# Graph editor > Build an Arc automation from blocks in the Console, such as an alarm on a channel. ![](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/control/arc/graph-editor/hero/3f324c0c91ec/window-light.webp) In the graph editor, you build an Arc automation from blocks instead of code. Each block reads a channel, holds a value, compares values, or sets a status. You connect the blocks with lines, and values move along the lines from left to right. Use the graph editor for simple automations, such as alarms. For sequences and functions, use the text editor. See [text and graph editors](https://docs.synnaxlabs.com/reference/control/arc#text-and-graph-editors). ## Build an alarm This alarm sets a status to a warning when `tank_pt` goes above 450, and back to success when it goes below. Before you start, [create a status](https://docs.synnaxlabs.com/reference/alarms/statuses#set-a-status), such as `Tank pressure`. 1. [Create an Arc automation](https://docs.synnaxlabs.com/reference/control/arc/automations#create-an-arc-automation) with **Graph** as the **Editor mode**. 2. In the **Stages** tab of the toolbar, drag these blocks onto the graph: * **Telemetry source**, from **Telemetry**. * **Constant**, from **Basic**. * **Greater than**, from **Operators**. * **Select**, from **Flow control**. * Two **Change status** blocks, from **Basic**. 3. Click each block and set its fields in the **Properties** tab: * For **Telemetry source**, set **Channel** to `tank_pt`. * For **Constant**, set **Value** to `450`. * For the first **Change status**, set **Status** to `Tank pressure`, **Variant** to **Warning**, and **Message** to `Tank pressure is above 450 psi`. * For the second **Change status**, set **Status** to `Tank pressure`, **Variant** to **Success**, and **Message** to `Tank pressure is normal`. 4. Connect the blocks. Drag from the handle on the right of a block to a handle on the left of the next block: * **Telemetry source** to the top input of **Greater than**. * **Constant** to the bottom input of **Greater than**. * **Greater than** to **Select**. * The `true` output of **Select** to the warning **Change status**. * The `false` output of **Select** to the success **Change status**. 5. [Choose where it runs](https://docs.synnaxlabs.com/reference/control/arc/automations#choose-where-it-runs), then click **Start**. When `tank_pt` goes above 450, the status changes to a warning. When it goes back to 450 or below, the status changes to success. See [alarms](https://docs.synnaxlabs.com/reference/alarms) for how operators see statuses. [](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/control/arc/graph-editor/build-alarm-dark.mp4#t=0.001) The top input of an operator block decides when the block runs. Connect the channel to the top input, and the constant to the bottom input. If the channel goes to the bottom input, the block runs only once. ## Edit the graph * **Add a block** -> drag it from the **Stages** tab to where you want it. A click adds it at the top left of the graph. * **Select blocks** -> click a block. Hold **Shift** to select more than one, or press **Ctrl+A** (**Cmd+A** on macOS) to select all. Press **Esc** to clear the selection. * **Align blocks** -> select two or more blocks, then use the **Align** buttons in the **Properties** tab. * **Delete** -> select blocks or lines, then press **Backspace** or **Delete**. * **Copy and paste** -> press **Ctrl+C** and **Ctrl+V** (**Cmd+C** and **Cmd+V** on macOS), or right-click the graph. * **Stop editing** -> right-click the graph and select **Disable editing**. The **Stages** and **Properties** tabs show only while editing is on. The editor lets you connect any two handles. The compiler reports a connection that does not fit when you start the automation. ## Blocks | Group | Block | What it does | In text mode | | ------------ | ------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------- | -------------------------------- | | Basic | **Constant** | Sends its **Value**. | A number, such as `450` | | Basic | **Change status** | Sets the **Status** to its **Variant** and **Message** each time a value arrives. | `status.set{...}` | | Telemetry | **Telemetry source** | Sends each new value of its **Channel**. | A channel name | | Telemetry | **Telemetry sink** | Writes each value that arrives to its **Channel**. | `-> channel` | | Operators | **Greater than**, **Less than**, **Equal**, **Not equal**, **Greater than or equal**, **Less than or equal** | Compares the top input with the bottom input, and sends true or false. | `>`, `<`, `==`, `!=`, `>=`, `<=` | | Operators | **And**, **Or** | Sends true or false from two true or false inputs. | `and`, `or` | | Flow control | **Select** | Sends each true value from its `true` output, and each false value from its `false` output. | `select{}` | | Flow control | **Stable for** | Sends a value only after the value stays the same for its **Duration**, in seconds. | `stable.for{duration=...}` | See the [standard library](https://docs.synnaxlabs.com/reference/control/arc/standard-library) for [`status`](https://docs.synnaxlabs.com/reference/control/arc/standard-library/status), [`select`](https://docs.synnaxlabs.com/reference/control/arc/standard-library/select), and [`stable`](https://docs.synnaxlabs.com/reference/control/arc/standard-library/stable). ## Limits * A graph has no sequences or stages. All of its blocks run at the same time. * A graph cannot set control authority, keep variables, or call functions. * The **Add**, **Subtract**, **Multiply**, **Divide**, and **Not** blocks cause a compile error. Use the text editor for math. * You cannot change a graph automation into a text automation.