diff --git a/js/SerialMonitor/PositionControlPanelView.js b/js/SerialMonitor/PositionControlPanelView.js
index c3859e32c2c9e5d0505d282d0baa9b82b9a1771e..dbe11fb94def94a3751c6d74827f0f34af179a23 100644
--- a/js/SerialMonitor/PositionControlPanelView.js
+++ b/js/SerialMonitor/PositionControlPanelView.js
@@ -40,6 +40,11 @@ define(['jquery', 'underscore', 'backbone', 'text!PositionControlPanelView.html'
             this.model.send("!");
         },
 
+        _pause: function(e){
+            e.preventDefault();
+            this.model.pauseStream();
+        },
+
         _makeTemplateJSON: function(){
             return {};
         },
diff --git a/js/cam/Cam.js b/js/cam/Cam.js
index a6563ab656354233e1206d5e65d7f745409df6d8..76e0d76fba2f9996328b2934d035f21610a1dea5 100644
--- a/js/cam/Cam.js
+++ b/js/cam/Cam.js
@@ -275,41 +275,47 @@ define(['underscore', 'three', 'backbone', 'appState', 'latticeCAM', 'threeModel
         resetSimulation: function(){
             this.set("simLineNumber", 0, {silent:true});
             appState.set("stockSimulationPlaying", false);
+            //todo isStreaming = false;
             three.stopAnimationLoop();
             lattice.showCells("cells");
         },
 
         _stockSimulation: function(){
             if (appState.get("stockSimulationPlaying")){
-                three.startAnimationLoop();
-                var currentLine = this.get("simLineNumber");
-                if (currentLine == 0) lattice.hideCells("cells");
-                var allLines = this.get("dataOut").split("\n");
-                if(currentLine<allLines.length){
-                    var self = this;
-
-                    var scale = lattice.get("scale");
-                    var scaledSettings = {
-                        scale: scale,
-                        originPosition: this.get("originPosition").clone().divideScalar(scale),
-                        stockPosition: this.get("stockPosition").clone().divideScalar(scale),
-                    };
-
-                    this.get("exporter").simulate(allLines[currentLine], this.get("assembler"),
-                        scaledSettings, function(){
-                            currentLine++;
-                            self.set("simLineNumber", currentLine);
-                            self._stockSimulation();
-                        });
-                } else {
-                    //finished simulation
-                    this.resetSimulation();
-                }
+                var currentLineNum = this.get("simLineNumber");
+                var self = this;
+                this.simulateCurrentLine(function(){
+                    currentLineNum++;
+                    self.set("simLineNumber", currentLineNum);
+                    self._stockSimulation();
+                });
             } else {
                 three.stopAnimationLoop();
                 this.get("assembler").pause();
             }
+        },
 
+        simulateCurrentLine: function(callback){
+            var lineNum = this.get("simLineNumber");
+            console.log(lineNum);
+            three.startAnimationLoop();
+            if (lineNum == 0) lattice.hideCells("cells");
+            var allLines = this.get("dataOut").split("\n");
+            if(lineNum < allLines.length){
+
+                var scale = lattice.get("scale");
+                var scaledSettings = {
+                    scale: scale,
+                    originPosition: this.get("originPosition").clone().divideScalar(scale),
+                    stockPosition: this.get("stockPosition").clone().divideScalar(scale)
+                };
+
+                this.get("exporter").simulate(allLines[lineNum], this.get("assembler"),
+                    scaledSettings, callback);
+            } else {
+                //finished simulation
+                this.resetSimulation();
+            }
         },
 
 
diff --git a/js/cam/assemblers/Assembler.js b/js/cam/assemblers/Assembler.js
index 98d6c523764de18876a1e1b33c1da58cd3bd33f0..665cef16a603e61b4ca18e3b070b6e98cae63f51 100644
--- a/js/cam/assemblers/Assembler.js
+++ b/js/cam/assemblers/Assembler.js
@@ -239,7 +239,7 @@ define(['underscore', 'appState', 'lattice', 'stlLoader', 'threeModel', 'cam', '
         function sketchyCallback(){
             totalThreads -= 1;
             if (totalThreads > 0) return;
-            callback();
+            if (callback) callback();
         }
 
         var startingPos = this.components.xAxis.getPosition().add(this.components.yAxis.getPosition().add(this.components.zAxis.getPosition()));//this.components.zAxis.getAbsolutePosition();//get position of end effector
diff --git a/js/cam/processes/GCodeExporter.js b/js/cam/processes/GCodeExporter.js
index fd5ff5bacec7181e6f203b643a47b135831487b0..b7a7869f8bbb67aa10275d0440cebe60f4d14c23 100644
--- a/js/cam/processes/GCodeExporter.js
+++ b/js/cam/processes/GCodeExporter.js
@@ -123,20 +123,24 @@ define(['underscore', 'cam', 'lattice', 'three'], function(_, cam, lattice, THRE
             var json = line.substr(1,line.length-2);
             json = JSON.parse(json);
             machine.releaseStock(json, settings);
-            return callback();
+            if (callback) callback();
+            return;
         }
         if (line[0] == "F"){//speed
             this.animationSpeed = line.split("F")[1] / settings.scale;
-            return callback();
+            if (callback) callback();
+            return;
         }
         if (line == "" || line[0] == "(" || !this._isMoveCommand(line)){
-            return callback();
+            if (callback) callback();
+            return;
         }
         if (this._isMoveCommand(line)){
             return this._simulateMove(line, this.animationSpeed, machine, settings, callback);
         } else {
             console.warn("problem parsing gcode: " + line);
-            return callback();
+            if (callback) callback();
+            return;
         }
     };
 
diff --git a/js/menus/SendMenuView.js b/js/menus/SendMenuView.js
index be5a5e9e8beab38967f9beb3b332fd8a6c004d55..ca6fe42b199a999554c8e3539fc22d8ccc4e8715 100644
--- a/js/menus/SendMenuView.js
+++ b/js/menus/SendMenuView.js
@@ -29,19 +29,16 @@ define(['jquery', 'underscore', 'menuParent', 'serialComm', 'commPlist', 'text!s
 
         _startStream: function(e){
             e.preventDefault();
-            this.model.set("stockSimulationPlaying", true);
             serialComm.startStream();
         },
 
         _pauseStream: function(e){
             e.preventDefault();
-            this.model.set("stockSimulationPlaying", false);
             serialComm.pauseStream();
         },
 
         _stopMachine: function(e){
             e.preventDefault();
-            this.model.set("stockSimulationPlaying", false);
             serialComm.stopStream();
         },
 
diff --git a/js/models/MachineState.js b/js/models/MachineState.js
index c1484ae46d20d1a1c66ee28ca2abb4a37d7f6a33..a6923937828276d40866762cd07ff28e8081b92d 100644
--- a/js/models/MachineState.js
+++ b/js/models/MachineState.js
@@ -25,7 +25,7 @@ define(['underscore', 'backbone'], function(_, Backbone){
             });
             if (data.stat !== null && data.stat !== undefined) {
                 this.set("status", data.stat);
-                if (data.stat == 1 || data.stat == 3 || data.stat == 4) this._triggerNextCommand();
+                if (this.isReadyStatus(data.stat)) this._triggerNextCommand();
             }
         },
 
@@ -36,6 +36,11 @@ define(['underscore', 'backbone'], function(_, Backbone){
             } else this.set("status", 10);
         },
 
+        isReadyStatus: function(status){
+            if (status == undefined) status = this.get("status");
+            return status == 1 || status == 3 || status == 4;
+        },
+
         _triggerNextCommand: function(){
             this.trigger("readyForNextCommand");
         },
diff --git a/js/models/SerialComm.js b/js/models/SerialComm.js
index bdf78248613b30c56fe3018d79f294dfdc225f61..ba0ff1f76b7f7c02f31150f85f8b149686ee06e9 100644
--- a/js/models/SerialComm.js
+++ b/js/models/SerialComm.js
@@ -2,7 +2,8 @@
  * Created by aghassaei on 6/17/15.
  */
 
-define(['underscore', 'backbone', 'socketio', 'machineState'], function(_, Backbone, io, machineState){
+define(['underscore', 'backbone', 'socketio', 'machineState'],
+    function(_, Backbone, io, machineState){
 
     var SerialComm = Backbone.Model.extend({
 
@@ -60,6 +61,33 @@ define(['underscore', 'backbone', 'socketio', 'machineState'], function(_, Backb
             this.socket.emit("stopStream");
         },
 
+        sendGCode: function(){
+            var self = this;
+            var machineState = this.getMachineState();
+            require(['cam'], function(cam){
+                if (machineState && machineState.isReadyStatus()){
+                    var lineNum = cam.get("simLineNumber");
+                    var allLines = cam.get("dataOut").split("\n");
+                    if (lineNum >= 0 && lineNum < allLines.length) {
+                        var line = allLines[lineNum];
+                        self.listenToOnce(machineState, "readyForNextCommand", function(){
+                            lineNum ++;
+                            cam.set("simLineNumber", lineNum);
+                            self.sendGCode();
+                        });
+                        self.send('{"gc":"' + line + '"}');
+                        cam.simulateCurrentLine();
+                    } else if (lineNum == allLines.length){
+                        cam.simulateCurrentLine();
+                        self.pauseStream();
+                    } else {
+                        console.warn("invalid line number " + lineNum);
+                    }
+
+                }
+            });
+        },
+
         refreshMachineState: function(){//when updating connection, create a new instance of machine state
             this.machineState.refresh();
         },
@@ -119,6 +147,7 @@ define(['underscore', 'backbone', 'socketio', 'machineState'], function(_, Backb
 
         socket.on('isStreaming', function(data){
             serialComm.set("isStreaming", data);
+            if (data == true) serialComm.sendGCode();
         });
 
         socket.on('portConnected', function(data){
diff --git a/node/nodeServer.js b/node/nodeServer.js
index ef7ce05315d04fe37d8fdb2abae3e9b9f8db10e1..b52be41abf6aabca2e7b07fcd4154acab6c8d1e7 100644
--- a/node/nodeServer.js
+++ b/node/nodeServer.js
@@ -171,6 +171,7 @@ io.on('connection', function(socket){
 
     function onPortOpen(name, baud){
         io.emit("portConnected", {baudRate:baud, portName:name});
+        setIsStreaming(false);
     }
 
     function onPortData(data){