[Practical Tool] Assembly Variables in Proteus PCB Design

Assembly variables provide a simple way to manage multiple product configurations in a single schematic and PCB project by specifying the assembled or unassembled status of each component on each variable.

Sometimes there are multiple products on the market on one PCB. Budget versions may not come with certain parts (such as Bluetooth), or have different configurations (such as RAM). Assembly variables provide engineers with a structured way to manage them during the design process in a way that all output systems understand. For example, parts that are not installed in a variant should not be displayed in the 3D viewer, nor should they appear in the bill of materials or assembly drawing.

• Multiple product variants are supported across the entire software suite.
• Quickly create and edit variables in the Design Explorer module.
• Set the assembly state of a part or specify a replacement part in a variable.
• The Variable Comparison Report details all changes to the base design.

spare parts

In Proteus, alternate parts can be specified in different variables, but these parts must be pin-compatible with the original part. As with normal use, this works in the Design Explorer, where you can change the properties of each variable. For example, assume that different amounts of memory are required in different product configurations. Here, instead of editing the assembly status, we want to change the part value and also edit other attributes like stock code and cost.

Variable comparison

When there are multiple variables on a board, it can sometimes be difficult to keep track of all the information. Fortunately, the variant comparison report will tabulate all differences between each variant and the base design. Since all project design is done in base design, the user can be told how each variant differs from the generic schematic. The reports themselves are automatically generated from the Project Notes module and can be updated or refreshed at any time with the click of a mouse.

output

All output systems of Proteus follow the configuration of assembly variables. In terms of schematics, this means that the BOM module will include the current variables in the title block, unassembled parts will not be listed, and substitute parts will be applied correctly. In terms of layout, the 3D viewer will not include unassembled parts, nor will they be exported into STEP or IGES assemblies for MCAD. Likewise, Pick and Place files and assembly drawings will not include parts that are considered unassembled in the currently selected variant.

Example

Assembly variables have many different uses in project design. Here are a few examples:

Product configuration: This can be different features in different variants (e.g. no Bluetooth module) or more capacity (e.g. more RAM).

Test Variables: Set up different test configurations for the product (e.g. power supply test). Or you may want to test two prototypes using different (pin-compatible) parts to evaluate performance, noise, efficiency, etc.

Version Control: Use different pull-up/pull-down resistors on the MCU pins to tell the firmware the version of the PCB.

The copyright of this article belongs to British Labcenter Company. The original link is as follows:

https://www.labcenter.com/assemblyvariants/