Enhanced Electro-Mechanical Collaboration

The trouble that poor communications can cause.

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By Alex Grange and Linda Mazzitelli

Integrating electronics into its mechanical environment comes with a number of challenges that boil down to Collision and Connectivity (does the cabinet bang against that capacitor?) and Synchronization (is mechanical designing to the latest PCB design and vice versa?). The culprit to problems that arise usually is the result of poor communications.

Modern designs require skills that span multiple design disciplines. This requires close communication between electrical and mechanical engineers from each team. Many products result from collaboration among teams that work across multiple countries and continents — a major challenge when communicating between the different designers and engineers in an electromechanical system.

Even now, a lot of companies rely only on data transfers using the Intermediate Data Format (IDF) between electrical and mechanical systems. With IDF, it’s quite difficult to locate where a change may have been made, often resulting in the need for written documentation to ensure effective communication — more or less cancelling a lot of the advantages of a paperless documentation process. If the changes are not effectively communicated, the result can be re-spins, missing deadlines, or even product recalls.

With the introduction of the ProSTEP iViP Incremental Data Exchange (IDX) communication protocol, designers are now able to fully synchronize their data between both ECAD and MCAD and more effectively collaborate on critical design items between domains ensuring that the design intent is interpreted correctly. This allows designers to collaborate and identify issues much more easily throughout the design process, which in turns enables more robust designs that get out to market faster.

Defining a design flow is critical in enabling an efficient process. The time invested in this stage reduces redundant steps and ensures that correct data is exchanged and enforced throughout the project. In most electro-mechanical projects, critical design constraints are first defined by the mechanical engineer, including board outline, mounting hole locations, placement / routing keep-out areas, connector placement etc.

The design requirements and board elements are then exchanged with the ECAD designer to ensure that the correct information is used to start the project. This initial exchange would be the ‘Baseline’ file and is the same as if you were using IDF – as it will contain the entire assembly database from the mechanical domain. However, that is the only similarity between the two.

The new ProSTEP iViP schema now allows you to go beyond sending a single, static file to/from the each design team by allowing each domain to send incremental data i.e. only what changed, after the initial Baseline exchange. This facilitates a much more consistent and accurate flow of information back and forth between design disciplines as it also provides a report of the differences, a way to include notes about what changed directly in the IDX file itself, and the ability to graphically interrogate the updates on the PCB or mechanical assembly and ‘Accept’ or ‘Reject’ them. This fosters closer collaboration and enables early identification of critical issues during the design flow.

Collaboration Process Example

Here are the typical steps that would define the workflow between ECAD and MCAD design tools using the ProSTEP iViP Schema. Figure 1 illustrates the steps:

  1. The mechanical engineer creates a PCB inside an assembly that mounts to existing hardware. Mounting holes are created, Keepins/Keepouts are defined, and critical components are placed.
  2. A ‘Baseline’ IDX file is exported to the ECAD designer.
  3. The Baseline is accepted in the ECAD design, synchronizing the ECAD with the MCAD databases.
  4. The ECAD designer then sends back a ‘Response’ file to the MCAD engineer that the Baseline has been accepted.
  5. The board is modified in either the MCAD or ECAD tool suite and sent to the respective tool using a proposal (Incremental) collaboration file Typically at this stage, the PCB designer will begin placing critical components on the board or will finish the placement and will send back over to MCAD for review.
  6. The ECAD designer (or MCAD engineer) then reviews the updates and either Accepts or Rejects the proposal and sends a response file back to the originator Note: In the case of multiple change proposals in one IDX file, items can be accepted/rejected individually by the receiving domain.
  7. The second designer/engineer accepts the ‘Response’ file and the process continues.

NOTE: ‘Response’ files allow each side to verify that the IDX file was received and reviewed. It also re-syncs the collaboration state between the two domains.

Fig 1
Figure 1: Process flow for ECAD/MCAD collaboration using ProSTEP iViP.

This article presents a high level overview of the facilitation of ECAD/MCAD collaboration using the ProSTEP iViP Schema. For a very detailed explanation, download the complete white paper here.

Linda Mazzitelli is a senior technical account specialist at PTC.