @@ void UI_Mainwindow::chan_bwl_250()
 
   sprintf(str, ":CHAN%i:BWL 250M", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -2001,7 +2001,7 @@ void UI_Mainwindow::chan_invert_on()
 
   sprintf(str, ":CHAN%i:INV 1", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -2022,7 +2022,7 @@ void UI_Mainwindow::chan_invert_off()
 
   sprintf(str, ":CHAN%i:INV 0", devparms.activechannel + 1);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -2056,7 +2056,7 @@ void UI_Mainwindow::vertOffsetDialClicked(QPoint)
 
   sprintf(str, ":CHAN%i:OFFS %e", chn + 1, devparms.chanoffset[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
@@ -2064,7 +2064,7 @@ void UI_Mainwindow::clearButtonClicked()
 {
   statusLabel->setText("Display cleared");
 
-  tmcdev_write(device, ":DISP:CLE");
+  tmc_write(":DISP:CLE");
 }
 
 
@@ -2079,7 +2079,7 @@ void UI_Mainwindow::autoButtonClicked()
 
   statusLabel->setText("Auto settings");
 
-  tmcdev_write(device, ":AUT");
+  tmc_write(":AUT");
 
   qApp->processEvents();
 
@@ -2101,13 +2101,13 @@ void UI_Mainwindow::runButtonClicked()
   {
     statusLabel->setText("Trigger: run");
 
-    tmcdev_write(device, ":RUN");
+    tmc_write(":RUN");
   }
   else
   {
     statusLabel->setText("Trigger: stop");
 
-    tmcdev_write(device, ":STOP");
+    tmc_write(":STOP");
   }
 }
 
@@ -2116,7 +2116,7 @@ void UI_Mainwindow::singleButtonClicked()
 {
   statusLabel->setText("Trigger: single");
 
-  tmcdev_write(device, ":SING");
+  tmc_write(":SING");
 }
 
 
@@ -2165,7 +2165,7 @@ void UI_Mainwindow::horizontal_delayed_on()
 
   statusLabel->setText("Delayed timebase enabled");
 
-  tmcdev_write(device, ":TIM:DEL:ENAB 1");
+  tmc_write(":TIM:DEL:ENAB 1");
 
   devparms.timebasedelayoffset = devparms.timebaseoffset;
 }
@@ -2182,7 +2182,7 @@ void UI_Mainwindow::horizontal_delayed_off()
 
   statusLabel->setText("Delayed timebase disabled");
 
-  tmcdev_write(device, ":TIM:DEL:ENAB 0");
+  tmc_write(":TIM:DEL:ENAB 0");
 }
 
 
@@ -2194,7 +2194,7 @@ void UI_Mainwindow::horizontal_delayed_toggle()
 
     statusLabel->setText("Delayed timebase disabled");
 
-    tmcdev_write(device, ":TIM:DEL:ENAB 0");
+    tmc_write(":TIM:DEL:ENAB 0");
   }
   else
   {
@@ -2204,17 +2204,17 @@ void UI_Mainwindow::horizontal_delayed_toggle()
 
     statusLabel->setText("Delayed timebase enabled");
 
-    tmcdev_write(device, ":TIM:DEL:ENAB 1");
+    tmc_write(":TIM:DEL:ENAB 1");
 
-    tmcdev_write(device, ":TIM:DEL:OFFS?");
+    tmc_write(":TIM:DEL:OFFS?");
 
-    tmcdev_read(device);
+    tmc_read();
 
     devparms.timebasedelayoffset = atof(device->buf);
 
-    tmcdev_write(device, ":TIM:DEL:SCAL?");
+    tmc_write(":TIM:DEL:SCAL?");
 
-    tmcdev_read(device);
+    tmc_read();
 
     devparms.timebasedelayscale = atof(device->buf);
 
@@ -2241,7 +2241,7 @@ void UI_Mainwindow::horPosDialClicked(QPoint)
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -2257,7 +2257,7 @@ void UI_Mainwindow::horPosDialClicked(QPoint)
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 }
 
@@ -2301,7 +2301,7 @@ void UI_Mainwindow::counter_off()
 
   statusLabel->setText("Freq. counter off");
 
-  tmcdev_write(device, ":MEAS:COUN:SOUR OFF");
+  tmc_write(":MEAS:COUN:SOUR OFF");
 }
 
 
@@ -2311,7 +2311,7 @@ void UI_Mainwindow::counter_ch1()
 
   statusLabel->setText("Freq. counter channel 1");
 
-  tmcdev_write(device, ":MEAS:COUN:SOUR CHAN1");
+  tmc_write(":MEAS:COUN:SOUR CHAN1");
 }
 
 
@@ -2321,7 +2321,7 @@ void UI_Mainwindow::counter_ch2()
 
   statusLabel->setText("Freq. counter channel 2");
 
-  tmcdev_write(device, ":MEAS:COUN:SOUR CHAN2");
+  tmc_write(":MEAS:COUN:SOUR CHAN2");
 }
 
 
@@ -2331,7 +2331,7 @@ void UI_Mainwindow::counter_ch3()
 
   statusLabel->setText("Freq. counter channel 3");
 
-  tmcdev_write(device, ":MEAS:COUN:SOUR CHAN3");
+  tmc_write(":MEAS:COUN:SOUR CHAN3");
 }
 
 
@@ -2341,7 +2341,7 @@ void UI_Mainwindow::counter_ch4()
 
   statusLabel->setText("Freq. counter channel 4");
 
-  tmcdev_write(device, ":MEAS:COUN:SOUR CHAN4");
+  tmc_write(":MEAS:COUN:SOUR CHAN4");
 }
 
 
@@ -2356,17 +2356,17 @@ void UI_Mainwindow::trigModeButtonClicked()
     case 0: trigModeAutoLed->setValue(true);
             trigModeSingLed->setValue(false);
             statusLabel->setText("Trigger auto");
-            tmcdev_write(device, ":TRIG:SWE AUTO");
+            tmc_write(":TRIG:SWE AUTO");
             break;
     case 1: trigModeNormLed->setValue(true);
             trigModeAutoLed->setValue(false);
             statusLabel->setText("Trigger norm");
-            tmcdev_write(device, ":TRIG:SWE NORM");
+            tmc_write(":TRIG:SWE NORM");
             break;
     case 2: trigModeSingLed->setValue(true);
             trigModeNormLed->setValue(false);
             statusLabel->setText("Trigger single");
-            tmcdev_write(device, ":TRIG:SWE SING");
+            tmc_write(":TRIG:SWE SING");
             break;
   }
 }
@@ -2426,7 +2426,7 @@ void UI_Mainwindow::trigger_source_ch1()
 
   statusLabel->setText("Trigger source channel 1");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR CHAN1");
+  tmc_write(":TRIG:EDG:SOUR CHAN1");
 }
 
 
@@ -2436,7 +2436,7 @@ void UI_Mainwindow::trigger_source_ch2()
 
   statusLabel->setText("Trigger source channel 2");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR CHAN2");
+  tmc_write(":TRIG:EDG:SOUR CHAN2");
 }
 
 
@@ -2446,7 +2446,7 @@ void UI_Mainwindow::trigger_source_ch3()
 
   statusLabel->setText("Trigger source channel 3");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR CHAN3");
+  tmc_write(":TRIG:EDG:SOUR CHAN3");
 }
 
 
@@ -2456,7 +2456,7 @@ void UI_Mainwindow::trigger_source_ch4()
 
   statusLabel->setText("Trigger source channel 4");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR CHAN4");
+  tmc_write(":TRIG:EDG:SOUR CHAN4");
 }
 
 
@@ -2466,7 +2466,7 @@ void UI_Mainwindow::trigger_source_ext()
 
   statusLabel->setText("Trigger source extern");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR EXT");
+  tmc_write(":TRIG:EDG:SOUR EXT");
 }
 
 
@@ -2476,7 +2476,7 @@ void UI_Mainwindow::trigger_source_ext5()
 
   statusLabel->setText("Trigger source extern 5");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR EXT5");
+  tmc_write(":TRIG:EDG:SOUR EXT5");
 }
 
 
@@ -2486,7 +2486,7 @@ void UI_Mainwindow::trigger_source_acl()
 
   statusLabel->setText("Trigger source AC powerline");
 
-  tmcdev_write(device, ":TRIG:EDG:SOUR ACL");
+  tmc_write(":TRIG:EDG:SOUR ACL");
 }
 
 
@@ -2496,7 +2496,7 @@ void UI_Mainwindow::trigger_coupling_ac()
 
   statusLabel->setText("Trigger coupling AC");
 
-  tmcdev_write(device, ":TRIG:COUP AC");
+  tmc_write(":TRIG:COUP AC");
 }
 
 
@@ -2506,7 +2506,7 @@ void UI_Mainwindow::trigger_coupling_dc()
 
   statusLabel->setText("Trigger coupling DC");
 
-  tmcdev_write(device, ":TRIG:COUP DC");
+  tmc_write(":TRIG:COUP DC");
 }
 
 
@@ -2516,7 +2516,7 @@ void UI_Mainwindow::trigger_coupling_lfreject()
 
   statusLabel->setText("Trigger LF reject");
 
-  tmcdev_write(device, ":TRIG:COUP LFR");
+  tmc_write(":TRIG:COUP LFR");
 }
 
 
@@ -2526,7 +2526,7 @@ void UI_Mainwindow::trigger_coupling_hfreject()
 
   statusLabel->setText("Trigger HF reject");
 
-  tmcdev_write(device, ":TRIG:COUP HFR");
+  tmc_write(":TRIG:COUP HFR");
 }
 
 
@@ -2536,7 +2536,7 @@ void UI_Mainwindow::trigger_slope_pos()
 
   statusLabel->setText("Trigger edge positive");
 
-  tmcdev_write(device, ":TRIG:EDG:SLOP POS");
+  tmc_write(":TRIG:EDG:SLOP POS");
 }
 
 
@@ -2546,7 +2546,7 @@ void UI_Mainwindow::trigger_slope_neg()
 
   statusLabel->setText("Trigger edge negative");
 
-  tmcdev_write(device, ":TRIG:EDG:SLOP NEG");
+  tmc_write(":TRIG:EDG:SLOP NEG");
 }
 
 
@@ -2556,7 +2556,7 @@ void UI_Mainwindow::trigger_slope_rfal()
 
   statusLabel->setText("Trigger edge positive /negative");
 
-  tmcdev_write(device, ":TRIG:EDG:SLOP RFAL");
+  tmc_write(":TRIG:EDG:SLOP RFAL");
 }
 
 
@@ -2578,7 +2578,7 @@ void UI_Mainwindow::trigForceButtonClicked()
 {
   statusLabel->setText("Trigger force");
 
-  tmcdev_write(device, ":TFOR");
+  tmc_write(":TFOR");
 }
 
 
@@ -2586,13 +2586,13 @@ void UI_Mainwindow::trig50pctButtonClicked()
 {
   statusLabel->setText("Trigger 50%");
 
-  tmcdev_write(device, ":TLHA");
+  tmc_write(":TLHA");
 
   usleep(30000);
 
-  tmcdev_write(device, ":TRIG:EDG:LEV?");
+  tmc_write(":TRIG:EDG:LEV?");
 
-  tmcdev_read(device);
+  tmc_read();
 
   devparms.triggeredgelevel[devparms.triggeredgesource] = atof(device->buf);
 
@@ -2616,7 +2616,7 @@ void UI_Mainwindow::trigAdjustDialClicked(QPoint)
 
   sprintf(str, ":TRIG:EDG:LEV %e", devparms.triggeredgelevel[devparms.triggeredgesource]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 }
 
 
diff --git a/mainwindow.cpp b/mainwindow.cpp
index b5697e6..caa2bea 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -36,7 +36,7 @@
 
 void UI_Mainwindow::open_settings_dialog()
 {
-  UI_select_device_window sel_device;
+  UI_settings_window settings(this);
 }
 
 
@@ -56,29 +56,52 @@ void UI_Mainwindow::open_connection()
     return;
   }
 
-  strcpy(dev_str, settings.value("connection/device").toString().toLocal8Bit().data());
-
-  if(!strcmp(dev_str, ""))
+  if(devparms.connected)
   {
-    strcpy(dev_str, "/dev/usbtmc0");
-
-    settings.setValue("connection/device", dev_str);
+    return;
   }
 
-  device = tmcdev_open(dev_str);
-  if(device == NULL)
+  strcpy(str, settings.value("connection/type").toString().toLatin1().data());
+
+  if(!strcmp(str, "LAN"))
   {
-    sprintf(str, "Can not open device %s", dev_str);
-    goto OUT_ERROR;
+    devparms.connectiontype = 1;
+  }
+  else
+  {
+    devparms.connectiontype = 0;
   }
 
-  if(tmcdev_write(device, "*IDN?") != 5)
+  if(devparms.connectiontype == 0)  // USB
+  {
+    strcpy(dev_str, settings.value("connection/device").toString().toLocal8Bit().data());
+
+    if(!strcmp(dev_str, ""))
+    {
+      strcpy(dev_str, "/dev/usbtmc0");
+
+      settings.setValue("connection/device", dev_str);
+    }
+
+    device = tmc_open_usb(dev_str);
+    if(device == NULL)
+    {
+      sprintf(str, "Can not open device %s", dev_str);
+      goto OUT_ERROR;
+    }
+  }
+
+  if(devparms.connectiontype == 1)  // LAN
+  {
+  }
+
+  if(tmc_write("*IDN?") != 5)
   {
     sprintf(str, "Can not write to device %s", dev_str);
     goto OUT_ERROR;
   }
 
-  n = tmcdev_read(device);
+  n = tmc_read();
 
   if(n < 0)
   {
@@ -155,7 +178,7 @@ void UI_Mainwindow::open_connection()
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.setText("Unsupported device detected.");
     msgBox.setInformativeText("This software has not been tested with your device.\n"
-      "It has been tested with the DS6000 and DS1054 series only.\n"
+      "It has been tested with the DS6000 and DS1000Z series only.\n"
       "If you continue, it's likely that the program will not work correctly at some points.\n"
       "\nDo you want to continue?\n");
     msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
@@ -342,7 +365,7 @@ void UI_Mainwindow::close_connection()
 
   waveForm->clear();
 
-  tmcdev_close(device);
+  tmc_close();
 
   device = NULL;
 
@@ -360,7 +383,7 @@ void UI_Mainwindow::closeEvent(QCloseEvent *cl_event)
 
   adjdial_timer->stop();
 
-  tmcdev_close(device);
+  tmc_close();
 
   device = NULL;
 
@@ -384,13 +407,13 @@ int UI_Mainwindow::get_device_settings()
   {
     sprintf(str, ":CHAN%i:BWL?", chn + 1);
 
-    if(tmcdev_write(device, str) != 11)
+    if(tmc_write(str) != 11)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -416,13 +439,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:COUP?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -448,13 +471,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:DISP?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -507,13 +530,13 @@ int UI_Mainwindow::get_device_settings()
     {
       sprintf(str, ":CHAN%i:IMP?", chn + 1);
 
-      if(tmcdev_write(device, str) != 11)
+      if(tmc_write(str) != 11)
       {
         line = __LINE__;
         goto OUT_ERROR;
       }
 
-      if(tmcdev_read(device) < 1)
+      if(tmc_read() < 1)
       {
         line = __LINE__;
         goto OUT_ERROR;
@@ -536,13 +559,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:INV?", chn + 1);
 
-    if(tmcdev_write(device, str) != 11)
+    if(tmc_write(str) != 11)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -564,13 +587,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:OFFS?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -580,13 +603,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:PROB?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -596,13 +619,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:SCAL?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -612,13 +635,13 @@ int UI_Mainwindow::get_device_settings()
 
     sprintf(str, ":CHAN%i:VERN?", chn + 1);
 
-    if(tmcdev_write(device, str) != 12)
+    if(tmc_write(str) != 12)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -639,13 +662,13 @@ int UI_Mainwindow::get_device_settings()
       }
   }
 
-  if(tmcdev_write(device, ":TIM:OFFS?") != 10)
+  if(tmc_write(":TIM:OFFS?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -653,13 +676,13 @@ int UI_Mainwindow::get_device_settings()
 
   devparms.timebaseoffset = atof(device->buf);
 
-  if(tmcdev_write(device, ":TIM:SCAL?") != 10)
+  if(tmc_write(":TIM:SCAL?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -667,13 +690,13 @@ int UI_Mainwindow::get_device_settings()
 
   devparms.timebasescale = atof(device->buf);
 
-  if(tmcdev_write(device, ":TIM:DEL:ENAB?") != 14)
+  if(tmc_write(":TIM:DEL:ENAB?") != 14)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -693,13 +716,13 @@ int UI_Mainwindow::get_device_settings()
       goto OUT_ERROR;
     }
 
-  if(tmcdev_write(device, ":TIM:DEL:OFFS?") != 14)
+  if(tmc_write(":TIM:DEL:OFFS?") != 14)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -707,13 +730,13 @@ int UI_Mainwindow::get_device_settings()
 
   devparms.timebasedelayoffset = atof(device->buf);
 
-  if(tmcdev_write(device, ":TIM:DEL:SCAL?") != 14)
+  if(tmc_write(":TIM:DEL:SCAL?") != 14)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -723,13 +746,13 @@ int UI_Mainwindow::get_device_settings()
 
   if(devparms.modelserie != 1)
   {
-    if(tmcdev_write(device, ":TIM:HREF:MODE?") != 15)
+    if(tmc_write(":TIM:HREF:MODE?") != 15)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -753,13 +776,13 @@ int UI_Mainwindow::get_device_settings()
           goto OUT_ERROR;
         }
 
-    if(tmcdev_write(device, ":TIM:HREF:POS?") != 14)
+    if(tmc_write(":TIM:HREF:POS?") != 14)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -768,13 +791,13 @@ int UI_Mainwindow::get_device_settings()
 
   devparms.timebasehrefpos = atoi(device->buf);
 
-  if(tmcdev_write(device, ":TIM:MODE?") != 10)
+  if(tmc_write(":TIM:MODE?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -800,13 +823,13 @@ int UI_Mainwindow::get_device_settings()
 
   if(devparms.modelserie != 1)
   {
-    if(tmcdev_write(device, ":TIM:VERN?") != 10)
+    if(tmc_write(":TIM:VERN?") != 10)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -829,13 +852,13 @@ int UI_Mainwindow::get_device_settings()
 
   if((devparms.modelserie != 1) && (devparms.modelserie != 2))
   {
-    if(tmcdev_write(device, ":TIM:XY1:DISP?") != 14)
+    if(tmc_write(":TIM:XY1:DISP?") != 14)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -855,13 +878,13 @@ int UI_Mainwindow::get_device_settings()
         goto OUT_ERROR;
       }
 
-    if(tmcdev_write(device, ":TIM:XY2:DISP?") != 14)
+    if(tmc_write(":TIM:XY2:DISP?") != 14)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -882,13 +905,13 @@ int UI_Mainwindow::get_device_settings()
       }
   }
 
-  if(tmcdev_write(device, ":TRIG:COUP?") != 11)
+  if(tmc_write(":TRIG:COUP?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -916,13 +939,13 @@ int UI_Mainwindow::get_device_settings()
           goto OUT_ERROR;
         }
 
-  if(tmcdev_write(device, ":TRIG:SWE?") != 10)
+  if(tmc_write(":TRIG:SWE?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -958,13 +981,13 @@ int UI_Mainwindow::get_device_settings()
         goto OUT_ERROR;
       }
 
-  if(tmcdev_write(device, ":TRIG:MODE?") != 11)
+  if(tmc_write(":TRIG:MODE?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1016,13 +1039,13 @@ int UI_Mainwindow::get_device_settings()
                       goto OUT_ERROR;
                     }
 
-  if(tmcdev_write(device, ":TRIG:STAT?") != 11)
+  if(tmc_write(":TRIG:STAT?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1058,13 +1081,13 @@ int UI_Mainwindow::get_device_settings()
               goto OUT_ERROR;
             }
 
-  if(tmcdev_write(device, ":TRIG:EDG:SLOP?") != 15)
+  if(tmc_write(":TRIG:EDG:SLOP?") != 15)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1088,13 +1111,13 @@ int UI_Mainwindow::get_device_settings()
         goto OUT_ERROR;
       }
 
-  if(tmcdev_write(device, ":TRIG:EDG:SOUR?") != 15)
+  if(tmc_write(":TRIG:EDG:SOUR?") != 15)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1138,19 +1161,19 @@ int UI_Mainwindow::get_device_settings()
   {
     sprintf(str, ":TRIG:EDG:SOUR CHAN%i", chn + 1);
 
-    if(tmcdev_write(device, str) != 20)
+    if(tmc_write(str) != 20)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_write(device, ":TRIG:EDG:LEV?") != 14)
+    if(tmc_write(":TRIG:EDG:LEV?") != 14)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -1163,7 +1186,7 @@ int UI_Mainwindow::get_device_settings()
   {
     sprintf(str, ":TRIG:EDG:SOUR CHAN%i", devparms.triggeredgesource + 1);
 
-    if(tmcdev_write(device, str) != 20)
+    if(tmc_write(str) != 20)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -1172,7 +1195,7 @@ int UI_Mainwindow::get_device_settings()
 
   if(devparms.triggeredgesource== 4)
   {
-    if(tmcdev_write(device, ":TRIG:EDG:SOUR EXT") != 18)
+    if(tmc_write(":TRIG:EDG:SOUR EXT") != 18)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -1181,7 +1204,7 @@ int UI_Mainwindow::get_device_settings()
 
   if(devparms.triggeredgesource== 5)
   {
-    if(tmcdev_write(device, ":TRIG:EDG:SOUR EXT5") != 19)
+    if(tmc_write(":TRIG:EDG:SOUR EXT5") != 19)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -1190,20 +1213,20 @@ int UI_Mainwindow::get_device_settings()
 
   if(devparms.triggeredgesource== 6)
   {
-    if(tmcdev_write(device, ":TRIG:EDG:SOUR AC") != 17)
+    if(tmc_write(":TRIG:EDG:SOUR AC") != 17)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
   }
 
-  if(tmcdev_write(device, ":TRIG:HOLD?") != 11)
+  if(tmc_write(":TRIG:HOLD?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1243,13 +1266,13 @@ int UI_Mainwindow::get_device_settings()
     }
   }
 
-  if(tmcdev_write(device, ":ACQ:SRAT?") != 10)
+  if(tmc_write(":ACQ:SRAT?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1257,13 +1280,13 @@ int UI_Mainwindow::get_device_settings()
 
   devparms.samplerate = atof(device->buf);
 
-  if(tmcdev_write(device, ":DISP:GRID?") != 11)
+  if(tmc_write(":DISP:GRID?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1287,13 +1310,13 @@ int UI_Mainwindow::get_device_settings()
         goto OUT_ERROR;
       }
 
-  if(tmcdev_write(device, ":MEAS:COUN:SOUR?") != 16)
+  if(tmc_write(":MEAS:COUN:SOUR?") != 16)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1325,13 +1348,13 @@ int UI_Mainwindow::get_device_settings()
             goto OUT_ERROR;
           }
 
-  if(tmcdev_write(device, ":DISP:TYPE?") != 11)
+  if(tmc_write(":DISP:TYPE?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1351,13 +1374,13 @@ int UI_Mainwindow::get_device_settings()
       goto OUT_ERROR;
     }
 
-  if(tmcdev_write(device, ":ACQ:TYPE?") != 10)
+  if(tmc_write(":ACQ:TYPE?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1385,13 +1408,13 @@ int UI_Mainwindow::get_device_settings()
           goto OUT_ERROR;
         }
 
-  if(tmcdev_write(device, ":ACQ:AVER?") != 10)
+  if(tmc_write(":ACQ:AVER?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -1881,7 +1904,7 @@ void UI_Mainwindow::former_page()
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -1912,7 +1935,7 @@ void UI_Mainwindow::former_page()
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -1952,7 +1975,7 @@ void UI_Mainwindow::next_page()
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -1983,7 +2006,7 @@ void UI_Mainwindow::next_page()
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -2023,7 +2046,7 @@ void UI_Mainwindow::shift_page_left()
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -2054,7 +2077,7 @@ void UI_Mainwindow::shift_page_left()
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -2094,7 +2117,7 @@ void UI_Mainwindow::shift_page_right()
 
     sprintf(str, ":TIM:DEL:OFFS %e", devparms.timebasedelayoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -2125,7 +2148,7 @@ void UI_Mainwindow::shift_page_right()
 
     sprintf(str, ":TIM:OFFS %e", devparms.timebaseoffset);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -2186,7 +2209,7 @@ void UI_Mainwindow::zoom_in()
 
     sprintf(str, ":TIM:DEL:SCAL %e", devparms.timebasedelayscale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -2233,7 +2256,7 @@ void UI_Mainwindow::zoom_in()
 
     sprintf(str, ":TIM:SCAL %e", devparms.timebasescale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -2277,7 +2300,7 @@ void UI_Mainwindow::zoom_out()
 
     sprintf(str, ":TIM:DEL:SCAL %e", devparms.timebasedelayscale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
   else
   {
@@ -2300,7 +2323,7 @@ void UI_Mainwindow::zoom_out()
 
     sprintf(str, ":TIM:SCAL %e", devparms.timebasescale);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
   }
 
   waveForm->update();
@@ -2358,7 +2381,7 @@ void UI_Mainwindow::chan_scale_plus()
 
   sprintf(str, ":CHAN%i:SCAL %e", chn + 1, devparms.chanscale[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   waveForm->update();
 }
@@ -2422,7 +2445,7 @@ void UI_Mainwindow::chan_scale_minus()
 
   sprintf(str, ":CHAN%i:SCAL %e", chn + 1, devparms.chanscale[chn]);
 
-  tmcdev_write(device, str);
+  tmc_write(str);
 
   waveForm->update();
 }
@@ -2436,7 +2459,7 @@ void UI_Mainwindow::set_to_factory()
 
   scrn_timer->stop();
 
-  tmcdev_write(device, "*RST");
+  tmc_write("*RST");
 
   devparms.timebasescale = 1e-6;
 
@@ -2514,7 +2537,7 @@ void UI_Mainwindow::set_to_factory()
     {
       sprintf(str, ":CHAN%i:SCAL 1", i + 1);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
 
       usleep(20000);
     }
diff --git a/mainwindow.h b/mainwindow.h
index 2911ec6..bddb0fa 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -75,6 +75,7 @@
 #include "global.h"
 #include "about_dialog.h"
 #include "utils.h"
+#include "connection.h"
 #include "tmc_dev.h"
 #include "tled.h"
 #include "edflib.h"
diff --git a/mainwindow_constr.cpp b/mainwindow_constr.cpp
index df8bfc7..81af213 100644
--- a/mainwindow_constr.cpp
+++ b/mainwindow_constr.cpp
@@ -34,6 +34,8 @@ UI_Mainwindow::UI_Mainwindow()
 {
   int i;
 
+  char str[1024];
+
   setMinimumSize(1170, 630);
   setWindowTitle(PROGRAM_NAME " " PROGRAM_VERSION);
   setWindowIcon(QIcon(":/images/r.png"));
@@ -380,6 +382,17 @@ UI_Mainwindow::UI_Mainwindow()
 
   strcpy(recent_savedir, settings.value("path/savedir").toString().toLocal8Bit().data());
 
+  strcpy(str, settings.value("connection/type").toString().toLatin1().data());
+
+  if(!strcmp(str, "LAN"))
+  {
+    devparms.connectiontype = 1;
+  }
+  else
+  {
+    devparms.connectiontype = 0;
+  }
+
   adjDialFunc = ADJ_DIAL_FUNC_NONE;
   navDialFunc = NAV_DIAL_FUNC_NONE;
 
diff --git a/save_data.cpp b/save_data.cpp
index 6ac467c..5b29a0f 100644
--- a/save_data.cpp
+++ b/save_data.cpp
@@ -48,13 +48,13 @@ void UI_Mainwindow::save_screenshot()
 
   scrn_timer->stop();
 
-  tmcdev_write(device, ":DISP:DATA?");
+  tmc_write(":DISP:DATA?");
 
   QApplication::setOverrideCursor(Qt::WaitCursor);
 
   qApp->processEvents();
 
-  n = tmcdev_read(device);
+  n = tmc_read();
 
   QApplication::restoreOverrideCursor();
 
@@ -246,7 +246,7 @@ void UI_Mainwindow::save_memory_waveform()
     }
   }
 
-  tmcdev_write(device, ":STOP");
+  tmc_write(":STOP");
 
   usleep(20000);
 
@@ -261,21 +261,21 @@ void UI_Mainwindow::save_memory_waveform()
 
     sprintf(str, ":WAV:SOUR CHAN%i", chn + 1);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
-    tmcdev_write(device, ":WAV:FORM BYTE");
+    tmc_write(":WAV:FORM BYTE");
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:MODE RAW");
+    tmc_write(":WAV:MODE RAW");
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YINC?");
+    tmc_write(":WAV:YINC?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yinc[chn] = atof(device->buf);
 
@@ -287,11 +287,11 @@ void UI_Mainwindow::save_memory_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YREF?");
+    tmc_write(":WAV:YREF?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yref[chn] = atoi(device->buf);
 
@@ -303,11 +303,11 @@ void UI_Mainwindow::save_memory_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YOR?");
+    tmc_write(":WAV:YOR?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yor[chn] = atoi(device->buf);
 
@@ -323,15 +323,15 @@ void UI_Mainwindow::save_memory_waveform()
 //
 //       usleep(20000);
 //
-//       tmcdev_write(device, str);
+//       tmc_write(str);
 //
 //       usleep(20000);
 //
-//       tmcdev_write(device, ":WAV:RES");
+//       tmc_write(":WAV:RES");
 //
 //       usleep(20000);
 //
-//       tmcdev_write(device, ":WAV:BEG");
+//       tmc_write(":WAV:BEG");
 //     }
 
     empty_buf = 0;
@@ -354,7 +354,7 @@ void UI_Mainwindow::save_memory_waveform()
 
         usleep(20000);
 
-        tmcdev_write(device, str);
+        tmc_write(str);
 
         if((bytes_rcvd + SAV_MEM_BSZ) > mempnts)
         {
@@ -367,7 +367,7 @@ void UI_Mainwindow::save_memory_waveform()
 
         usleep(20000);
 
-        tmcdev_write(device, str);
+        tmc_write(str);
       }
       else
       {
@@ -375,7 +375,7 @@ void UI_Mainwindow::save_memory_waveform()
 
         usleep(20000);
 
-        tmcdev_write(device, str);
+        tmc_write(str);
 
         if((bytes_rcvd + SAV_MEM_BSZ) > mempnts)
         {
@@ -388,38 +388,38 @@ void UI_Mainwindow::save_memory_waveform()
 
         usleep(20000);
 
-        tmcdev_write(device, str);
+        tmc_write(str);
 
         usleep(20000);
 
-        tmcdev_write(device, ":WAV:RES");
+        tmc_write(":WAV:RES");
 
         usleep(20000);
 
-        tmcdev_write(device, ":WAV:BEG");
+        tmc_write(":WAV:BEG");
 
         usleep(20000);
 
-        tmcdev_write(device, ":WAV:STAT?");
+        tmc_write(":WAV:STAT?");
 
         usleep(20000);
 
-        tmcdev_read(device);
+        tmc_read();
 
         printf(":WAV:STAT?   %s\n", device->buf);
       }
 
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:DATA?");
+      tmc_write(":WAV:DATA?");
 
-      n = tmcdev_read(device);
+      n = tmc_read();
 
       if(devparms.modelserie != 1)
       {
         usleep(20000);
 
-        tmcdev_write(device, ":WAV:END");
+        tmc_write(":WAV:END");
       }
 
       if(n < 0)
@@ -481,7 +481,7 @@ void UI_Mainwindow::save_memory_waveform()
 //     {
 //       usleep(20000);
 //
-//       tmcdev_write(device, ":WAV:END");
+//       tmc_write(":WAV:END");
 //     }
 
     if(bytes_rcvd < mempnts)
@@ -504,40 +504,40 @@ void UI_Mainwindow::save_memory_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:MODE NORM");
+    tmc_write(":WAV:MODE NORM");
 
     if(devparms.modelserie == 6)
     {
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:STAR 0");
+      tmc_write(":WAV:STAR 0");
     }
     else
     {
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:STAR 1");
+      tmc_write(":WAV:STAR 1");
     }
 
     if(devparms.modelserie == 1)
     {
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:STOP 1200");
+      tmc_write(":WAV:STOP 1200");
     }
     else
     {
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:STOP 1400");
+      tmc_write(":WAV:STOP 1400");
 
       usleep(20000);
 
-      tmcdev_write(device, ":WAV:POIN 1400");
+      tmc_write(":WAV:POIN 1400");
     }
   }
 
@@ -674,28 +674,28 @@ OUT_ERROR:
 
     sprintf(str, ":WAV:SOUR CHAN%i", chn + 1);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
-    tmcdev_write(device, ":WAV:MODE NORM");
+    tmc_write(":WAV:MODE NORM");
 
     if(devparms.modelserie == 6)
     {
-      tmcdev_write(device, ":WAV:STAR 0");
+      tmc_write(":WAV:STAR 0");
     }
     else
     {
-      tmcdev_write(device, ":WAV:STAR 1");
+      tmc_write(":WAV:STAR 1");
     }
 
     if(devparms.modelserie == 1)
     {
-      tmcdev_write(device, ":WAV:STOP 1200");
+      tmc_write(":WAV:STOP 1200");
     }
     else
     {
-      tmcdev_write(device, ":WAV:STOP 1400");
+      tmc_write(":WAV:STOP 1400");
 
-      tmcdev_write(device, ":WAV:POIN 1400");
+      tmc_write(":WAV:POIN 1400");
     }
   }
 
@@ -708,9 +708,9 @@ OUT_ERROR:
 }
 
 
-//     tmcdev_write(device, ":WAV:PRE?");
+//     tmc_write(":WAV:PRE?");
 //
-//     n = tmcdev_read(device);
+//     n = tmc_read();
 //
 //     if(n < 0)
 //     {
@@ -826,23 +826,23 @@ void UI_Mainwindow::save_screen_waveform()
 
     sprintf(str, ":WAV:SOUR CHAN%i", chn + 1);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:FORM BYTE");
+    tmc_write(":WAV:FORM BYTE");
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:MODE NORM");
+    tmc_write(":WAV:MODE NORM");
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YINC?");
+    tmc_write(":WAV:YINC?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yinc[chn] = atof(device->buf);
 
@@ -854,11 +854,11 @@ void UI_Mainwindow::save_screen_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YREF?");
+    tmc_write(":WAV:YREF?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yref[chn] = atoi(device->buf);
 
@@ -870,11 +870,11 @@ void UI_Mainwindow::save_screen_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:YOR?");
+    tmc_write(":WAV:YOR?");
 
     usleep(20000);
 
-    tmcdev_read(device);
+    tmc_read();
 
     yor[chn] = atoi(device->buf);
 
@@ -886,13 +886,13 @@ void UI_Mainwindow::save_screen_waveform()
 
     usleep(20000);
 
-    tmcdev_write(device, ":WAV:DATA?");
+    tmc_write(":WAV:DATA?");
 
     QApplication::setOverrideCursor(Qt::WaitCursor);
 
     qApp->processEvents();
 
-    n = tmcdev_read(device);
+    n = tmc_read();
 
     QApplication::restoreOverrideCursor();
 
diff --git a/settings_dialog.cpp b/settings_dialog.cpp
index 5e63b29..495b1ae 100644
--- a/settings_dialog.cpp
+++ b/settings_dialog.cpp
@@ -32,7 +32,7 @@
 
 
 
-UI_select_device_window::UI_select_device_window(QDialog *parnt)
+UI_settings_window::UI_settings_window(QWidget *parnt)
 {
   QSettings settings;
 
@@ -45,8 +45,24 @@ UI_select_device_window::UI_select_device_window(QDialog *parnt)
   setWindowTitle("Settings");
   setModal(true);
 
+  usbRadioButton = new QRadioButton("USB", this);
+  usbRadioButton->setAutoExclusive(true);
+  usbRadioButton->setGeometry(40, 20, 110, 25);
+  if(mainwindow->devparms.connectiontype == 0)
+  {
+    usbRadioButton->setChecked(true);
+  }
+
+  lanRadioButton = new QRadioButton("LAN", this);
+  lanRadioButton->setAutoExclusive(true);
+  lanRadioButton->setGeometry(260, 20, 110, 25);
+  if(mainwindow->devparms.connectiontype == 1)
+  {
+    lanRadioButton->setChecked(true);
+  }
+
   comboBox1 = new QComboBox(this);
-  comboBox1->setGeometry(20, 20, 110, 26);
+  comboBox1->setGeometry(20, 65, 110, 25);
   comboBox1->addItem("/dev/usbtmc0");
   comboBox1->addItem("/dev/usbtmc1");
   comboBox1->addItem("/dev/usbtmc2");
@@ -58,12 +74,24 @@ UI_select_device_window::UI_select_device_window(QDialog *parnt)
   comboBox1->addItem("/dev/usbtmc8");
   comboBox1->addItem("/dev/usbtmc9");
 
+  ipLineEdit = new QLineEdit(this);
+  ipLineEdit->setGeometry(240, 65, 110, 25);
+  ipLineEdit->setInputMask("000.000.000.000;_");
+  if(settings.contains("connection/ip"))
+  {
+    ipLineEdit->setText(settings.value("connection/ip").toString());
+  }
+  else
+  {
+    ipLineEdit->setText("192.168.001.088");
+  }
+
   applyButton = new QPushButton(this);
   applyButton->setGeometry(20, 155, 100, 25);
   applyButton->setText("Apply");
 
   cancelButton = new QPushButton(this);
-  cancelButton->setGeometry(280, 155, 100, 25);
+  cancelButton->setGeometry(240, 155, 100, 25);
   cancelButton->setText("Cancel");
 
   strcpy(dev_str, settings.value("connection/device").toString().toLocal8Bit().data());
@@ -75,28 +103,52 @@ UI_select_device_window::UI_select_device_window(QDialog *parnt)
 
   comboBox1->setCurrentIndex(dev_str[11] - '0');
 
-  QObject::connect(applyButton,  SIGNAL(clicked()), this, SLOT(applyButtonClicked()));
-  QObject::connect(cancelButton, SIGNAL(clicked()), this, SLOT(close()));
+  QObject::connect(applyButton,    SIGNAL(clicked()),     this, SLOT(applyButtonClicked()));
+  QObject::connect(cancelButton,   SIGNAL(clicked()),     this, SLOT(close()));
 
   exec();
 }
 
 
-
-void UI_select_device_window::applyButtonClicked()
+void UI_settings_window::applyButtonClicked()
 {
   char dev_str[128];
 
   QSettings settings;
 
+  if(mainwindow->devparms.connected)
+  {
+    close();
+  }
+
   strcpy(dev_str, "/dev/usbtmc0");
 
   dev_str[11] = '0' + comboBox1->currentIndex();
 
+  if(usbRadioButton->isChecked() == true)
+  {
+    settings.setValue("connection/type", "USB");
+
+    mainwindow->devparms.connectiontype = 0;
+  }
+  else
+  {
+    settings.setValue("connection/type", "LAN");
+
+    mainwindow->devparms.connectiontype = 1;
+  }
+
   settings.setValue("connection/device", dev_str);
 
+  settings.setValue("connection/ip", ipLineEdit->text());
+
   close();
 }
 
 
 
+
+
+
+
+
diff --git a/settings_dialog.h b/settings_dialog.h
index 2379392..b091976 100644
--- a/settings_dialog.h
+++ b/settings_dialog.h
@@ -40,6 +40,8 @@
 #include <QPushButton>
 #include <QComboBox>
 #include <QSettings>
+#include <QLineEdit>
+#include <QRadioButton>
 
 #include "mainwindow.h"
 #include "global.h"
@@ -48,21 +50,26 @@
 class UI_Mainwindow;
 
 
-class UI_select_device_window : public QDialog
+class UI_settings_window : public QDialog
 {
   Q_OBJECT
 
 public:
 
-  UI_select_device_window(QDialog *parent=0);
+  UI_settings_window(QWidget *parent=0);
 
 private:
 
 QPushButton  *cancelButton,
              *applyButton;
 
+QRadioButton *usbRadioButton,
+             *lanRadioButton;
+
 QComboBox    *comboBox1;
 
+QLineEdit    *ipLineEdit;
+
 UI_Mainwindow *mainwindow;
 
 private slots:
diff --git a/signalcurve.cpp b/signalcurve.cpp
index e47cc30..8798c4d 100644
--- a/signalcurve.cpp
+++ b/signalcurve.cpp
@@ -1394,7 +1394,7 @@ void SignalCurve::mouseReleaseEvent(QMouseEvent *release_event)
 
       sprintf(str, ":TIM:DEL:OFFS %e", devparms->timebasedelayoffset);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
     }
     else
     {
@@ -1414,7 +1414,7 @@ void SignalCurve::mouseReleaseEvent(QMouseEvent *release_event)
 
       sprintf(str, ":TIM:OFFS %e", devparms->timebaseoffset);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
     }
   }
   else if(trig_level_arrow_moving)
@@ -1458,7 +1458,7 @@ void SignalCurve::mouseReleaseEvent(QMouseEvent *release_event)
 
       if(device != NULL)
       {
-        tmcdev_write(device, str);
+        tmc_write(str);
       }
 
       trig_line_timer->start(1000);
@@ -1507,7 +1507,7 @@ void SignalCurve::mouseReleaseEvent(QMouseEvent *release_event)
 
           if(device != NULL)
           {
-            tmcdev_write(device, str);
+            tmc_write(str);
           }
 
           devparms->activechannel = chn;
diff --git a/signalcurve.h b/signalcurve.h
index 8c32158..64a7a5f 100644
--- a/signalcurve.h
+++ b/signalcurve.h
@@ -50,6 +50,7 @@
 
 #include "mainwindow.h"
 #include "global.h"
+#include "connection.h"
 #include "tmc_dev.h"
 #include "utils.h"
 
diff --git a/timer_handlers.cpp b/timer_handlers.cpp
index 05c5bf3..be86517 100644
--- a/timer_handlers.cpp
+++ b/timer_handlers.cpp
@@ -91,13 +91,13 @@ void UI_Mainwindow::adjdial_timer_handler()
 
     sprintf(str, ":TRIG:HOLD %e", devparms.triggerholdoff);
 
-    tmcdev_write(device, str);
+    tmc_write(str);
 
     if(devparms.modelserie == 6)
     {
       usleep(20000);
 
-      tmcdev_write(device, ":CLE");
+      tmc_write(":CLE");
     }
   }
   else if(adjDialFunc == ADJ_DIAL_FUNC_ACQ_AVG)
@@ -108,7 +108,7 @@ void UI_Mainwindow::adjdial_timer_handler()
 
       sprintf(str, ":ACQ:AVER %i", devparms.acquireaverages);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
     }
 
   adjDialFunc = ADJ_DIAL_FUNC_NONE;
@@ -131,13 +131,13 @@ void UI_Mainwindow::stat_timer_handler()
 
   char str[512];
 
-  if(tmcdev_write(device, ":TRIG:STAT?") != 11)
+  if(tmc_write(":TRIG:STAT?") != 11)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -189,13 +189,13 @@ void UI_Mainwindow::stat_timer_handler()
               goto OUT_ERROR;
             }
 
-  if(tmcdev_write(device, ":TRIG:SWE?") != 10)
+  if(tmc_write(":TRIG:SWE?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -231,13 +231,13 @@ void UI_Mainwindow::stat_timer_handler()
         goto OUT_ERROR;
       }
 
-  if(tmcdev_write(device, ":ACQ:SRAT?") != 10)
+  if(tmc_write(":ACQ:SRAT?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -245,13 +245,13 @@ void UI_Mainwindow::stat_timer_handler()
 
   devparms.samplerate = atof(device->buf);
 
-  if(tmcdev_write(device, ":ACQ:MDEP?") != 10)
+  if(tmc_write(":ACQ:MDEP?") != 10)
   {
     line = __LINE__;
     goto OUT_ERROR;
   }
 
-  if(tmcdev_read(device) < 1)
+  if(tmc_read() < 1)
   {
     line = __LINE__;
     goto OUT_ERROR;
@@ -261,13 +261,13 @@ void UI_Mainwindow::stat_timer_handler()
 
   if(devparms.countersrc)
   {
-    if(tmcdev_write(device, ":MEAS:COUN:VAL?") != 15)
+    if(tmc_write(":MEAS:COUN:VAL?") != 15)
     {
       line = __LINE__;
       goto OUT_ERROR;
     }
 
-    if(tmcdev_read(device) < 1)
+    if(tmc_read() < 1)
     {
       line = __LINE__;
       goto OUT_ERROR;
@@ -335,9 +335,9 @@ void UI_Mainwindow::scrn_timer_handler()
 
 ///////////////////////////////////////////////////////////
 
-//     tmcdev_write(device, ":WAV:PRE?");
+//     tmc_write(":WAV:PRE?");
 //
-//     n = tmcdev_read(device);
+//     n = tmc_read();
 //
 //     if(n < 0)
 //     {
@@ -376,15 +376,15 @@ void UI_Mainwindow::scrn_timer_handler()
 
       sprintf(str, ":WAV:SOUR CHAN%i", i + 1);
 
-      tmcdev_write(device, str);
+      tmc_write(str);
 
-      tmcdev_write(device, ":WAV:FORM BYTE");
+      tmc_write(":WAV:FORM BYTE");
 
-      tmcdev_write(device, ":WAV:MODE NORM");
+      tmc_write(":WAV:MODE NORM");
 
-      tmcdev_write(device, ":WAV:DATA?");
+      tmc_write(":WAV:DATA?");
 
-      n = tmcdev_read(device);
+      n = tmc_read();
 
       if(n < 0)
       {