diff --git a/dist/Time4Midi 0.1.0.exe b/dist/Time4Midi 0.2.0.exe
similarity index 96%
rename from dist/Time4Midi 0.1.0.exe
rename to dist/Time4Midi 0.2.0.exe
index a4b3a71..d8c3d97 100644
Binary files a/dist/Time4Midi 0.1.0.exe and b/dist/Time4Midi 0.2.0.exe differ
diff --git a/dist/builder-debug.yml b/dist/builder-debug.yml
index 721c31b..aac5826 100644
--- a/dist/builder-debug.yml
+++ b/dist/builder-debug.yml
@@ -23,4 +23,4 @@ x64:
     - JHArtworks2023_wh.png
     - package.json
 nsis:
-  script: "!include \"C:\\Projects\\Time4Midi\\node_modules\\app-builder-lib\\templates\\nsis\\include\\StdUtils.nsh\"\n!addincludedir \"C:\\Projects\\Time4Midi\\node_modules\\app-builder-lib\\templates\\nsis\\include\"\n!macro _isUpdated _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"updated\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isUpdated `\"\" isUpdated \"\"`\n\n!macro _isForceRun _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"force-run\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForceRun `\"\" isForceRun \"\"`\n\n!macro _isKeepShortcuts _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"keep-shortcuts\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isKeepShortcuts `\"\" isKeepShortcuts \"\"`\n\n!macro _isNoDesktopShortcut _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"no-desktop-shortcut\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isNoDesktopShortcut `\"\" isNoDesktopShortcut \"\"`\n\n!macro _isDeleteAppData _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"delete-app-data\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isDeleteAppData `\"\" isDeleteAppData \"\"`\n\n!macro _isForAllUsers _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"allusers\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForAllUsers `\"\" isForAllUsers \"\"`\n\n!macro _isForCurrentUser _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"currentuser\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForCurrentUser `\"\" isForCurrentUser \"\"`\n\n!macro addLangs\n  !insertmacro MUI_LANGUAGE \"English\"\n  !insertmacro MUI_LANGUAGE \"German\"\n  !insertmacro MUI_LANGUAGE \"French\"\n  !insertmacro MUI_LANGUAGE \"SpanishInternational\"\n  !insertmacro MUI_LANGUAGE \"SimpChinese\"\n  !insertmacro MUI_LANGUAGE \"TradChinese\"\n  !insertmacro MUI_LANGUAGE \"Japanese\"\n  !insertmacro MUI_LANGUAGE \"Korean\"\n  !insertmacro MUI_LANGUAGE \"Italian\"\n  !insertmacro MUI_LANGUAGE \"Dutch\"\n  !insertmacro MUI_LANGUAGE \"Danish\"\n  !insertmacro MUI_LANGUAGE \"Swedish\"\n  !insertmacro MUI_LANGUAGE \"Norwegian\"\n  !insertmacro MUI_LANGUAGE \"Finnish\"\n  !insertmacro MUI_LANGUAGE \"Russian\"\n  !insertmacro MUI_LANGUAGE \"Portuguese\"\n  !insertmacro MUI_LANGUAGE \"PortugueseBR\"\n  !insertmacro MUI_LANGUAGE \"Polish\"\n  !insertmacro MUI_LANGUAGE \"Ukrainian\"\n  !insertmacro MUI_LANGUAGE \"Czech\"\n  !insertmacro MUI_LANGUAGE \"Slovak\"\n  !insertmacro MUI_LANGUAGE \"Hungarian\"\n  !insertmacro MUI_LANGUAGE \"Arabic\"\n  !insertmacro MUI_LANGUAGE \"Turkish\"\n  !insertmacro MUI_LANGUAGE \"Thai\"\n  !insertmacro MUI_LANGUAGE \"Vietnamese\"\n!macroend\n\n!include \"C:\\Users\\jh\\AppData\\Local\\Temp\\t-R6ALfD\\1-messages.nsh\"\n!addplugindir /x86-unicode \"C:\\Users\\jh\\AppData\\Local\\electron-builder\\Cache\\nsis-resources-3.4.1\\nsis-resources-3.4.1-2jx2y\\plugins\\x86-unicode\"\n\n!include \"common.nsh\"\n!include \"extractAppPackage.nsh\"\n\n# https://github.com/electron-userland/electron-builder/issues/3972#issuecomment-505171582\nCRCCheck off\nWindowIcon Off\nAutoCloseWindow True\nRequestExecutionLevel ${REQUEST_EXECUTION_LEVEL}\n\nFunction .onInit\n  !ifndef SPLASH_IMAGE\n    SetSilent silent\n  !endif\n\n  !insertmacro check64BitAndSetRegView\nFunctionEnd\n\nFunction .onGUIInit\n  InitPluginsDir\n\n  !ifdef SPLASH_IMAGE\n    File /oname=$PLUGINSDIR\\splash.bmp \"${SPLASH_IMAGE}\"\n    BgImage::SetBg $PLUGINSDIR\\splash.bmp\n    BgImage::Redraw\n  !endif\nFunctionEnd\n\nSection\n  !ifdef SPLASH_IMAGE\n    HideWindow\n  !endif\n\n  StrCpy $INSTDIR \"$PLUGINSDIR\\app\"\n  !ifdef UNPACK_DIR_NAME\n    StrCpy $INSTDIR \"$TEMP\\${UNPACK_DIR_NAME}\"\n  !endif\n\n  RMDir /r $INSTDIR\n  SetOutPath $INSTDIR\n\n  !ifdef APP_DIR_64\n    !ifdef APP_DIR_ARM64\n      !ifdef APP_DIR_32\n        ${if} ${IsNativeARM64}\n          File /r \"${APP_DIR_ARM64}\\*.*\"\n        ${elseif} ${RunningX64}\n          File /r \"${APP_DIR_64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_32}\\*.*\"\n        ${endIf}\n      !else\n        ${if} ${IsNativeARM64}\n          File /r \"${APP_DIR_ARM64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_64}\\*.*\"\n        {endIf}\n      !endif\n    !else\n      !ifdef APP_DIR_32\n        ${if} ${RunningX64}\n          File /r \"${APP_DIR_64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_32}\\*.*\"\n        ${endIf}\n      !else\n        File /r \"${APP_DIR_64}\\*.*\"\n      !endif\n    !endif\n  !else\n    !ifdef APP_DIR_32\n      File /r \"${APP_DIR_32}\\*.*\"\n    !else\n      !insertmacro extractEmbeddedAppPackage\n    !endif\n  !endif\n\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_DIR\", \"$EXEDIR\").r0'\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_FILE\", \"$EXEPATH\").r0'\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_APP_FILENAME\", \"${APP_FILENAME}\").r0'\n  ${StdUtils.GetAllParameters} $R0 0\n\n  !ifdef SPLASH_IMAGE\n    BgImage::Destroy\n  !endif\n\n\tExecWait \"$INSTDIR\\${APP_EXECUTABLE_FILENAME} $R0\" $0\n  SetErrorLevel $0\n\n  SetOutPath $EXEDIR\n\tRMDir /r $INSTDIR\nSectionEnd\n"
+  script: "!include \"C:\\Projects\\Time4Midi\\node_modules\\app-builder-lib\\templates\\nsis\\include\\StdUtils.nsh\"\n!addincludedir \"C:\\Projects\\Time4Midi\\node_modules\\app-builder-lib\\templates\\nsis\\include\"\n!macro _isUpdated _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"updated\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isUpdated `\"\" isUpdated \"\"`\n\n!macro _isForceRun _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"force-run\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForceRun `\"\" isForceRun \"\"`\n\n!macro _isKeepShortcuts _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"keep-shortcuts\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isKeepShortcuts `\"\" isKeepShortcuts \"\"`\n\n!macro _isNoDesktopShortcut _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"no-desktop-shortcut\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isNoDesktopShortcut `\"\" isNoDesktopShortcut \"\"`\n\n!macro _isDeleteAppData _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"delete-app-data\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isDeleteAppData `\"\" isDeleteAppData \"\"`\n\n!macro _isForAllUsers _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"allusers\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForAllUsers `\"\" isForAllUsers \"\"`\n\n!macro _isForCurrentUser _a _b _t _f\n  ${StdUtils.TestParameter} $R9 \"currentuser\"\n  StrCmp \"$R9\" \"true\" `${_t}` `${_f}`\n!macroend\n!define isForCurrentUser `\"\" isForCurrentUser \"\"`\n\n!macro addLangs\n  !insertmacro MUI_LANGUAGE \"English\"\n  !insertmacro MUI_LANGUAGE \"German\"\n  !insertmacro MUI_LANGUAGE \"French\"\n  !insertmacro MUI_LANGUAGE \"SpanishInternational\"\n  !insertmacro MUI_LANGUAGE \"SimpChinese\"\n  !insertmacro MUI_LANGUAGE \"TradChinese\"\n  !insertmacro MUI_LANGUAGE \"Japanese\"\n  !insertmacro MUI_LANGUAGE \"Korean\"\n  !insertmacro MUI_LANGUAGE \"Italian\"\n  !insertmacro MUI_LANGUAGE \"Dutch\"\n  !insertmacro MUI_LANGUAGE \"Danish\"\n  !insertmacro MUI_LANGUAGE \"Swedish\"\n  !insertmacro MUI_LANGUAGE \"Norwegian\"\n  !insertmacro MUI_LANGUAGE \"Finnish\"\n  !insertmacro MUI_LANGUAGE \"Russian\"\n  !insertmacro MUI_LANGUAGE \"Portuguese\"\n  !insertmacro MUI_LANGUAGE \"PortugueseBR\"\n  !insertmacro MUI_LANGUAGE \"Polish\"\n  !insertmacro MUI_LANGUAGE \"Ukrainian\"\n  !insertmacro MUI_LANGUAGE \"Czech\"\n  !insertmacro MUI_LANGUAGE \"Slovak\"\n  !insertmacro MUI_LANGUAGE \"Hungarian\"\n  !insertmacro MUI_LANGUAGE \"Arabic\"\n  !insertmacro MUI_LANGUAGE \"Turkish\"\n  !insertmacro MUI_LANGUAGE \"Thai\"\n  !insertmacro MUI_LANGUAGE \"Vietnamese\"\n!macroend\n\n!addplugindir /x86-unicode \"C:\\Users\\jh\\AppData\\Local\\electron-builder\\Cache\\nsis-resources-3.4.1\\nsis-resources-3.4.1-2jx2y\\plugins\\x86-unicode\"\n!include \"C:\\Users\\jh\\AppData\\Local\\Temp\\t-jBU1Xj\\1-messages.nsh\"\n\n!include \"common.nsh\"\n!include \"extractAppPackage.nsh\"\n\n# https://github.com/electron-userland/electron-builder/issues/3972#issuecomment-505171582\nCRCCheck off\nWindowIcon Off\nAutoCloseWindow True\nRequestExecutionLevel ${REQUEST_EXECUTION_LEVEL}\n\nFunction .onInit\n  !ifndef SPLASH_IMAGE\n    SetSilent silent\n  !endif\n\n  !insertmacro check64BitAndSetRegView\nFunctionEnd\n\nFunction .onGUIInit\n  InitPluginsDir\n\n  !ifdef SPLASH_IMAGE\n    File /oname=$PLUGINSDIR\\splash.bmp \"${SPLASH_IMAGE}\"\n    BgImage::SetBg $PLUGINSDIR\\splash.bmp\n    BgImage::Redraw\n  !endif\nFunctionEnd\n\nSection\n  !ifdef SPLASH_IMAGE\n    HideWindow\n  !endif\n\n  StrCpy $INSTDIR \"$PLUGINSDIR\\app\"\n  !ifdef UNPACK_DIR_NAME\n    StrCpy $INSTDIR \"$TEMP\\${UNPACK_DIR_NAME}\"\n  !endif\n\n  RMDir /r $INSTDIR\n  SetOutPath $INSTDIR\n\n  !ifdef APP_DIR_64\n    !ifdef APP_DIR_ARM64\n      !ifdef APP_DIR_32\n        ${if} ${IsNativeARM64}\n          File /r \"${APP_DIR_ARM64}\\*.*\"\n        ${elseif} ${RunningX64}\n          File /r \"${APP_DIR_64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_32}\\*.*\"\n        ${endIf}\n      !else\n        ${if} ${IsNativeARM64}\n          File /r \"${APP_DIR_ARM64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_64}\\*.*\"\n        {endIf}\n      !endif\n    !else\n      !ifdef APP_DIR_32\n        ${if} ${RunningX64}\n          File /r \"${APP_DIR_64}\\*.*\"\n        ${else}\n          File /r \"${APP_DIR_32}\\*.*\"\n        ${endIf}\n      !else\n        File /r \"${APP_DIR_64}\\*.*\"\n      !endif\n    !endif\n  !else\n    !ifdef APP_DIR_32\n      File /r \"${APP_DIR_32}\\*.*\"\n    !else\n      !insertmacro extractEmbeddedAppPackage\n    !endif\n  !endif\n\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_DIR\", \"$EXEDIR\").r0'\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_FILE\", \"$EXEPATH\").r0'\n  System::Call 'Kernel32::SetEnvironmentVariable(t, t)i (\"PORTABLE_EXECUTABLE_APP_FILENAME\", \"${APP_FILENAME}\").r0'\n  ${StdUtils.GetAllParameters} $R0 0\n\n  !ifdef SPLASH_IMAGE\n    BgImage::Destroy\n  !endif\n\n\tExecWait \"$INSTDIR\\${APP_EXECUTABLE_FILENAME} $R0\" $0\n  SetErrorLevel $0\n\n  SetOutPath $EXEDIR\n\tRMDir /r $INSTDIR\nSectionEnd\n"
diff --git a/dist/win-unpacked/Time4Midi.exe b/dist/win-unpacked/Time4Midi.exe
index dfe4568..4b96055 100644
Binary files a/dist/win-unpacked/Time4Midi.exe and b/dist/win-unpacked/Time4Midi.exe differ
diff --git a/dist/win-unpacked/resources/app.asar b/dist/win-unpacked/resources/app.asar
index edee2fc..76c0e3e 100644
Binary files a/dist/win-unpacked/resources/app.asar and b/dist/win-unpacked/resources/app.asar differ
diff --git a/package-lock.json b/package-lock.json
index 9ed54de..0e88d29 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,14 +1,14 @@
 {
   "name": "time4midi",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "time4midi",
-      "version": "0.1.0",
+      "version": "0.2.0",
       "dependencies": {
-        "knx": "^0.0.1",
+        "knx": "^2.5.4",
         "modbus-serial": "^8.0.25",
         "mqtt": "^5.10.4",
         "serialport": "^13.0.0"
@@ -1171,6 +1171,27 @@
       ],
       "license": "MIT"
     },
+    "node_modules/binary-parser": {
+      "version": "1.1.5",
+      "resolved": "https://registry.npmjs.org/binary-parser/-/binary-parser-1.1.5.tgz",
+      "integrity": "sha512-KsW0sfQ3e5Lpk8EVP44okdpOUhUlVaQ5HQ/qBKLpuMgEV29pTIfPvFobs9j4kp/4BqOSZ+kZpC7f4mleVonTRw==",
+      "license": "MIT"
+    },
+    "node_modules/binary-protocol": {
+      "version": "0.0.0",
+      "resolved": "https://registry.npmjs.org/binary-protocol/-/binary-protocol-0.0.0.tgz",
+      "integrity": "sha512-kcFqbqtZnZEGSY8Jh6dEO6VbxJDZu1tqJc3LODqADPHrDwHQwoTNdGTHW4sLhmNXeWUOZKjfRfopAu5xpRQbPw==",
+      "license": "MIT",
+      "dependencies": {
+        "bluebird": "~2.2.2"
+      }
+    },
+    "node_modules/binary-protocol/node_modules/bluebird": {
+      "version": "2.2.2",
+      "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-2.2.2.tgz",
+      "integrity": "sha512-NqzuS2y44FmP++Ihv6/PgXpNRB+c282TKq0URBTQdA+EqPpR1Qu44QY8H8667LA39iOIaVHpmRPI4gpthYT8Ug==",
+      "license": "MIT"
+    },
     "node_modules/bluebird": {
       "version": "3.7.2",
       "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.7.2.tgz",
@@ -2595,6 +2616,15 @@
         "node": ">= 12"
       }
     },
+    "node_modules/ipaddr.js": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/ipaddr.js/-/ipaddr.js-1.2.0.tgz",
+      "integrity": "sha512-ku//LD7ie/m9UVGCm9KweBIIHP4mB0maNGvav6Hz778fQCNLQF7iZ+H/UuHuqmjJCHCpA5hw8hOeRKxZl8IlXw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.10"
+      }
+    },
     "node_modules/is-fullwidth-code-point": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz",
@@ -2755,9 +2785,26 @@
       }
     },
     "node_modules/knx": {
-      "version": "0.0.1",
-      "resolved": "https://registry.npmjs.org/knx/-/knx-0.0.1.tgz",
-      "integrity": "sha512-6AikhvtVK/U4CKL0/+vrLXsg8e/CNTUxmdKHgeLgWDObb/ggdr8BXeB7xmPjmnA+1ieDS6liFIkuHAPAlD0k9Q==",
+      "version": "2.5.4",
+      "resolved": "https://registry.npmjs.org/knx/-/knx-2.5.4.tgz",
+      "integrity": "sha512-h+WMbx2NPgCL1Vr4X8xAsTV9E+72XjPviKRv67iJLomapENO25ZsRGq8egvqUJwtnsordJGOxxUA4o1jMOzQYw==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "^6.14.4",
+        "binary-parser": "1.1.5",
+        "binary-protocol": "0.0.0",
+        "ipaddr.js": "1.2.0",
+        "log-driver": "1.2.7",
+        "machina": "^4.0.2"
+      },
+      "engines": {
+        "node": ">=6"
+      }
+    },
+    "node_modules/knx/node_modules/@types/node": {
+      "version": "6.14.13",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-6.14.13.tgz",
+      "integrity": "sha512-J1F0XJ/9zxlZel5ZlbeSuHW2OpabrUAqpFuC2sm2I3by8sERQ8+KCjNKUcq8QHuzpGMWiJpo9ZxeHrqrP2KzQw==",
       "license": "MIT"
     },
     "node_modules/lazy-val": {
@@ -2771,9 +2818,17 @@
       "version": "4.18.1",
       "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.18.1.tgz",
       "integrity": "sha512-dMInicTPVE8d1e5otfwmmjlxkZoUpiVLwyeTdUsi/Caj/gfzzblBcCE5sRHV/AsjuCmxWrte2TNGSYuCeCq+0Q==",
-      "dev": true,
       "license": "MIT"
     },
+    "node_modules/log-driver": {
+      "version": "1.2.7",
+      "resolved": "https://registry.npmjs.org/log-driver/-/log-driver-1.2.7.tgz",
+      "integrity": "sha512-U7KCmLdqsGHBLeWqYlFA0V0Sl6P08EE1ZrmA9cxjUE0WVqT9qnyVDPz1kzpFEP0jdJuFnasWIfSd7fsaNXkpbg==",
+      "license": "ISC",
+      "engines": {
+        "node": ">=0.8.6"
+      }
+    },
     "node_modules/lowercase-keys": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-2.0.0.tgz",
@@ -2797,6 +2852,17 @@
         "node": ">=10"
       }
     },
+    "node_modules/machina": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/machina/-/machina-4.0.2.tgz",
+      "integrity": "sha512-OOlFrW1rd783S6tF36v5Ie/TM64gfvSl9kYLWL2cPA31J71HHWW3XrgSe1BZSFAPkh8532CMJMLv/s9L2aopiA==",
+      "dependencies": {
+        "lodash": "^4.17.5"
+      },
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
     "node_modules/matcher": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/matcher/-/matcher-3.0.0.tgz",
diff --git a/package.json b/package.json
index e04971a..e9e6d87 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "time4midi",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Cross-platform timeline editor for MIDI notes and Art-Net values, slaved to incoming timecode.",
   "main": "main.js",
   "author": "J.H. Artworks",
@@ -13,7 +13,7 @@
     "electron-builder": "^26.15.3"
   },
   "dependencies": {
-    "knx": "^0.0.1",
+    "knx": "^2.5.4",
     "modbus-serial": "^8.0.25",
     "mqtt": "^5.10.4",
     "serialport": "^13.0.0"
diff --git a/preload.js b/preload.js
index 142c3f9..42bcf78 100644
--- a/preload.js
+++ b/preload.js
@@ -4,10 +4,30 @@ const dgram = require("node:dgram");
 const fs = require("node:fs/promises");
 const os = require("node:os");
 const { pathToFileURL } = require("node:url");
-const mqtt = require("mqtt");
-const { SerialPort } = require("serialport");
-const ModbusRTU = require("modbus-serial");
-const knx = require("knx");
+function loadOptionalDependency(packageName) {
+  try {
+    return {
+      module: require(packageName),
+      error: null
+    };
+  } catch (error) {
+    console.error(`[time4midi] Optional dependency "${packageName}" failed to load:`, error);
+    return {
+      module: null,
+      error
+    };
+  }
+}
+
+const mqttDependency = loadOptionalDependency("mqtt");
+const serialportDependency = loadOptionalDependency("serialport");
+const modbusDependency = loadOptionalDependency("modbus-serial");
+const knxDependency = loadOptionalDependency("knx");
+
+const mqtt = mqttDependency.module;
+const SerialPort = serialportDependency.module?.SerialPort || null;
+const ModbusRTU = modbusDependency.module || null;
+const knx = knxDependency.module || null;
 
 const ARTNET_PORT = 6454;
 const SACN_PORT = 5568;
@@ -34,6 +54,11 @@ function emitStatus(target, message) {
   }
 }
 
+function dependencyError(label, dependency) {
+  const detail = dependency.error?.message || "Modul nicht verfuegbar";
+  return new Error(`${label} Modul nicht verfuegbar: ${detail}`);
+}
+
 function addStatusApi(target, handler) {
   target.statusListeners.add(handler);
   handler({
@@ -120,7 +145,7 @@ const serialState = {
 
 const modbusTcpState = {
   ...createStatusEmitter(),
-  client: new ModbusRTU(),
+  client: null,
   connected: false,
   signature: "",
   config: {
@@ -134,7 +159,7 @@ const modbusTcpState = {
 
 const modbusRtuState = {
   ...createStatusEmitter(),
-  client: new ModbusRTU(),
+  client: null,
   connected: false,
   signature: "",
   config: {
@@ -635,6 +660,11 @@ function configureMqtt(nextConfig) {
     return mqttState.config;
   }
 
+  if (!mqtt) {
+    emitStatus(mqttState, dependencyError("MQTT", mqttDependency).message);
+    return mqttState.config;
+  }
+
   const options = { reconnectPeriod: 1000 };
   if (mqttState.config.clientId) options.clientId = mqttState.config.clientId;
   if (mqttState.config.username) options.username = mqttState.config.username;
@@ -705,11 +735,18 @@ function closeSerialPort() {
 async function configureSerial(nextConfig) {
   serialState.config = normalizeSerialConfig(nextConfig);
   await closeSerialPort();
+  if (serialState.config.enabled && !SerialPort) {
+    emitStatus(serialState, dependencyError("Serial", serialportDependency).message);
+    return serialState.config;
+  }
   emitStatus(serialState, "");
   return serialState.config;
 }
 
 async function ensureSerialPortOpen() {
+  if (!SerialPort) {
+    throw dependencyError("Serial", serialportDependency);
+  }
   if (!serialState.config.enabled) {
     throw new Error("Serial deaktiviert");
   }
@@ -768,6 +805,9 @@ async function sendSerial(payload) {
 }
 
 async function listSerialPorts() {
+  if (!SerialPort) {
+    throw dependencyError("Serial", serialportDependency);
+  }
   const ports = await SerialPort.list();
   return ports.map((port) => ({
     path: port.path,
@@ -799,9 +839,11 @@ async function listNetworkInterfaces() {
 }
 
 async function disconnectModbusClient(state) {
-  if (state.client?.isOpen) {
+  const client = state.client;
+  state.client = null;
+  if (client?.isOpen) {
     try {
-      await state.client.close();
+      await client.close();
     } catch (_error) {
       // Best effort close.
     }
@@ -813,6 +855,10 @@ async function disconnectModbusClient(state) {
 async function configureModbusTcp(nextConfig) {
   modbusTcpState.config = normalizeModbusTcpConfig(nextConfig);
   await disconnectModbusClient(modbusTcpState);
+  if (modbusTcpState.config.enabled && !ModbusRTU) {
+    emitStatus(modbusTcpState, dependencyError("Modbus TCP", modbusDependency).message);
+    return modbusTcpState.config;
+  }
   emitStatus(modbusTcpState, "");
   return modbusTcpState.config;
 }
@@ -820,11 +866,18 @@ async function configureModbusTcp(nextConfig) {
 async function configureModbusRtu(nextConfig) {
   modbusRtuState.config = normalizeModbusRtuConfig(nextConfig);
   await disconnectModbusClient(modbusRtuState);
+  if (modbusRtuState.config.enabled && !ModbusRTU) {
+    emitStatus(modbusRtuState, dependencyError("Modbus RTU", modbusDependency).message);
+    return modbusRtuState.config;
+  }
   emitStatus(modbusRtuState, "");
   return modbusRtuState.config;
 }
 
 async function ensureModbusTcpConnected() {
+  if (!ModbusRTU) {
+    throw dependencyError("Modbus TCP", modbusDependency);
+  }
   if (!modbusTcpState.config.enabled) {
     throw new Error("Modbus TCP deaktiviert");
   }
@@ -833,6 +886,7 @@ async function ensureModbusTcpConnected() {
     return modbusTcpState.client;
   }
   await disconnectModbusClient(modbusTcpState);
+  modbusTcpState.client = new ModbusRTU();
   await modbusTcpState.client.connectTCP(modbusTcpState.config.host, {
     port: modbusTcpState.config.port,
     timeout: modbusTcpState.config.timeout,
@@ -846,6 +900,9 @@ async function ensureModbusTcpConnected() {
 }
 
 async function ensureModbusRtuConnected() {
+  if (!ModbusRTU) {
+    throw dependencyError("Modbus RTU", modbusDependency);
+  }
   if (!modbusRtuState.config.enabled) {
     throw new Error("Modbus RTU deaktiviert");
   }
@@ -857,6 +914,7 @@ async function ensureModbusRtuConnected() {
     return modbusRtuState.client;
   }
   await disconnectModbusClient(modbusRtuState);
+  modbusRtuState.client = new ModbusRTU();
   await modbusRtuState.client.connectRTUBuffered(modbusRtuState.config.path, {
     baudRate: modbusRtuState.config.baudRate,
     parity: modbusRtuState.config.parity,
@@ -929,11 +987,18 @@ function disconnectKnx() {
 async function configureKnx(nextConfig) {
   knxState.config = normalizeKnxConfig(nextConfig);
   await disconnectKnx();
+  if (knxState.config.enabled && !knx) {
+    emitStatus(knxState, dependencyError("KNX", knxDependency).message);
+    return knxState.config;
+  }
   emitStatus(knxState, "");
   return knxState.config;
 }
 
 async function ensureKnxConnection() {
+  if (!knx) {
+    throw dependencyError("KNX", knxDependency);
+  }
   if (!knxState.config.enabled) {
     throw new Error("KNX deaktiviert");
   }