> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pads4.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create a cluster

Clusters in PADS4 allow multiple Viewers to work together as a **single unit**, ensuring continuous display functionality even if one Viewer fails. This guide walks you through **creating a Cluster**, **defining a Cluster presentation**, and **automating Viewer fallback**.

## **Step 1: Creating a Cluster**

1. **Open PADS4 CTRL Center**.
2. Navigate to **Viewers > Clusters**.
3. Click **New** to create a new Cluster.
4. **Enter Cluster Details**:
   * Provide a **unique name** for the Cluster.
   * (Optional) Add a **description**.
5. **Add Viewers**:
   * Click **"+"** to select Viewers from the available list.
   * Specify the **exact location** of each Viewer within the Cluster *(horizontal or vertical alignment)*.
6. Click **Create** to finalize the Cluster.

## **Step 2: Defining a Cluster Presentation**

Now that the Cluster is created, we need to create a **presentation that adapts dynamically when a Viewer fails**.

### **Example: A 2-Viewer Cluster**

* **Viewer 1** will display "Viewer 1".
* **Viewer 2** will display "Viewer 2".
* If **Viewer 1 fails**, **Viewer 2 will take over** and display "Viewer 1" instead.

### **Step 2.1: Creating the Presentation**

1. **Open PADS4 Designer**.
2. **Create a new presentation**.

#### **Page 1: Setup for Viewer 1**

1. **Create a text element** and set its text to `"Viewer 1"`.
2. **Go to Page Properties** and **uncheck visibility** *(page is hidden by default)*.
3. **Define a Page Rule**:
   * **Condition:**
     * **Value 1:** `[Viewer Variable]` → **HorizontalPosition**
     * **Operation:** `Equals to`
     * **Value 2:** `Constant Value = 1`
   * **Action:** **Set visibility to "visible"**.

#### **Page 2: Setup for Viewer 2**

1. **Duplicate Page 1** to create **Page 2**.
2. **Change the text** from `"Viewer 1"` to `"Viewer 2"`.
3. **Modify the Page Rule**:
   * **Change "Constant Value = 1" to "Constant Value = 2"**.

## **Step 3: Scheduling the Cluster Presentation**

1. **Open PADS4 Scheduler**.
2. **Schedule the presentation** to **Viewer 1** and **Viewer 2**.
3. **Start both Viewers**.
4. You will see:
   * **Viewer 1 shows "Viewer 1".**
   * **Viewer 2 shows "Viewer 2".**

## **Step 4: Simulating a Viewer Failure**

1. **Close Viewer 1**.
2. **Observe Viewer 2**:
   * **Viewer 2 will now display "Viewer 1".**
   * This happens **automatically** because **PADS4 moves content dynamically** when a Viewer fails.

## **Why Use Clusters?**

* **Ensures content continuity** even when hardware fails.
* **Automatically reassigns content** to available Viewers.
* **Ideal for digital signage, airport displays, menu boards, and more**.
* **No cluster size limit** – scale as needed.

This setup provides a **smart, automated digital signage solution**, reducing the risk of content gaps and downtime.