Engineering systems don’t live in a single domain: A smartphone board generates heat. A stepper motor responds to electrical signals. A power converter depends on a software control loop. Simulating any one of these separately from the others tells only part of the story. That’s the core challenge FMI co-simulation was built to solve, and it’s now integrated into\u00a0HyperLynx Analog Mixed Signal Analysis (AMS)\u00a0and\u00a0PartQuest Explore. This blog highlights the integration of Functional Mockup Interface (FMI) co-simulation capabilities into Siemens’ HyperLynx AMS and PartQuest Explore simulation tools.<\/p>\n\n\n\n
The Functional Mockup Interface (FMI) is a free, tool-independent open standard that allows different simulation environments to exchange data and run as one unified system. Rather than forcing engineers to rebuild models in a single tool, or manually stitch together results from separate simulations, FMI enables specialized tools to couple seamlessly, each contributing its strengths to a shared, system-wide analysis.<\/p>\n\n\n\n
FMI provides a standardized API and a container format called Functional Mockup Unit or FMU, that packages models for import\/export between tools. Importing FMUs enables subsystems modeled in different platforms to interact within a unified simulation, substantially improving workflow efficiency and model accuracy. FMUs come in two flavors:<\/p>\n\n\n\n
The FMI standard is widely adopted, with FMI 2.0 being the industry\u2019s prevalent version as of 2025. Over 270 tools across disciplines support FMI, including Siemens\u2019 own HyperLynx AMS, PartQuest Explore, Simcenter products, and leading third-party offerings like Simulink and Mathematica. The tool-independence and \u201cblack-box\u201d nature of FMUs means that domain experts can collaborate without deep expertise in each other\u2019s tools or exposing intellectual property.<\/p>\n\n\n\n
HyperLynx AMS is a robust analog\/mixed-signal simulator, tightly integrated with PCB design tools and supporting a range of model formats (SPICE, VHDL-AMS, Verilog-A\/AMS, IBIS, etc.). HyperLynx AMS introduced FMI support in its 2510 release, enabling both FMU export and import. Its workflow allows for assigning simulation models directly within the design schematic, reducing errors and time. With the addition of FMI, HyperLynx AMS can now collaborate with hundreds of other FMI-compatible tools for comprehensive co-simulation.<\/p>\n\n\n\n
A compelling demonstration pairs HyperLynx AMS with Simcenter Amesim<\/a><\/strong> for electromechanical co-simulation. An electrical subsystem driving a stepper motor is modeled in HyperLynx AMS, while the connected mechanical system, lives in Amesim. By exporting a tool-coupling FMU from HyperLynx AMS and importing it into Amesim, both subsystems simulate together.<\/p>\n\n\n\n PartQuest Explore, Siemens’ free, browser-based simulation environment, has also gained FMI compatibility, extending co-simulation to the cloud. The paper showcases an example involves\u00a0Simcenter Flotherm<\/a><\/strong>, a CFD tool for electronics thermal management. A standalone FMU exported from Flotherm is imported into PartQuest Explore, where an electrical model simulates a smartphone’s real-world usage. The co-simulation captures how each chip’s power dissipation drives temperature changes across the board, with the RF chip cooling during offline gaming while the processor heats up. This kind of thermal-electrical co-simulation would be extraordinarily difficult to achieve without FMI. PartQuest Explore can also\u00a0export\u00a0tool-coupling FMUs to locally installed tools like Amesim, replicating the same electromechanical workflow demonstrated in HyperLynx AMS, with identical results.<\/p>\n\n\n\n For teams designing complex electromechanical, thermal, or control systems, this is a meaningful step toward truly integrated, first-time-right engineering.<\/p>\n\n\n\n