What is in this article?:
- Hardware/Software Tool Documents Undocumented PCBs
- The Better Solution
- Learning Method
A documentation recreation tool product called RevEngfor REVerse ENGineering supports the increasingly vexing problem for users and maintainers of long life systems where support strategy for spares and repairs are critical issues. This includes water and electricity utilities, medical equipment, military systems, air traffic control, aircraft maintenance, avionics simulation, traffic control, trains, and signaling.
The Better Solution
The RevEng System creates professional quality circuit schematic diagrams from a sample PCB that has no documentation. The RevEng System consists of a PC-controlled continuity-detecting hardware system, SYSTEM8 Ultimate control software, and EdWin, a fully featured CAD package. RevEng ‘learns’ the connectivity of the sample circuit, producing a netlist of the components and connections for importing into EdWin software. The result is professional quality circuit diagrams and even new PCB layouts, if required.
RevEng’s learning process is achieved using a selection of clips, connectors, and probes that you attach to components on the board under test. SYSTEM8 Ultimate guides the operator to place and move the clips around the board. SYSTEM8 Ultimate generates an efficient sequence of clip combinations and movements that make it possible to learn all possible connections, but the operator can override the automatic placement of the clips, if necessary.
To minimize operator errors, the system applies an orientation check and pin check to confirm clip contact and position. RevEng completes its learning process without the need for applying power to the board and limits the applied voltage and current so that semiconductor gates are not affected - which also makes it safe to use on low power technologies. You can use the resulting netlist as an input to CAD packages and as data input for ATE programs.
SYSTEM8 Ultimate software controls the system hardware and provides links with the CAD software. Its key features include: Icon-driven operation, context-sensitive help, unlimited number of clips and connectors, partial circuit learn and draw, repeat learn and verify, optimized clip movement, digital or analog circuits, guided probe for non-standard components, suspend/restart/terminated at any stage, etc.
The EdWin professional drawing package enables the fast generation of drawings by importing the netlist and using an automated process to place components and signal routing. The resulting drawings can include bus structures and multi-page schematics. EdWin has capabilities that include features such as: importing the netlist to place components, auto routing signals, multi-page schematics, bus structure support, an extensive library of over 12,000 devices, ‘rubber band’ and ‘rats nest’ functions, block move and rotate, etc. The library includes discrete components, analog and digital ICs, microprocessors, memories, and connectors - but new and custom devices can be easily added without necessarily knowing the function of the device or even which pins are inputs or outputs. Fig. 2 is an actual example of a redrawn circuit diagram.
An enhanced version of the CAD software allows generation of artwork for a circuit board layout, design verification, and simulation. Optional capabilities include Bill of Materials, PCB Layout, Mix-mode simulation, Arizona Autorouter, Thermal Analyzer, EDSpice, EMC + Signal Integrity. Edwin’s special features enable same-day drawings of unknown, complex boards.