Inspecting Fabrication Data with the CAM Editor in Altium NEXUS

Altium NEXUS's CAMtastic Editor (CAM) offers a variety of tools, the most basic of which are for viewing and editing CAM data. Once image and drill files have been imported, the CAM Editor can receive instructions determining layer types and stackup, at which point a netlist can be extracted and compared with an IPC netlist generated from the original PCB design software. These netlists will handle not just through-hole components, but blind and buried vias as well. The CAM Editor also offers Design Rule Checking, panelization, and NC-Routing (plus milling) tools.

CAM Action Basics

The CAM Editor environment utilizes some slightly different methods for performing actions and procedures than you may be accustomed to.

Action Before Selection

The way actions are performed within the CAM Editor may seem backward to new users who are used to selecting objects before telling the program what to do to them. Similar to other CAM tools, the CAM Editor reverses this process: first, you choose the action, then you select the objects to act upon, finishing with an execute command.

If this is not the way you are used to working, then you can lean on a couple of crutches until you find your footing. First, look at the cursor. When it displays as a cross-hair target over the design workspace, that means it's not in selection mode (a square pick-box cursor is displayed during selection mode). The fact that the selection buttons are all grayed-out can remind you that you haven't picked an action yet; at least not one that calls for general selections. The status bar, which is located at the bottom of the main editing window, is particularly helpful during multi-step processes when you're wondering why nothing is happening; the status bar will let you what the CAM Editor is waiting for you to do.

Right-click Execution

First, you choose a command, then you select a set of objects. After this, the CAM Editor waits for an execution command. This gives you the freedom to carefully construct your selection over various layers and groups of objects. The basic way to send the execute command is by right-clicking.

You may notice that after you have executed a function the cursor does not return to its inactive state. Instead, the selection pick box remains, and the status bar prompts you to start selecting again. This happens when the Auto Repeat Functions option is enabled on the CAM Editor - General page of the Preferences dialog.

The right-click button can sometimes be used to cancel current processes. This works when you have not yet completed a required step, such as selecting objects. The Esc key, however, is a safer button to press for cancellations in general.

Editing Modes

The CAM Editor supports two editing modes: CAM and NC (Routing). The modes are enabled using the respective CAM Editor and NC Editor commands available when selecting View » Cam Editor or View » NC Editor from the main menu. Alternatively, you can set the editing mode directly from the drop-down available in the CAMtastic panel. Essentially, these modes differ in how the data is displayed. The CAM Editor mode will show you images exactly as they will be drawn or flashed onto the photographic film, which will be used in PCB manufacture. The NC Editor mode adds markers to drill holes and rout paths.

A rout path shown in NC Editor mode.

The CAM Editor will always be in one of these two editing modes. While in CAM Editor mode, the routing tools will be grayed out in the menus. Likewise, when the NC Editor mode is active, the normal CAM editing tools are disabled. When the CAM Editor mode is active, the CAMtastic panel will give you quick access to the DCodes defined in the Aperture List through a drop-down list. When the NC Editor mode is active, this drop-down shows the set of tools for drilling, routing, and milling instead. Most importantly, the design space will correspond with the current editing mode. The NC Editor mode denotes drill points and routing paths with special markers: each drill point is marked with an X, while routing paths contain plunge and retract points and, when necessary, direction markers as well. These instruction markers are invisible when working in CAM Editor mode.

The CAMtastic Panel

The panel, which is available whenever a CAM document is active, contains the salient information for that CAM document, including the layers, the current Dcode or tool bit, grid/unit settings, and the absolute location of the cursor within the design space. You can also alternate focus between the Info, DRC, Nets, and Steps regions of the panel for other design-specific information.

The Layers region shows all created/imported layers and their visibility status. The current layer will have a white X through its associated color swatch and is also reported at the top of the region. You can double-click on another layer's name to make it the current layer.

Right-clicking anywhere in this region gives you quick access to layer commands, including the ability to lock, rename, or add layers.

You can highlight any layer in this list then use the Up Arrow and Down Arrow keys to scroll through the CAM data in single-layer mode. The Right Arrow key will make all layers visible, while the Left Arrow key will isolate the highlighted layer. Multiple layers can be selected by using the standard Shift+Click and Ctrl+Click features, allowing you to show, hide, or delete various layers at once. You can use the + and * keys on the numeric keypad to cycle through all visible layers or only signal/plane layers, respectively.

Layers may be deleted from the panel, but doing so is an irreversible action. The Undo command in the Edit menu will not restore deleted layers.

You can toggle back and forth between the CAMtastic panel and the active CAM document by using the Shift+F5 keyboard shortcut. The F4 key will toggle the visibility state of all floating panels.