# Simulated devices

> Add a device that produces values on the gateway itself, to try trends, rules, pipelines and dashboards without a real machine.

Source: https://proxus.io/docs/connect/devices/simulator

At the end of this guide, a simulated device sends values like a real machine: a temperature that swings, a
speed that drifts, a running signal that turns on and off. Use it to build and test trends, rules, pipelines and
dashboards before the real machine is connected, or for a demo.

The **Simulator** protocol runs on the gateway itself. There is no address to reach and nothing to install.

## Before you start

You need a gateway that is online. The hub's own gateway, **SYSTEM**, works.

## Add a simulated device

Follow [Add a device](https://proxus.io/docs/connect/devices/add-a-device), with these differences.

### Step 1: Protocol and gateway

Type `simulator` in the protocol search box and select the **Simulator** card.

### Step 2: Connection

*Screenshot: The connection step for the simulator with only the Read every field and a passed test*

1. **Read every**: how often the gateway produces a new value for each tag. Leave **Profile default** or choose an
   interval.
2. **Test the connection** is optional. It only confirms that the gateway is ready to produce values.

### Step 3: Tags

For the simulator, a tag's **Address** is the range the value stays in, and the **Pattern** column says how the
value moves inside that range.

*Screenshot: The simulator tag table with three tags: OvenTemp with a sine wave, BeltSpeed with a random walk and Running with a square wave, each with a test value*

1. The tabs to add tags. **Paste** also takes a fifth column with the pattern name.
2. The tag table: **Name**, **Address**, **Type**, **Unit**, **Pattern** and the **Test read** value.
3. **Pattern** of each tag. See [Patterns](#patterns).
4. **Read all once** produces one value for each tag, so you can check the ranges.

The quickest way to add tags is the **Address helper** under the table:

*Screenshot: The address helper with name BatchCount, minimum 0, maximum 5000, unit pcs, type Int and the cycle pattern, building the address [0,5000]*

1. **Minimum** and **Maximum**: the range of the value.
2. **Pattern**: how the value moves.
3. The address the helper builds, for example `[0,5000]`.
4. **Add to the list** adds the tag to the table.

Fill in **Name**, **Unit** and **Type** as well. Then continue with **Place and type** and **Save and verify** as for
any device.

## Addresses

| Address | Meaning | Example |
| --- | --- | --- |
| `[min,max]` | A value between `min` and `max`. Use a full stop for decimals. | `[180,220]`, `[-5.5,40]` |
| `model:Asset/Signal` | A signal of the demo plant model. The value follows the plant's simulated production, with stops, faults and changeovers. | `model:LYS.P1.CSP/Speed` |
| `model:{device}/Signal` | The same, for the asset whose device name is the device's own. Used by the demo profiles, so one profile serves every machine of a kind. | `model:{device}/GoodCount` |

A text tag (type String) may have an empty address. It then gets a random text of ten letters and digits. A
**Bool** tag is `true` when its value is above 0, so `[0,1]` with **Square wave (on/off)** gives a running signal.
A **DateTime** tag gets a random date in the last year.

> **Note:**
`model:` addresses and `{device}` work only with the assets and device names of the demo plant model that comes
with the demo data (for example `MFB_LYS_P1_CASEPACKER`). For a device of your own, use a `[min,max]` range.

## Patterns

| Pattern | How the value moves |
| --- | --- |
| **Random** | A new random value in the range at each read. |
| **Random walk** | Small steps up or down from the middle of the range. |
| **Sine wave** | A smooth wave between minimum and maximum. |
| **Triangle wave** | Rises and falls in straight lines. |
| **Sawtooth** | Rises in a straight line, then drops back. |
| **Square wave (on/off)** | Stays at the maximum, then at the minimum, for equal times. |
| **Steps** | Moves in ten steps through the range. |
| **Around the middle (Gaussian)** | Random, mostly near the middle of the range. |
| **Smoothed noise** | Random, but without sudden jumps. |
| **Cycle (ramp, hold, fall)** | Ramps up, holds, then falls, like a machine cycle. |
| **Composite (wave and noise)** | A wave with noise on top. |
| **Plant model** | Follows the demo plant model. Required for a `model:` address. |

Without a pattern, a `[min,max]` tag uses **Random** and a `model:` tag uses **Plant model**.

## What's next

- [The device page](https://proxus.io/docs/connect/devices/device-page): watch the simulated values and open their trends.
- [Rules](https://proxus.io/docs/automate/rules): try an alarm on a simulated value.
- [Your first machine](https://proxus.io/docs/get-started/first-machine): the guided tutorial that uses the simulator.