Altium Designer can generate a test point report — a CSV listing every designated test point on your board with its net name, coordinates, and layer. Fixture vendors use this data to place probes in a bed-of-nails fixture that match your PCB layout exactly. Here's how to export one and format it for your vendor.
Before you start#
You need:
- Altium Designer (any recent version with Assembly Output support)
- A PCB layout with test points designated — pads or vias must have their Testpoint property set in the Properties panel
- A defined board origin — the coordinate reference point your fixture vendor uses to align probes
Need to add test points first?
In the PCB editor, select a pad, open Properties, and set Testpoint to Top or Bottom. Use Find Similar Objects to bulk-assign across matching pads. See Altium's test point documentation for the full workflow.
Designating test points in bulk#
Marking test points one pad at a time is slow. Altium's Find Similar Objects feature lets you apply test point settings across every matching pad at once.
- Right-click a pad that represents the test point geometry you want to designate.
- Select Find Similar Objects.
- Set Hole Size to "Same" for through-hole pads. Set X Size and Y Size to "Same" to match pad dimensions.
- Check Select Matching and Open Properties at the bottom of the dialog.
- Click OK. All matching pads are now selected.
- In the Properties panel, find the Test Point section and set Assembly to your target layer — Top, Bottom, or Both.
Every matching pad on your board is now designated as a test point.
Generating the test point report#
- Start the test point export: go to File → Assembly Outputs → Test Point Report.
- Configure the export settings:
| Setting | Value |
|---|---|
| Report Format | CSV |
| Test Point Layers | Top Layer and Bottom Layer |
| Units | Metric |
| Coordinate Positions | Reference to relative origin |
- Click OK.
Altium saves a .csv file in your project's output directory.
Understanding the output#
The generated CSV contains one row per test point with these columns:
| Column | What it means | Fixture design use |
|---|---|---|
| Net | Net name (GND, VCC, SDA) | Maps probes to electrical nodes |
| Name | Pad or via designator | Identifies the physical component |
| X | X coordinate in chosen units | Probe X placement |
| Y | Y coordinate in chosen units | Probe Y placement |
| Side | Top or Bottom layer | Determines which fixture plate |
| Hole Size | Through-hole diameter (0 for SMD) | Affects probe selection |
| Type | Pad type (TH, SMD) | Informational |
Net, X, Y, and Side are the four columns that matter most. Fixture design tools use them to generate a probe plate model automatically.
Formatting for FixturFab Studio#
If you followed the export settings above — CSV format, metric units, relative origin — your Altium output should work directly with Studio's test point CSV upload.
Before uploading, verify:
- Units match. Studio expects metric. If you exported in mils, re-export rather than converting manually — it avoids rounding errors.
- Origin is consistent. The relative origin in your PCB layout should match your intended fixture reference point.
- Both layers are included. If your board has test points on top and bottom, confirm both layers exported.
For the exact CSV format specification, see the Studio test point CSV documentation.
Troubleshooting#
Test points missing from the report. The most common cause: pads aren't actually designated as test points. Select the pad and check the Properties panel — Testpoint must be set to Top or Bottom, not None. Vias can be test points too, but need explicit designation.
Coordinates look wrong. Check your board origin. Go to Edit → Origin → Set and verify the relative origin is where you expect. Fixture vendors need coordinates relative to a known reference point, not Altium's absolute origin.
Top/Bottom layer confusion. Altium reports the layer the pad is on, not the side you're probing from. Through-hole test points appear on both sides — the report reflects the layer assignment in your design.
Units mismatch. If your report shows mils but your vendor expects millimeters, re-export with Units set to Metric. Don't convert manually.
Next steps#
You have a test point report. Now use it.
Upload to Studio for DFT analysis
Drop your test point CSV into Studio to check probe spacing, identify access issues, and get your fixture quote.
For background on where to place test points and how many you need, see the design for test guide.