Documentation

Insert - Testpoint

5 min read

Use this to insert a testpoint into a PCB or Schematics Design.

Shortcuts

Default Keys: None

Default Menu: Insert

Command: Insert Testpoint

Locating this option

Available from: Insert menu > Testpoint option

What Is A Testpoint

A testpoint is an item on a net in the PCB design that, once the board has been made, can be physically probed to test the signal at that point. These testpoints have names and a copper pad on the side of the board that can be tested.

In Pulsonix, testpoints can be any of the following:-

  • Existing items on the board can be tested. Component Pads, Vias or Mounting Holes that are on the test probe side can be allocated a testpoint name.
  • New, stand alone testpoint pads can be added to nets to provide copper points from which signals can be tested. These can be free pads, vias or single pad documentation symbols (if a documentation outline is required).
  • Testpoint Parts can be added if the testpoint is a physical device that needs to be inserted onto the board after it has been made.

All of these types of testpoint can be added using the Insert Testpoint option detailed below. At any stage a testpoint can be found using the Find option on the Edit menu.

Schematics Designs

Testpoints can be inserted into the Schematics design, either just as documentation, or as part of the engineer driven design process whereby the testpoints will be created on the correct nets when the design is transferred to a PCB design. Also if the design needs testpoint parts, these can be inserted at the schematics design stage.

Testpoint Rules

The side that the finished board can be probed from can be set up in the Design Rules in the Technology data. This helps avoid mistakes as only items that are on the test probe side can be turned into testpoints. The testpoint grid can also be set up in these rules. Some boards use a ‘bed of nails’ test rig where the test probes are on a set grid. By using the testpoint grid, moving any testpoint keeps it on this grid, and if any item is turned into a testpoint a warning is given if it is not on the grid.

Testpoint Report

A report can be generated from the PCB showing the names and locations of the testpoints. Any testpoints that are in error (on the wrong side or not on the grid) are reported in this.

How To Insert A Testpoint

The basic procedure is to enter Insert Testpoint mode, select an item on a net you wish to probe near (a new testpoint will be added), place the testpoint in it’s correct position. The procedure in more detail follows:-

  1. Select the Insert Testpoint icon from the Toolbar, or from the Insert menu, select the Testpoint option.
  2. If a pad, via or mounting hole is already pre-selected you are in ‘single shot’ mode. The testpoint will be connected to this item. If not in single shot mode you will be prompted to click on a net item to connect the new testpoint to. Once an item has been chosen (by either method) it is shown on the status bar and the process enters its second stage.
  3. A testpoint will be added and attached to the end of the cursor for you to position using the mouse. The initial type of this testpoint (pad, via, doc symbol or part) is determined by the setting in the Testpoint Defaults section within Design Settings.
  4. At this point, right click to use the shortcut menu to change the testpoint type and other properties.
    • Change Layer - to swap the testpoint to the other side of the board. Only available if the DFM Rules state that the board can be tested on both sides.
    • Change Name - to use a different name to the one automatically allocated.
    • Change Type - choose one of the four types (pad, via, doc symbol or part). The current one being used will be ticked.
    • Change Testpoint Symbol - use this if you are adding a testpoint Documentation symbol or part. It will enter the Change Testpoint Symbol dialog that allows you to change which symbol or Part you are using from the library.
    • Online DRC - to restrict positioning of the testpoint to conform with the design rules settings within the Technology data.
    • Display Clearance - to present a visible warning if you are positioning a testpoint too close to another item within the design.
    • Change Grid - To change the grid step, or work with no grid.
  5. There are three ways to finish adding the testpoints as follows:
    • Click in space to drop the new testpoint into its correct position in the design. A connection will be added from the testpoint to the picked item, which may be routed later.
    • Click on a pad, via or mounting hole on the same net to turn the picked item into a testpoint. The testpoint that was being moved around will be removed. A quick way of doing this is to Double-Click on the item just after entering Insert Testpoint. The first click starts the process, and the second completes it.
    • Click on a track on the same net to insert the testpoint into the track at the gridded pick position.
  6. If in single shot mode, the process will be ended after the addition of the single testpoint. If not, then you will prompted to pick the next item to add a testpoint to. Press the Escape key to exit Insert Testpoint mode.

Change Grid | Change Name | Change Symbol | Change Testpoint | Testpoint Defaults | Display Clearance | Find | Online DRC | Properties | Testpoint Grid | Testpoint & Testability Reports | Technology - Testpoint Rules | Automatic Testpoint Insertion

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