diff --git a/public/index.html b/public/index.html
index 265f225..f820118 100644
--- a/public/index.html
+++ b/public/index.html
@@ -92,7 +92,7 @@
             this.mac = "";
             this.antName = "";
             this.adc = 0;
-            this.lastSeen = 0;
+            this.online = false;
             this.bands = [];
         }
     }
@@ -242,6 +242,24 @@
             ctx.clearRect(0, 0, sz, sz);
             ctx.drawImage(this.bgCanvas, 0, 0);
 
+            const isOffline = !this.state.online;
+
+            if (isOffline) {
+                // Grey overlay
+                ctx.beginPath();
+                ctx.arc(cx, cy, sz / 2 * 0.9, 0, 2 * Math.PI);
+                ctx.fillStyle = 'rgba(0, 0, 0, 0.6)';
+                ctx.fill();
+
+                // OFFLINE label
+                ctx.font = 'bold 50px Arial';
+                ctx.textAlign = 'center';
+                ctx.textBaseline = 'middle';
+                ctx.fillStyle = '#666';
+                ctx.fillText('OFFLINE', cx, cy);
+                return;
+            }
+
             // Setpoint line (only while turning)
             if (targetAngle != null && status !== 4) {
                 ctx.beginPath();
@@ -412,10 +430,9 @@
 
             this.els.az.innerText = this.state.azimuth;
 
-            const isOffline = (Date.now() - this.state.lastSeen) > 1500;
-            this.els.online.innerHTML = isOffline
-                ? " | <span class=\"text-red\">&bull;</span> Offline"
-                : " | <span class=\"text-white\">&bull;</span> Connected";
+            this.els.online.innerHTML = this.state.online
+                ? " | <span class=\"text-white\">&bull;</span> Connected"
+                : " | <span class=\"text-red\">&bull;</span> Offline";
         }
 
         updateTurnedBy(sourceIp, targetAz) {
@@ -457,6 +474,7 @@
             document.title = Object.values(this.rotators)
                 .map(r => r.state.antName || "Rotator")
                 .join(" / ");
+
         }
 
         async startWs() {
@@ -483,13 +501,15 @@
                         if (!rot) continue;
 
                         if (rotData.dynamic) {
-                            const { azimuth, status, adc } = rotData.dynamic;
-                            let needsRender = rot.state.azimuth !== azimuth || rot.state.status !== status;
+                            const { azimuth, status, adc, online } = rotData.dynamic;
+                            let needsRender = rot.state.azimuth !== azimuth
+                                || rot.state.status !== status
+                                || rot.state.online !== online;
 
                             rot.state.adc = adc;
                             rot.state.azimuth = azimuth;
                             rot.state.status = status;
-                            rot.state.lastSeen = Date.now();
+                            rot.state.online = online;
 
                             if (needsRender) rot.ui.renderer.render();
                             rot.ui.updateDynamic();
diff --git a/src/RotClient.ts b/src/RotClient.ts
index 7120925..c399f9b 100644
--- a/src/RotClient.ts
+++ b/src/RotClient.ts
@@ -65,7 +65,13 @@ export default class RotClient {
 			{ key: 'status',  url: 'readStat', numType: NumType.Int   },
 		];
 
-		const data = await this.readEndpoints(endpoints) as unknown as DynamicData;
+		const raw = await this.readEndpoints(endpoints);
+		const data: DynamicData = {
+			adc: raw.adc as number | null,
+			azimuth: raw.azimuth as number | null,
+			status: raw.status as number | null,
+			online: raw.azimuth !== null,
+		};
 
 		if (this.dynamicData !== null) {
 			const oldData = this.dynamicData;
diff --git a/src/types.ts b/src/types.ts
index df377ae..895d23b 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -19,6 +19,7 @@ export interface DynamicData {
 	adc: number | null;
 	azimuth: number | null;
 	status: number | null;
+	online: boolean;
 }
 
 export interface InitData {