diff --git a/.env.development b/.env.development
index 676983f..53add08 100644
--- a/.env.development
+++ b/.env.development
@@ -6,6 +6,6 @@ NEXT_PUBLIC_USE_MOCK_BACKEND_LOOP_START=false
 NEXT_PUBLIC_EXPORT_STATIC=false
 NEXT_PUBLIC_USE_CGI=false
 # App-Versionsnummer
-NEXT_PUBLIC_APP_VERSION=1.6.659
+NEXT_PUBLIC_APP_VERSION=1.6.660
 NEXT_PUBLIC_CPL_MODE=json   # json (Entwicklungsumgebung) oder jsSimulatedProd (CPL ->CGI-Interface-Simulator) oder production (CPL-> CGI-Interface Platzhalter)
 
diff --git a/.env.production b/.env.production
index 5bc7909..813d111 100644
--- a/.env.production
+++ b/.env.production
@@ -5,5 +5,5 @@ NEXT_PUBLIC_CPL_API_PATH=/CPL
 NEXT_PUBLIC_EXPORT_STATIC=true
 NEXT_PUBLIC_USE_CGI=true
 # App-Versionsnummer
-NEXT_PUBLIC_APP_VERSION=1.6.659
+NEXT_PUBLIC_APP_VERSION=1.6.660
 NEXT_PUBLIC_CPL_MODE=production
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7de33b6..8bf72f1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## [1.6.660] – 2025-07-31
+
+- fix: Schleifenwiderstand (TDR) Messung starten Button auf der Produktion
+
+---
 ## [1.6.659] – 2025-07-31
 
 - feat: Display und Chart für KÜs
diff --git a/components/main/kabelueberwachung/kue705FO/Charts/TDRChart/TDRChartActionBar.tsx b/components/main/kabelueberwachung/kue705FO/Charts/TDRChart/TDRChartActionBar.tsx
index f60ec07..6724d5f 100644
--- a/components/main/kabelueberwachung/kue705FO/Charts/TDRChart/TDRChartActionBar.tsx
+++ b/components/main/kabelueberwachung/kue705FO/Charts/TDRChart/TDRChartActionBar.tsx
@@ -82,6 +82,33 @@ const TDRChartActionBar: React.FC = () => {
     }
   };
 
+  // 📌 TDR Messung starten
+  const handleStartTDR = async () => {
+    if (selectedSlot === null) {
+      alert("⚠️ Bitte zuerst einen KÜ auswählen!");
+      return;
+    }
+
+    const cgiUrl = `${window.location.origin}/CPL?kabelueberwachung.html&KTT${selectedSlot}=1`;
+
+    try {
+      console.log("🚀 Starte TDR Messung für Slot:", selectedSlot);
+      console.log("📡 CGI URL:", cgiUrl);
+
+      const response = await fetch(cgiUrl);
+
+      if (!response.ok) {
+        throw new Error(`CGI-Fehler: ${response.status}`);
+      }
+
+      console.log("✅ TDR Messung gestartet für Slot", selectedSlot);
+      alert(`✅ TDR Messung für Slot ${selectedSlot + 1} gestartet`);
+    } catch (err) {
+      console.error("❌ Fehler beim Starten der TDR Messung:", err);
+      alert("❌ Fehler beim Starten der TDR Messung.");
+    }
+  };
+
   // 📥 Beim Slot-Wechsel TDM-Liste + letzte ID laden
   useEffect(() => {
     if (selectedSlot !== null) {
@@ -119,6 +146,15 @@ const TDRChartActionBar: React.FC = () => {
         </button>
       )}
 
+      {/* 🚀 TDR starten */}
+      <button
+        onClick={handleStartTDR}
+        className="px-4 py-1 bg-littwin-blue text-white rounded text-sm whitespace-nowrap "
+        disabled={selectedSlot === null}
+      >
+        TDR starten
+      </button>
+
       {/* 🔽 Dropdown für Messungen */}
       <div className="flex items-center space-x-2">
         <Listbox
@@ -131,9 +167,9 @@ const TDRChartActionBar: React.FC = () => {
           }}
           disabled={idsForSlot.length === 0}
         >
-          <div className="relative w-72">
+          <div className="relative w-96">
             <Listbox.Button className="w-full border px-2 py-1 rounded text-left bg-white flex justify-between items-center text-sm">
-              <span>
+              <span className="whitespace-nowrap overflow-hidden text-ellipsis">
                 {selectedId
                   ? (() => {
                       const selected = idsForSlot.find(
@@ -172,7 +208,7 @@ const TDRChartActionBar: React.FC = () => {
                   key={entry.id}
                   value={entry.id}
                   className={({ selected, active }) =>
-                    `px-4 py-1 cursor-pointer ${
+                    `px-4 py-1 cursor-pointer whitespace-nowrap overflow-hidden text-ellipsis ${
                       selected
                         ? "bg-littwin-blue text-white"
                         : active
diff --git a/components/main/settingsPageComponents/UserManagementSettings.tsx b/components/main/settingsPageComponents/UserManagementSettings.tsx
index fe6327b..e6912f8 100644
--- a/components/main/settingsPageComponents/UserManagementSettings.tsx
+++ b/components/main/settingsPageComponents/UserManagementSettings.tsx
@@ -31,6 +31,12 @@ const UserManagementSettings: React.FC = () => {
     );
   };
 
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === "Enter") {
+      handleLogin();
+    }
+  };
+
   return (
     <div className="p-6 md:p-3 bg-gray-100 max-w-5xl mr-auto">
       <h2 className="text-sm md:text-md font-bold mb-4">Login Admin-Bereich</h2>
@@ -54,6 +60,7 @@ const UserManagementSettings: React.FC = () => {
                 className="border border-gray-300 rounded h-8 p-1 w-full text-xs"
                 value={username}
                 onChange={(e) => setUsername(e.target.value)}
+                onKeyDown={handleKeyDown}
               />
               <input
                 type="password"
@@ -61,6 +68,7 @@ const UserManagementSettings: React.FC = () => {
                 className="border border-gray-300 rounded h-8 p-1 w-full text-xs"
                 value={password}
                 onChange={(e) => setPassword(e.target.value)}
+                onKeyDown={handleKeyDown}
               />
               <button
                 type="button"
diff --git a/package-lock.json b/package-lock.json
index 5dd8480..5305484 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "cpl-v4",
-  "version": "1.6.659",
+  "version": "1.6.660",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "cpl-v4",
-      "version": "1.6.659",
+      "version": "1.6.660",
       "dependencies": {
         "@fontsource/roboto": "^5.1.0",
         "@headlessui/react": "^2.2.4",
diff --git a/package.json b/package.json
index c4db6a1..264b4c4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cpl-v4",
-  "version": "1.6.659",
+  "version": "1.6.660",
   "private": true,
   "scripts": {
     "dev": "next dev",