# 04 Advanced Variables

In this tutorial you'll build a dashboard that shows OEE metrics and production runs per machine. Panels repeat automatically for each selected machine:

<figure><img src="https://4261006941-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSNEuiyRRKwuqtIcaEt45%2Fuploads%2Fgit-blob-1d02cb6435c4484ea403b77ede8746ea9a41e15a%2Fgrafana-var-adv-hero-01.png?alt=media" alt=""><figcaption></figcaption></figure>

## What you'll learn

* Multi-select and "Include All" for variables
* Automatically repeating panels (Repeat)
* Hidden variables for time rounding (OEE API)
* Per-machine OEE with POST queries
* Brief overview: time series data via the API

## Prerequisites

* [Working with Variables](https://docs.enlyze.com/en/integrations/grafana/advanced-api/03-variables) completed
* Understanding of dashboard variables, JSONata, and API queries

***

## Multi-select and Include All

In [Part 1](https://docs.enlyze.com/en/integrations/grafana/advanced-api/03-variables) the `machine` variable held a single value. For a dashboard showing multiple machines at once, you need multi-select.

1. Create a new dashboard with a `site` variable as in Part 1
2. Create a variable `machines` (plural) with these settings:

| Setting       | Value      |
| ------------- | ---------- |
| Variable type | Query      |
| Name          | `machines` |
| Label         | Machine    |
| URL           | `machines` |
| Root selector | `$.data`   |

3. Add under **URL Query Params**:

| Key    | Value     |
| ------ | --------- |
| `site` | `${site}` |

4. Columns: `name` (Name), `uuid` (UUID)
5. Under **Selection options**:
   * Enable **Multi-value**
   * Enable **Include All option**
   * **Sort**: Alphabetical (asc)
   * **Refresh**: On dashboard load

You can now select individual machines from the dropdown or choose **All** for every machine at the site.

{% hint style="info" %}
Note the variable name `machines` (plural). This signals that the variable can hold multiple values and avoids confusion with the single-value `machine` variable from Part 1.
{% endhint %}

***

## Repeating panels (Repeat)

Instead of creating separate panels for each machine, let Grafana repeat panels automatically.

### Configure a row with Repeat

1. Create a **Row** (click **Add** > **Row**)
2. Click the gear icon on the row
3. Set **Title** to `${machines:text}`
4. Under **Repeat for**: select the `machines` variable

Grafana now creates a separate row for each value of the `machines` variable. Within each row, `${machines}` is replaced by the UUID of the respective machine.

<figure><img src="https://4261006941-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSNEuiyRRKwuqtIcaEt45%2Fuploads%2Fgit-blob-1d02cb6435c4484ea403b77ede8746ea9a41e15a%2Fgrafana-var-adv-hero-01.png?alt=media" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
Panels inside a repeat row automatically use the current iteration value. While `${machines}` normally contains multiple UUIDs, inside a repeat row it resolves to exactly one UUID per iteration.
{% endhint %}

{% hint style="warning" %}
You can only edit the **first** repeated element — whether row or panel. The remaining copies are automatically regenerated from the first element on every refresh.
{% endhint %}

***

## Hidden variables: time rounding for OEE

The `productivity-metrics` endpoint expects timestamps aligned to 10-minute intervals. Grafana's built-in time variables (`${__from}`, `${__to}`) return arbitrary timestamps. The solution: custom variables that round the selected time range to 10-minute intervals. Since these variables are only relevant for queries, they are implemented as **hidden variables** — they don't appear as dropdowns in the dashboard. If needed, you can include their value using `${start}` or `${end}` in panel titles for transparency.

### Create the start variable

1. Open **Dashboard Settings** > **Variables** > **+ New variable**
2. Configure:

| Setting       | Value                       |
| ------------- | --------------------------- |
| Variable type | Query                       |
| Name          | `start`                     |
| Hide          | **Variable** (fully hidden) |
| Source        | Inline                      |
| Data          | `{"time": ${__from}}`       |
| Root selector | see below                   |
| Refresh       | **On time range change**    |

3. Root selector (JSONata expression):

```
(
  $time_millis := $number($.time);
  $time_rounded := $time_millis - $time_millis % 600000;
  $fromMillis($time_rounded)
)
```

`600000` milliseconds = 10 minutes. The formula rounds the timestamp down to the nearest 10-minute interval.

### Create the end variable

Create a second hidden variable `end` with the same settings, but:

| Setting | Value               |
| ------- | ------------------- |
| Name    | `end`               |
| Data    | `{"time": ${__to}}` |

{% hint style="info" %}
**Refresh: On time range change** is critical here. Without this setting, `start` and `end` would only be calculated when the dashboard loads and wouldn't update when you change the time range.
{% endhint %}

***

## Per-machine OEE with Repeat

Now you'll combine repeat rows with the `productivity-metrics` endpoint.

### OEE Stat panel

Create a **Stat** panel inside the repeat row:

| Setting       | Value                                       |
| ------------- | ------------------------------------------- |
| Method        | POST                                        |
| URL           | `machines/${machines}/productivity-metrics` |
| Root selector | `$.data`                                    |

Expand **Parsing options & Result fields** and add a **Column**:

| Selector             | Title        | Type   |
| -------------------- | ------------ | ------ |
| `productivity.score` | productivity | Number |

Expand **URL options** and configure the request body:

| Setting           | Value                                                           |
| ----------------- | --------------------------------------------------------------- |
| Body Type         | Raw                                                             |
| Body Content Type | **JSON**                                                        |
| Body Content      | `{"datetime_ranges": [{"start": "${start}", "end": "${end}"}]}` |

{% hint style="warning" %}
Make sure **Body Content Type** is set to **JSON** (not Text). The ENLYZE API rejects requests with `Content-Type: text/plain` (HTTP 422).
{% endhint %}

Configure the panel:

* **Unit**: Percent (0.0-1.0)
* **Color mode**: Background
* **Thresholds**: Red (base), Yellow (0.6), Green (0.8)
* **Value Mapping**: `null` → "NO DATA" (Grey)

### Why Columns instead of Root Selector?

It would be tempting to extract the score directly in the root selector, e.g. `$.data[0].productivity.score`. This works as long as the API returns data. However, if a machine wasn't running during the selected time range, `$.data` is an empty array. Accessing `[0]` then fails and Grafana shows an error instead of an empty panel.

The solution: set the root selector to `$.data` and extract the value via a **Column** (`productivity.score`). If there's no data, the column returns `null`. You can then display this `null` value as "NO DATA" using a **Value Mapping**.

### Additional OEE panels

Create panels for the remaining metrics using the same pattern:

| Panel        | Root selector | Column Selector      |
| ------------ | ------------- | -------------------- |
| Availability | `$.data`      | `availability.score` |
| Performance  | `$.data`      | `performance.score`  |
| Quality      | `$.data`      | `quality.score`      |

Configure a value mapping for `null` → "NO DATA" in grey on all panels. Not all machines provide quality data, and machines without production in the selected time range show "NO DATA" for all metrics.

<figure><img src="https://4261006941-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSNEuiyRRKwuqtIcaEt45%2Fuploads%2Fgit-blob-bec7f086ee21655ee70645029b1aa6c545d482ad%2Fgrafana-var-adv-oee-row-01.png?alt=media" alt=""><figcaption></figcaption></figure>

### Production runs table

Add a **Table** to the row showing the production runs for the respective machine:

| Setting       | Value                                                                     |
| ------------- | ------------------------------------------------------------------------- |
| Method        | GET                                                                       |
| URL           | `production-runs`                                                         |
| Query Params  | `machine=${machines}`, `start=${__from:date:iso}`, `end=${__to:date:iso}` |
| Root selector | `$.data`                                                                  |

Add columns: `start` (Start, Timestamp), `end` (End, Timestamp), `production_order` (Order, String), `productivity.score` (OEE, Number).

***

## Excursus: time series data via the API

For time series data (e.g. temperature curves, throughput) the ENLYZE API offers the `timeseries` endpoint:

```json
POST /timeseries
{
  "machine": "uuid",
  "start": "2025-12-08T00:00:00Z",
  "end": "2025-12-09T00:00:00Z",
  "variables": ["variable-uuid-1", "variable-uuid-2"],
  "resampling_interval": 60
}
```

The `resampling_interval` parameter (in seconds) reduces the data volume. Without resampling, queries can return very large datasets.

**Limitations:**

* The API paginates responses (max 100 entries per page). The Infinity plugin only supports automatic pagination experimentally.
* For time series visualizations, the ENLYZE data source (the dedicated Grafana plugin) is the better choice, as it handles pagination and resampling automatically.

***

## Tips

* **Variable Refresh**: "On dashboard load" for master data (sites, machines). "On time range change" for time-dependent calculations like the rounded timestamps.
* **Variable order**: The order in Settings determines the evaluation order: `site` → `machines` → `start` → `end`.
* **Debugging Repeat**: If repeat panels don't appear, check that the variable is correctly selected under **Repeat options** on the row and that it contains multiple values.
* **POST Body**: The body is specified as a string. Variables like `${start}` are replaced before sending. Ensure correct JSON syntax with quotes.

***

## Next steps

* [**Production Status Dashboard**](https://docs.enlyze.com/en/integrations/grafana/production-dashboards/04-production-status) — Constant variables and live status displays for multiple machines