Table of Contents
This article outlines the various controllers in the imperix ecosystem and explains how each is optimized for specific niches in the power electronics domain, ensuring that first-time users can select the appropriate controller correctly.
Products presentation
All imperix controllers are based on a DSP + FPGA architecture that is fully programmable by the user. This common architecture is the foundational layer for extensive hardware abstraction, which in turn authorizes excellent interoperability and compatibility across devices and generations.
From a software perspective, all controllers are identical in the sense that they can be programmed from the same Simulink/PLECS control model, with only a few parameter changes. They also support the same workflow and provide the same runtime monitoring and tuning capabilities via Cockpit. At the hardware level, however, the controllers may present rather different characteristics, notably linked to their I/O resources, each being specifically optimized for a particular use case.
Overall, imperix offers three distinct types of controllers, as shown below:
B-Box family
The B-Box family comprises controllers designed for laboratory applications, where performance and flexibility are the main priorities. B-Box controllers are designed to be plug-&-play with imperix power modules (example) but are also flexible enough to be easily used with custom power hardware.
The differences between B-Box controllers are summarized below. Further details on their analog input stages are given in PN105 (B-Box RCP3.0), PN106 (B-Box micro), and PN252 (B-Box 4). Differences regarding user-programmable safety thresholds are given in PN257.
B-Board PRO
The B-Board PRO is the control board present inside B-Box RCP and B-Box micro, but is also available as a standalone control board. Its typical applications include industrial use or research, where the controller needs to be embedded directly in the power converter itself. In such a case, the main benefit of using B-Board PRO resides in the way it facilitates the transition between the development phase and the production phase, thanks to immediate portability from the B-Box RCP 3.
More information on the B-Board PRO can be found on the related product page.
TPI 8032
The TPI 8032 is the only product in the imperix portfolio that combines the power and control stages into a single product. Standing for Three-Phase Inverter, the TPI 8032 is a fully programmable inverter optimized for maximum flexibility on the software side, but in experiments where the topology remains constant. Typical applications include grid-connected inverters and the emulation of DERs in lab-scale microgrid applications.
More information on the TPI 8032 can be found on the product page.
| B-Box controllers | B-Board PRO | TPI 8032 | |
|---|---|---|---|
| Application target | Modular power electronic systems | Integration inside converters or custom controllers | Easy-to-use programmable inverter |
| Plug-&-play with imperix modules and sensors | YES | NO | YES, but only sensors: 4x analog inputs (RJ45) |
| Processing | B-Box 4: 4×1.5GHz + 504K FPGA Gen. 3: 2×1.0GHz + 125K FPGA | 2×1.0GHz + 125K FPGA | 2×1.0GHz + 125K FPGA |
| Analog I/Os | RJ45 for analog inputs | On high-density connectors (bottom side) | 4x analog inputs on RJ45 |
| Digital I/Os | Optical fibers for PWM signals VHDCI connectors for other digital I/Os | On high-density connectors (bottom side) | 8x GPIO as 5/12V electrical signals. |
| Software environments | ACG SDK or CPP SDK Free FPGA programming | ACG SDK or CPP SDK Free FPGA programming | ACG SDK or CPP SDK Free FPGA programming |
| SW-independent protections | YES | NO | YES (not configurable) |
| Product datasheet | B-Box 4 B-Box RCP 3.0 B-Box micro 3.0 | B-Board PRO 3.0 | TPI8032 |
B-Box devices
Within the B-Box family, imperix controllers essentially share the same type of I/O interfaces, namely RJ45 connectors for analog inputs, and plastic optical fibers (POF) for PWM outputs. Cross-compatible digital I/Os are also available at the rear side of the devices in electrical form.
On the other hand, differences among units offer freedom of choice, notably regarding:
- I/O count and related performance. The bandwidth and sampling rate of analog inputs, as well as the PWM resolution of digital outputs, differ significantly across devices.
- Computing performance. The B-Box 4 embeds a significantly more powerful processing system.
- Oscilloscoping capabilities. The B-Box 4 supports the so-called oversampling technology.
- Networking options. The B-Boxes 4 and 3 can be stacked for high-performance I/O extension, unlike the B-Box micro.
This results in the following product positioning:
- B-Box 4: Flagship controller with the largest set of capabilities and highest performance. Commercialized since 2026.
- B-Box RCP 3: High-performance controller with full support for networked control and direct portability to B-Board PRO. Commercialized since 2019.
- B-Box micro: Cost-optimized, teaching-oriented system with limited I/Os. Networked control is not supported.
I/O specifications
| B-Box 4 | B-Box RCP | B-Box micro | |
|---|---|---|---|
| Analog inputs | 24x RJ45 ports – Resolution: 16-bit – Simult. Fs: 20Msps – Bandwidth: 2.7MHz – Impedance: 5kΩ1 – Auto-ID: YES – Pre-amp gain: 1x – LPF: digital (++ precision) – Oversampling: YES | 16x RJ45 ports – Resolution: 16-bit – Simult. Fs: 0.5Msps – Bandwidth: 0.41MHz – Impedance: 3kΩ/100Ω – Auto-ID: NO – Pre-amp gain: 1x,2x,4x,8x – LPF: analog – Oversampling: NO | 8x RJ45 ports – Resolution: 16-bit – Simult. Fs: 2Msps – Bandwidth: 1.3MHz – Impedance: 20kΩ – Auto-ID: NO – Pre-amp gain: 2x – LPF: NO – Oversampling: NO |
| PWM outputs | 48x fiber + VHDCI outputs – 24x optic./elec. + 24x elec. – 250ps resolution – Oversampling: YES | 32x fiber + VHDCI outputs – 16x optic./elec. + 16x elec. – 4ns resolution – Oversampling: NO | 8x fiber outputs – 8x optical only – 4ns resolution – Oversampling: NO |
| Analog outputs | 24x RJ45 ports – Resolution: 12-bit – Update rate: 500 ksps – Shared with inputs | 4x SMA ports – Resolution: 16-bit – Update rate: 50 kHz spaceholder | Unavailable spaceholder spaceholder spaceholder |
| GPO | 24x VHDCI outputs – Logic level: 3.3V/5V | 16x VHDCI outputs – Logic level: 3.3V/5V | 8x PCB header outputs – Logic level: 5V |
| GPI | 24x VHDCI inputs – Logic level: 3.3V/5V | 16x VHDCI inputs – Logic level: 3.3V/5V | 8x PCB header inputs – Logic level: 5V |
| USR | 36x VHDCI pins – Logic level: 3.3V | 36x VHDCI pins – Logic level: 3.3V | 36x VHDCI pins – Logic level: 3.3V |
| Product datasheet | B-Box 4 | B-Box RCP3.0 | B-Box micro3.0 |
1 Low-impedance adapter available for purchase
Computational capability
Computational capability differs only across generations. While Generation 3 controllers are powerful enough for most typical applications, with achievable maximum control frequencies in the range of 250 kHz in CPU, the B-Box 4 is considerably more powerful and capable to run 4x more complex code at a given control frequency.
| Generation 4 | Generation 3 | |
|---|---|---|
| SoC architecture | Zynq Ultrascale+ | Zynq 7000 |
| Processing system | – 4x 1.5GHz AMD Cortex A53 -3 – 8GB DDR4 | – 2x 1.0GHz AMD Cortex A9 -3 – 1GB DDR3 |
| FPGA | Kintex US+ 504K – 350K programmable logic cells | Kintex 7 125K – 62K programmable logic cells |
| Product datasheet | B-Box 4 | B-Box RCP 3.0 B-Box micro 3.0 |
Supported communication protocols
Each controller supports various communication protocols. The more research-oriented devices (B-Box 4 and B-Box RCP) support many more protocols than the teaching-oriented device (B-Box micro).
| B-Box 4 | B-Box RCP | B-Box micro | |
|---|---|---|---|
| Ethernet-based | 1x Ethernet port – UDP/IP – OPC-UA – Modbus TCP | 1x Ethernet port – UDP/IP – OPC-UA spaceholder | 1x Ethernet port – UDP/IP – OPC-UA spaceholder |
| High-performance | 4x QSFP+ 40Gbit/s – RealSync – Aurora – Custom protocol | 3x SFP+ 10Gbit/s – RealSync – Aurora – Custom protocol | Unavailable spaceholder spaceholder spaceholder |
| CANBUS | 2x CANBUS ports – CAN-FD – CAN-2.0B | 1x CANBUS ports – CAN 1.0 spaceholder | Unavailable spaceholder spaceholder |
| Serial communication | 2x serial ports – RS422/RS485 – BISS-C – SSI – EnDat 2.0 | Unavailable spaceholder spaceholder spaceholder spaceholder | Unavailable spaceholder spaceholder spaceholder spaceholder |
| Product datasheet | B-Box 4 | B-Box RCP 3.0 | B-Box micro 3.0 |
Software-independent protections
The software-independent protections available on most imperix controllers have slightly different characteristics, which are summarized in the table below. Further details are given in PN257.
| B-Box 4 | B-Box RCP | B-Box micro | |
|---|---|---|---|
| Implementation | Protected FPGA firmware | Hardware comparators | Protected FPGA firmware |
| Scaling | Identified sensor: true value Third-party sensor: ADC value | ADC value | ADC value |
| Response speed | Ultra: <800ns Fast: 1.6µs | Fast: 1.6µs | Fast: 1.5µs |
| Configuration | In Cockpit | with Front panel1 | in Cockpit |
| Product datasheet | B-Box 4 | B-Box RCP3.0 | B-Box micro 3.0 |
1 Saving/restoring the protection configuration requires a USB key on the B-Box RCP3.0, as it’s entirely independent of Cockpit.
Application-based selection guide
Every imperix controller can run most control algorithms with excellent closed-loop performance. However, even in the specific scope of the power electronics domain, applications can be tackled from various perspectives, and imperix’s controller portfolio aims to provide a solution optimized for each use case.
When to select a B-Box family controller
The primary reasons to go for a B-Box family controller are to maintain the plug-&-play compatibility with imperix power modules, and be able to change the controlled topology in a couple of minutes by simply rewiring the power stage and changing the I/O mapping. This type of flexibility is often required in research laboratory settings. The selection of the specific B-Box controller depends on user requirements:
Selecting the B-Box 4
The B-Box 4 is imperix’s flagship controller. Apart from offering the largest number of I/Os, it also offers access to oversampled ADC and PWM data, enabling their scoping directly in Cockpit. This makes it the first-choice controller for easily researching and debugging high-performance applications, down to the modulation, from one device. Examples where this would prove particularly useful include:
- Quick start guide PE bundle (PN171)
- Single-phase PV inverter (AN003)
- Onboard battery charger for electric vehicles (AN010)
Selecting the B-Box RCP
As the previous flagship of the imperix controller portfolio, the B-Box RCP is a perfectly capable device that can perform well in a wide variety of applications (examples shown below). Its only limitations are the comparatively lower performance of processing and peripherals, and the missing oversampling feature.
Selecting the B-box micro
The B-Box micro is as computationally capable as the B-Box RCP 3.0 but is more limited in I/Os (and cost!). This makes it the ideal controller for teaching various concepts in power electronics that do not require a large number of I/Os:
When to select the TPI8032
The TPI8032 is the preferred controller/converter for lab-scale microgrid and distributed generation modelling, as it combines the programmability of the B-Board PRO with an all-in-one integrated 2-level 3-phase inverter with grid connection filters included.
This makes it the perfect solution for when flexibility in topology is not required, but flexibility in the number of modelled DERs is. The inverter can be programmed in various ways, as can be seen below, and can also be paralleled if the total power output needs to be scaled up:
When to select the B-Board PRO
The B-Board PRO is specifically designed to be embedded onto a pre-implemented or custom-designed power stage. It optimizes for better packaging at the expense of the high-end front-ends of the B-Box family controllers. These front-ends are normally not required for such embedded applications because the analog chain is implemented on the custom converter itself.
The two examples below give two examples of the types of applications that the B-Board PRO is optimized for:
Related Articles
Analog front-end configuration on B-Box RCP 3.0
Analog I/O configuration on B-Box 4
Analog inputs configuration on B-Box Micro
Safety recommendations for working in the lab
