3. Compass Entry Selection — Standard Cartesian
In this step the Compass entry on which the standard Cartesian widget will run is selected. For the Cartesian flow, the entry must return at least two columns (X axis + Y value); if multi-series will be used, columns will be mapped in step 6.
Wizard route: /cartography/add/selectcompass
Prerequisite
Steps 1 (Cartesian) and 2 (Line/Area/Spline/Column/Bar/Step Line) must be completed. There must be at least one saved entry in Compass.
If there is no entry in Compass: → Compass
1. Compass Entry List Loads
When you enter the step, the Compass entry list loads automatically. The list contains the following columns:
| Column | Description |
|---|---|
| Name | Compass entry name |
| Description | Description of the entry |
| Datasource | Connected data source type (SQL / MQTT / REST / Excel) |
| Tags | Tags assigned to the entry |
2. Data Sources Suitable for Standard Cartesian
All Compass entry types can be used for standard Cartesian; however, each has different advantages.
| Data Source | Suitability for Standard Cartesian | Notes |
|---|---|---|
| PostgreSQL / MSSQL / MySQL (SQL) | ✅ Ideal | Sorted X axis is prepared with GROUP BY + ORDER BY |
| REST API | ✅ Suitable | JSON response is converted to array columns |
| MQTT | ⚠️ Limited | Instant snapshot returns a single row; TimescaleDB is preferred for trends |
| Excel Offline | ✅ Suitable | The first row of the sheet is taken as the header; Sheet additional dropdown appears in sub-step 5 |
Sorting on the X Axis
Your query must return the X axis column sorted. In SQL use ORDER BY ts ASC, in REST the array order returned from the API is used, in Excel the row order in the sheet is used. Otherwise, in Line/Area/Spline charts, the line zigzags back and forth.
Y Column Must Be Numeric
Only a numeric column can be bound to the standard Cartesian Y axis. Add value::NUMERIC cast or CAST(value AS DECIMAL) on the SQL side. If string numbers are returned from the REST response, convert them to Number in the post-processing stage of the Compass entry.
3. Search Entry
The text you type into the search box applies a live filter on entry name and description.
Tip
If you name your entries on the Compass side in facility_line_type format (e.g., facility1_line3_hourly_production), you find them here in seconds.
4. Tag Filter
When you click the filter icon at the top of the list, you can select from all tags in the panel that opens from the right. Only tags actually used in Compass entries appear in the list — unused tags do not appear in this list.
| Action | Effect |
|---|---|
| Select a tag | Only entries containing that tag remain |
| Select multiple tags | Entries containing all of them remain (AND logic) |
| Clear | Removes all tag filters |
5. Confirm the Entry
When an entry is clicked, the row is highlighted. Proceed with the Next button at the top right.
Proceeding Without Entry Selection
If no entry is selected, Next issues a warning: "Please select a Compass query first". (Although the UI text says "query", the selected item can be any Compass entry.)
6. Excel Offline Special Case
If the data source of the entry you selected is Excel Offline, an additional sheet selection is required. When the entry row is selected, a Sheet dropdown appears below it.
| Step | Description |
|---|---|
| 1 | Select the Excel entry |
| 2 | Select a sheet name from the opened sheet list |
| 3 | Next |
If a Sheet Is Not Selected
If an Excel entry is selected but no sheet is selected, Next issues a warning: "Please select an Excel sheet first".
7. Preview Run
When the Next button is pressed, the entry is run once so the widget's axis / column mapping can be set up correctly, and the result is held in memory.
| Data Source | Operation |
|---|---|
| SQL (PostgreSQL/MSSQL/MySQL) | Query runs directly on the database |
| MQTT | An instant message snapshot is taken from the topic |
| REST API | An HTTP request is made to the endpoint |
| Excel Offline | The sheet is read and cells are converted to an array |
ESC During Loading
If the operation takes a long time, you can cancel with the Esc key. After cancellation, you return to entry selection.
8. Common Errors
| Symptom | Possible Cause | Solution |
|---|---|---|
| Entry list is empty | No entries exist in Compass or you have no permission | Create entries in Compass → Compass |
| The entry I am looking for does not appear | Tag filter may be active | Clear it from the filter panel with Clear |
| Sheet list is empty in Excel | The file is corrupted or consists of empty sheets | Check the Excel file in Port |
| Spinning for a long time on Next | SQL query is slow, REST endpoint not responding | Test the entry in Compass, add LIMIT if needed |
| No numeric Y axis column error (in next step) | Query does not return a numeric column | Add CAST(value AS NUMERIC) in SQL |