Desktop

# Explore the sample project

> Run a simulated tank pressurization test, take control of a valve, and abort the test.

The sample project is a simulated tank test. A nitrogen supply fills the tank through the press valve, and the vent valve empties it. An Arc automation pressurizes the tank, holds it, and vents it. You watch the test on a schematic and a line plot, take control of a valve, and abort the test. You need no hardware, and the tutorial takes about five minutes.

You need [Synnax Desktop](https://docs.synnaxlabs.com/reference/get-started/install-desktop).

## Step 1Open the sample project

If the list of projects is empty, select **Open sample project**. If you already have projects, open one and run the “Open sample project” command from the [command palette](https://docs.synnaxlabs.com/reference/get-started/ui-overview#search-and-command-palette).

If the sample project already exists, the Console asks whether to reset it. A reset removes your changes to the sample project and its Arc automations, so you can use it to start again.

The Console creates a project with:

| Item           | Kind                                                                    | What it does                                                                        |
| -------------- | ----------------------------------------------------------------------- | ----------------------------------------------------------------------------------- |
| Tank           | [Schematic](https://docs.synnaxlabs.com/reference/visualize/schematics) | Shows the tank, its valves, and its pressure, with **Start** and **Abort** buttons. |
| Tank pressure  | [Line plot](https://docs.synnaxlabs.com/reference/visualize/line-plots) | Plots the tank pressure, and the state of each valve.                               |
| Press sequence | [Arc automation](https://docs.synnaxlabs.com/reference/control/arc)     | Runs the test: pressurize, hold, and vent.                                          |
| Tank simulator | Arc automation                                                          | Simulates the tank. It writes the pressure from the valve commands.                 |

Both Arc automations start at once. The tank pressure is 0 psi, and both valves are closed.

[](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/get-started/sample-project/open-dark.mp4#t=0.001)

## Step 2Run the test

On the Tank schematic, click **Start**.

The Press sequence opens the press valve, and the pressure climbs on the line plot. At 300 psi, the sequence closes the press valve and holds for 10 seconds. Then it opens the vent valve until the pressure is below 5 psi, and waits for the next start.

[](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/get-started/sample-project/run-test-dark.mp4#t=0.001)

## Step 3Take control of a valve

The Press sequence has a higher [control authority](https://docs.synnaxlabs.com/reference/control/authority) (100) than the Tank schematic (1), so a click on a valve has no effect while the sequence runs. To take a valve from the sequence, click its control chip. The chip takes control at 255, the highest authority.

1. Click the control chip next to **Vent valve**. The chip turns green.
2. Click **Vent valve**. The vent valve opens.
3. Click **Start**. The Press sequence opens the press valve, but its command to close the vent valve has no effect. The pressure stops near 140 psi, because the gas goes out through the vent valve as fast as it comes in.
4. Click **Vent valve** to close it. The pressure climbs again.
5. Click the green chip to give the vent valve back. The test continues as in step 2.

The control chip next to each valve shows which writer has control. Hover over a chip to see a description. For more, see [manual control](https://docs.synnaxlabs.com/reference/control/manual).

[](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/get-started/sample-project/take-control-dark.mp4#t=0.001)

## Step 4Abort the test

1. Click **Start**.
2. Before the hold ends, click **Abort**.

The Press sequence closes the press valve and opens the vent valve. In the abort stage, the sequence raises its authority to 255, the same as a control chip, so its commands also reach a valve that an operator holds. See [virtual channels](https://docs.synnaxlabs.com/reference/control/authority#virtual-channels). The sequence also aborts by itself when the pressure goes above 450 psi.

To run the test again after an abort, click **Start**.

[](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/get-started/sample-project/abort-dark.mp4#t=0.001)

## Step 5Read the Press sequence

The Press sequence tab on the right shows its code. The sequence has five [stages](https://docs.synnaxlabs.com/reference/control/arc/execution-model#steps-of-a-sequence). It is in one stage at a time, and it moves to the next stage when a condition is true.

| Stage        | What it does                                                           | Moves to                                                     |
| ------------ | ---------------------------------------------------------------------- | ------------------------------------------------------------ |
| `idle`       | Closes both valves.                                                    | `pressurize` on **Start**.                                   |
| `pressurize` | Takes authority 100, and opens the press valve.                        | `hold` above 300 psi; `abort` above 450 psi or on **Abort**. |
| `hold`       | Closes the press valve.                                                | `vent` after 10 seconds; `abort` on **Abort**.               |
| `vent`       | Opens the vent valve.                                                  | `idle` below 5 psi.                                          |
| `abort`      | Closes the press valve, opens the vent valve, and takes authority 255. | `pressurize` on **Start**.                                   |

To learn to write a sequence like this one, see [test sequences](https://docs.synnaxlabs.com/reference/control/arc/test-sequences).

## Next steps

* Build your own channels, Arc automation, plot, and range in [your first run](https://docs.synnaxlabs.com/reference/get-started/first-run).
* Learn the words the docs use in [Synnax concepts](https://docs.synnaxlabs.com/reference/get-started/concepts).
* Connect real hardware with a [task](https://docs.synnaxlabs.com/reference/hardware/tasks).