FIU Serial Driver

C/C++ driver for communicating with a Bloomy Controls Fault Insertion Units over RS-485.

Features

• Modern, native C++20 library
• Supports Windows and Linux
• Implements all commands and queries supported by the FIU
• Exceptionless error handling (see below)
• C wrapper (include/bci/fiu/CInterface.h) for use in C and other languages
• Easy inclusion in CMake projects

Note

Exceptions are not handled internally unless it is necessary to do so. Any exceptions thrown by this library are considered critical exceptional situations, such as a failure to allocate memory.

Example Usage (C++)

This example connects to an FIU, queries the firmware version, and then sets a single channel's state, followed by all channels at once.

#include <bci/fiu/FiuClient.h>

#include <format>
#include <iostream>

int main(void) {
  using ec = bci::fiu::ErrorCode;

  bci::fiu::FiuClient client;

  auto ret = client.Open("COM4");
  if (ret != ec::kSuccess) {
    std::cerr << "Failed to open serial port: " << bci::fiu::ErrorMessage(ret)
        << '\n';
    return 1;
  }

  ret = client.SetBoxID(0x02);
  if (ret != ec::kSuccess) {
    std::cerr << "Failed to set box ID: " << bci::fiu::ErrorMessage(ret)
        << '\n';
    return 1;
  }

  auto resp = client.GetFirmwareVersion();
  if (resp) {
    auto [major, minor] = *resp;
    std::cout << std::format("Firmware version: {:d}.{:d}\n", major, minor);
  } else {
    std::cerr << "Failed to get firmware version: "
        << bci::fiu::ErrorMessage(resp.error()) << '\n';
    return 1;
  }

  ret = client.SetChannelState(0, bci::fiu::ChannelState::kVoltageMeasurement);
  if (ret != ec::kSuccess) {
    std::cerr << "Failed to set channel states: "
        << bci::fiu::ErrorMessage(ret) << '\n';
    return 1;
  }

  ret = client.SetAllChannelStates(bci::fiu::ChannelState::kDisconnected);
  if (ret != ec::kSuccess) {
    std::cerr << "Failed to set all channel states: "
        << bci::fiu::ErrorMessage(ret) << '\n';
    return 1;
  }
}

Example Usage (C)

This example performs the same operations as the C++ example above using the C interface.

#include <bci/fiu/CInterface.h>

#include <stdio.h>

static void FormatErr(const char* msg, int ec) {
  fprintf(stderr, "%s: %s (%d)\n", msg, FiuClient_ErrorMessage(ec), ec);
}

int main(void) {
  int ret = 1;
  int ec;
  FiuClientHandle handle = NULL;
  FiuFirmwareVersion fw_version;

  ec = FiuClient_Init(&handle);
  if (ec < 0) {
    FormatErr("failed to initialize client", ec);
    goto cleanup;
  }

  ec = FiuClient_SetBoxID(handle, 0x02);
  if (ec < 0) {
    FormatErr("failed to set box ID", ec);
    goto cleanup;
  }

  ec = FiuClient_Open(handle, "COM4");
  if (ec < 0) {
    FormatErr("failed to open port", ec);
    goto cleanup;
  }

  ec = FiuClient_GetFirmwareVersion(handle, &fw_version);
  if (ec < 0) {
    FormatErr("failed to get firmware version", ec);
    goto cleanup;
  }

  printf("Firmware version: %u.%u\n", fw_version.major, fw_version.minor);

  ec = FiuClient_SetChannelState(handle, 0, FIU_CHAN_STATE_VMEAS);
  if (ec < 0) {
    FormatErr("failed to set channel state", ec);
    goto cleanup;
  }

  ec = FiuClient_SetAllChannelStates(handle, FIU_CHAN_STATE_DISCONNECTED);
  if (ec < 0) {
    FormatErr("failed to set all channel states", ec);
    goto cleanup;
  }

  ret = 0;

cleanup:
  FiuClient_Destroy(&handle);

  return ret;
}

Building

To build the driver as a shared library (.DLL or .so), first configure CMake, then execute the build system. This project can also be built with Visual Studio.

cmake -B build -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON
cmake --build build

Adding to a CMake Project

In your CMakeLists.txt, fetch and link with the driver:

FetchContent_Declare(fiu-cpp
  GIT_REPOSITORY https://github.com/BloomyControls/fiu-cpp.git
  GIT_TAG v1.0.0
  GIT_SHALLOW TRUE
)
FetchContent_MakeAvailable(fiu-cpp)

target_link_libraries(my_program PRIVATE bci::fiu)

If you have already installed the driver to a standard location on your system, you can use find_package instead:

find_package(fiu-cpp 1.0.0 REQUIRED)

target_link_libraries(my_program PRIVATE bci::fiu)

Tip

On Windows, the MSI installer will register the CMake package in the Windows registry, so the above example will build and link successfully. However, because the DLL is not located in the PATH environment variable, the DLL will fail to be found at runtime. To fix this, you can add a CMake command to copy the DLL to the build directory and you can add an install target to copy the DLL when installing your target.

Dependencies

This library does not have any runtime dependencies aside from the standard C/C++ runtime libraries on your system. However, it does have some build dependencies. If these are installed on your system, CMake will find and use them if your installed versions are compatible. Otherwise, it will automatically fetch and build them as part of the build. The build dependencies are:

• Boost v1.88.0

These are linked statically, regardless of the build configuration.

License

Copyright (c) 2026, Bloomy Controls, Inc. All rights reserved.

This software is distributed under the BSD-3-clause license. See the LICENSE file or https://opensource.org/license/BSD-3-Clause for details.