diff --git a/index.js b/index.js
index 01cf4fd..eccb202 100644
--- a/index.js
+++ b/index.js
@@ -234,13 +234,15 @@ function deleteSocket(socketOrIdx) {
 /* Delete socket from lists (sockets and ports)
    socketOrIdx is socket object or index of socket record to delete*/
   let idx = (typeof socketOrIdx === "number") ? socketOrIdx : findSocketIdx(socketOrIdx);
+//  log("Deleting socket at index " + idx, mDbug);
   if (idx > -1 && idx < sockets.length) {
     // Clear USB's knowledge of socket connection record
     if (sockets[idx].serialIdx > -1) {
+//      log("  Clearing port index " + sockets[idx].serialIdx + " reference to this socket", mDbug);
       ports[sockets[idx].serialIdx].socket = null;
       ports[sockets[idx].serialIdx].socketIdx = -1;
     }
-    // Delete socket connection record and adjust USB's later references down, if any
+    // Delete socket connection record and adjust ports' later references down, if any
     sockets.splice(idx, 1);
     ports.forEach(function(v) {if (v.socketIdx > idx) {v.socketIdx--}});
   }
@@ -268,6 +270,7 @@ function connect_ws(ws_port, url_path) {
   
     wsServer.addEventListener('request', function(req) {
       var socket = req.accept();
+//      log("Adding socket at index " + sockets.length, mDbug);
       sockets.push({socket:socket, serialIdx:-1});
       
       //Listen for ports
@@ -289,7 +292,7 @@ function connect_ws(ws_port, url_path) {
 
               // open or close the serial port for terminal/debug
           } else if (ws_msg.type === "serial-terminal") {
-            serialTerminal(socket, ws_msg.action, ws_msg.portPath, ws_msg.baudrate, ws_msg.msg); // action is "open" or "close"
+            serialTerminal(socket, ws_msg.action, ws_msg.portPath, ws_msg.baudrate, ws_msg.msg); // action is "open", "close" or "msg"
 
           // send an updated port list
           } else if (ws_msg.type === "port-list-request") {
@@ -417,7 +420,17 @@ function serialTerminal(sock, action, portPath, baudrate, msg) {
     if (conn) {conn.mode = 'none'}
   } else if (action === "msg") {
     // Serial message to send to the device
-    send(findPortId(portPath), msg);
+    // Find port connection id from portPath or socket
+    let cid = findPortId(portPath);
+    if (!cid) {
+      let sIdx = findSocketIdx(sock);
+      if (sIdx > -1) {
+         cid = (sockets[sIdx].serialIdx > -1) ? ports[sockets[sIdx].serialIdx].connId : null;
+      }
+    }
+    if (cid) {
+      send(cid, msg);
+    }
   }
 }
 
diff --git a/manifest.json b/manifest.json
index 17d441f..36d280f 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,7 +1,7 @@
 {
   "name": "BlocklyProp Launcher",
   "description": "A Chrome application that connects your Propeller-Powered Hardware to the BlocklyProp website.",
-  "version": "0.7.2",
+  "version": "0.7.4",
   "manifest_version": 2,
   "minimum_chrome_version": "45",
   
diff --git a/serial.js b/serial.js
index de54cc0..28bb2c7 100644
--- a/serial.js
+++ b/serial.js
@@ -110,9 +110,7 @@ function openPort(sock, portPath, baudrate, connMode) {
         var cid = findPortId(portPath);
         if (cid) {
             //Already open; ensure correct baudrate, socket, and connMode, then resolve.
-            changeBaudrate(cid, baudrate)
-                .then(function() {updatePortSocket(cid, sock)})
-                .then(function() {findPort(cid).mode = connMode})
+            updatePort(sock, cid, connMode, baudrate)
                 .then(function() {resolve(cid)})
                 .catch(function (e) {reject(e)});
         } else {
@@ -127,7 +125,7 @@ function openPort(sock, portPath, baudrate, connMode) {
                 function (openInfo) {
                     if (!chrome.runtime.lastError) {
                         // No error; create serial port object
-                        addPort(sock, openInfo.connectionId, connMode, portPath, baudrate);
+                        addPort(openInfo.connectionId, sock, connMode, portPath, baudrate);
                         log("Port " + portPath + " open with ID " + openInfo.connectionId, mStat);
                         resolve(openInfo.connectionId);
                     } else {
@@ -281,36 +279,20 @@ chrome.serial.onReceiveError.addListener(function(info) {
 //    log("Error: PortID "+info.connectionId+" "+info.error, mDeep);
 });
 
-function updatePortSocket(cid, newSocket) {
-    /* Update port cid's socket references
-     cid is the open port's connection identifier
-     newSocket is the new socket object*/
-    let cIdx = findPortIdx(cid);
-    if (cIdx > -1) {
-        let sIdx = (newSocket) ? findSocketIdx(newSocket) : -1;
-        if (ports[cIdx].socketIdx !== sIdx) {
-            // newSocket is different; update required
-            if (ports[cIdx].socketIdx !== -1) {
-                // Adjust existing socket's record
-                sockets[ports[cIdx].socketIdx].serialIdx = -1;
-            }
-            // Update port and socket records
-            ports[cIdx].socket = newSocket;
-            ports[cIdx].socketIdx = sIdx;
-            sockets[sIdx].serialIdx = cIdx;
-        }
-    }
-}
-
-function addPort(socket, cid, connMode, portPath, portBaudrate) {
+function addPort(cid, socket, connMode, portPath, portBaudrate) {
 // Add new serial port record
     let idx = findSocketIdx(socket);
+/*    if (idx = -1) {
+        log("Adding port at index " + ports.length, mDbug);
+    } else {
+        log("Adding port at index " + sockets.length + " referencing socket at index " + idx, mDbug);
+    }*/
     ports.push({
+        connId    : cid,
+        path      : portPath,
         socket    : socket,
         socketIdx : idx,
-        connId    : cid,
         mode      : connMode,
-        path      : portPath,
         baud      : portBaudrate,
         packet    : {}
     });
@@ -320,6 +302,39 @@ function addPort(socket, cid, connMode, portPath, portBaudrate) {
     if (idx > -1) {sockets[idx].serialIdx = ports.length-1}
 }
 
+function updatePort(socket, cid, connMode, portBaudrate) {
+// Update port attributes if necessary
+// Automatically handles special cases like baudrate changes and sockets<->ports links
+    return new Promise(function(resolve, reject) {
+        let cIdx = findPortIdx(cid);
+//        log("Updating port at index " + cIdx, mDbug);
+        if (cIdx > -1) {
+            //Update sockets<->ports links as necessary
+            let sIdx = (socket) ? findSocketIdx(socket) : -1;
+            if (ports[cIdx].socketIdx !== sIdx) {
+                // newSocket is different; update required
+//                log("  Linking to socket index " + sIdx, mDbug);
+                if (ports[cIdx].socketIdx !== -1) {
+                    // Adjust existing socket's record
+                    sockets[ports[cIdx].socketIdx].serialIdx = -1;
+                }
+                // Update port and socket records
+                ports[cIdx].socket = socket;
+                ports[cIdx].socketIdx = sIdx;
+                if (sIdx > -1) {
+                    sockets[sIdx].serialIdx = cIdx;
+                }
+            }
+            //Update connection mode
+            ports[cIdx].mode = connMode;
+            //Update baudrate
+            changeBaudrate(cid, portBaudrate)
+                .then(function (p) {resolve(p)})
+                .catch(function (e) {reject(e)});
+        }
+    })
+}
+
 function findPortId(portPath) {
     /* Return id (cid) of serial port associated with portPath
      Returns null if not found*/