Engineers choosing between Commercial-Off-The-Shelf (COTS) resolver simulators and custom FPGA solutions must evaluate maintenance, cost, and scalability. While FPGAs offer customization, COTS PXI resolver simulation modules provide faster integration, guaranteed accuracy, and long-term support for high-speed simulation.
Designing and validating automated test equipment (ATE) requires careful evaluation of every component. For test systems involving resolvers—rugged analog sensors essential for measuring angular position—the choice of simulation and interface hardware has significant implications for long-term performance and scalability. Engineers often face a critical decision: either develop a custom Field-Programmable Gate Array (FPGA)-based solution or integrate a COTS module such as Pickering’s Resolver Simulator.
This decision goes beyond simple cost analysis. It directly impacts project timelines, overall costs, and the reliability and scalability of the test system. This article explores common challenges engineers face when designing electronic test systems and compares the technical trade-offs of PXI resolver simulation with those of custom FPGA solutions.
The following three sections explore typical challenges in electronic test system design and how the choice between a COTS resolver simulator and a custom FPGA solution addresses them.
Challenge: Lisa, a test engineer, manages multiple ATE systems for a diverse product portfolio. One system uses a custom FPGA-based resolver simulation card developed in-house, but it has become a maintenance burden. Intermittent signal integrity issues require frequent troubleshooting by engineers with specialized VHDL (Very High-Speed Integrated Circuit Hardware Description Language) knowledge. In addition, firmware updates for new unit-under-test (UUT) profiles take significant time and carry the risk of regression errors, delaying production workflows.
Technical Deep-Dive: Lisa’s problem stems from the complexity of maintaining a custom FPGA-based solution, which requires expertise in several areas:
Long-term reliability depends on the quality of the original design and the availability of specialized engineers. Component obsolescence further complicates maintenance, as replacing a discontinued part could require an expensive redesign.
COTS Solution Architecture: Switching to a Pickering PXI/PXIe Resolver Simulator (model 41/43-670) addresses these challenges:
Challenge: Tom, a project manager for a growing electronics manufacturer, needs to deliver a new test system on a strict budget. While the bill of materials (BOM) for an FPGA-based solution appears lower than the cost of a COTS resolver simulator, Tom is concerned about hidden development and validation costs.
Technical Deep-Dive: Understanding cost-effectiveness requires analyzing the total cost of ownership (TCO), not just upfront expenses. Developing a custom FPGA solution involves significant non-recurring engineering (NRE) costs:
In total, developing a custom solution can take six to nine months of engineering effort. Factoring in loaded engineering salaries, the TCO for an FPGA solution often exceeds the initial cost of a COTS module.
COTS Solution Architecture: A Pickering Resolver Simulator eliminates these NRE costs:
Challenge: Alex, a systems architect, is designing an electronic test system that initially requires four resolver simulation channels but must scale to sixteen channels within two years.
Technical Deep-Dive: Scalability is a key consideration when designing test systems. With a custom FPGA-based solution, scaling can be difficult:
COTS Solution Architecture: The modular PXI/PXIe platform is designed for scalability:
Below is a cost and performance comparison between the Pickering 41/43–670 PXI LVDT/RVDT/High Speed Resolver Simulator, NI’s R-Series PXIe-7866 module, and custom FPGA-based solutions.
| Specs/Attributes | Pickering 41/43-670 PXI VDT/Resolver Simulator | NI R Series PXIe-7866 Module | Custom FPGA Solution |
| Primary purpose | Purpose-built simulation for LVDT / RVDT / Resolver sensors | General FPGA I/O + high-speed control for many applications | Fully tailored hardware + FPGA logic for a specific use case |
| Best fit | ATE / HIL sensor simulation, production test | High-performance test + control systems needing custom FPGA behavior | High-volume or ultra-special requirements where off-the-shelf doesn’t fit |
| Time to deploy | Fast (configured as an instrument) | Medium (requires LabVIEW FPGA + integration) | Slowest (architecture, PCB, FPGA dev, validation) |
| Engineering effort | Low | Medium to high | Very high |
| Integration effort | Low (instrument-style API) | Medium (FPGA + host code) | High (drivers, APIs, hardware integration) |
| I/O type relevance to LVDT/RVDT/Resolver | Directly designed for it | Not native — must be implemented | Can be perfect, but only after heavy development |
| Determinism / latency | High (instrument deterministic behavior) | Very high (FPGA deterministic) | Highest possible (if designed correctly) |
| Maximum performance headroom | High for sensor simulation needs | Very high (FPGA fabric, fast I/O) | Unlimited (bounded by budget/skill) |
| Flexibility (non-sensor use cases) | Low (specialized) | High | Highest |
| Scalability across test stations | High (repeatable instrument) | Medium (cost + FPGA maintenance) | Medium/High (depends on how well standardized) |
| Repeatability across units | High | High | Variable (depends on manufacturing + calibration approach) |
| Calibration / traceability | Straightforward | Possible, but depends on implementation | Fully custom (you must design traceability plan) |
| Cost (hardware) | Low–Medium (typically best $/channel for this job) | High (premium PXIe FPGA module) | Very high (NRE + hardware) |
| Cost (development / NRE) | Low | Medium–High | Very high |
| Cost (lifecycle support) | Low | Medium (FPGA code + NI stack upkeep) | High (you own everything forever) |
| Vendor lock-in | Low | Medium–High (NI toolchain ecosystem) | Medium (depends on FPGA vendor/toolchain) |
| Risk level | Low | Medium | Highest |
| Typical buying decision | “We need a resolver/LVDT simulator that works now.” | “We need FPGA performance + we’re okay building the functionality.” | “We must own the full stack or hit specs nobody sells.” |
For electronic test systems where reliability, accuracy, and scalability are critical, COTS resolver simulators like Pickering’s offer significant advantages:
While custom FPGA solutions may provide added flexibility for niche applications, for most resolver simulation needs in automated test systems, modular COTS solutions are the more reliable, scalable, and cost-effective choice.
A: Yes, modern PXI modules like the Pickering 41–670 and 43–670 support rotation speeds up to 130,000 RPM. This high-speed simulation capability is essential for testing advanced servo systems in electric vehicles and aerospace applications where precise control at high rotational velocities is critical.
A: Yes, these modules feature integrated relays on both input and output lines. This allows engineers to introduce specific fault conditions, such as open circuits or short circuits, directly into the signal path to verify how the Device Under Test (DUT) responds to sensor failures.
A: Yes, the 43–670 is a PXIe module compatible with PXIe and PXIe-Hybrid chassis slots, including those from National Instruments (NI). The 41–670 is a standard PXI module compatible with any PXI or PXIe-Hybrid chassis.
A: Our module simulates the electrical behavior of a resolver sensor, LVDT or RVDT. It accepts an excitation signal (input) and generates two output signals (sine and cosine) that, in the case of resolver simulation, represent the angular position of a rotating shaft. The 41–670/43–670 modules use on-board transformers to ensure galvanic isolation and precise signal generation. By adjusting the amplitude ratio of the sine and cosine outputs relative to the excitation, the module simulates specific rotation angles and speeds, allowing the test system to verify the performance of a resolver-to-digital converter or an ECU.
A: These modules can simulate rotation speeds up to 130,000 RPM (130kRPM). This high-speed capability is essential for testing advanced servo systems found in modern electric vehicles (EVs) and aerospace applications, where precise control at high rotational velocities is critical.
A: Pickering Interfaces offers a standard three-year warranty on all manufactured products, including the 41–670 and 43–670 modules. We guarantee long-term product support to ensure your test systems remain operational for years to come. Additionally, our global team of technical experts provides ongoing consultation and support to assist with system integration and troubleshooting.
A: All necessary documentation, including the detailed user manual, datasheet, and software drivers (VISA, IVI, Kernel), CAD models and specific configuration guides to assist with your system design, is available for download on our website. These resources can be accessed from the individual product pages, or you can download the software drivers directly here.