Reported NMT state is incorrect

[mrmitchadams]

Describe the bug
The reported NMT state is incorrect, at least from what I have observed while using the Proxy Driver

To Reproduce
Setup:

  executor_ = std::make_shared<rclcpp::executors::MultiThreadedExecutor>();
  device_container_ = std::make_shared<ros2_canopen::DeviceContainer>(executor_);
  executor_->add_node(device_container_);
  spin_thread_ = std::make_unique<std::thread>(&spin, this);
  device_container_->init(can_interface_name, master_config, bus_config);
  auto drivers = device_container_->get_registered_drivers();
  for (const auto& [driver_node_id, driver] : drivers)
  {
    auto proxy_driver = std::static_pointer_cast<ros2_canopen::ProxyDriver>(driver);
    proxy_drivers_[driver_node_id] = proxy_driver;
    auto nmt_state_cb = [this](canopen::NmtState nmt_state, uint8_t node_id) {
      std::cout << "NMT CB, State: " << static_cast<int>(nmt_state) << std::endl;
    };
   proxy_driver->register_nmt_state_cb(nmt_state_cb);
  }

I later start one of the drivers as follows:

proxy_drivers_.at(device_node_id)->start_node_nmt_command();

This results in:

• The NMT state of the driver, as observed via candump, transitioning to Operational
• The registered NMT state callback being called and printing out "NMT CB, state: 5"
• The following being logged: "Slave 0x3: Switched NMT state to START"
• An /nmt_state topic is published indicating a new NMT state of "START"

This is all as expected.

However, when I later run:

proxy_driver->reset_node_nmt_command();

• The NMT state of the driver, as observed via 'candump', transitions to Initializing, then to Pre-Operational, as expected
• The registered NMT state callback being called and printing out "NMT CB, state: 5"
• The following being logged: "Slave 0x3: Switched NMT state to START"
• An /nmt_state topic is published indicating a new NMT state of "START"

The same behavior is seen when triggering NMT commands via the /nmt_start_node and /nmt_reset_node ROS services.

Expected behavior
Calling reset_node_nmt_command() resets the drive to pre-operational mode, as expected. However, the feedback that is given through the NMT callback, the logs, and the ROS topic all indicate that the NMT state is switched to "START" (or Operational) rather than Pre-Operational.

Logs

[ros2_control_node-1] Reset NMT
[ros2_control_node-1] NMT CB, State: 5
[ros2_control_node-1] [INFO] [1738690767.237019553] [transport_base]: Slave 0x3: Switched NMT state to START
[ros2_control_node-1] Start NMT
[ros2_control_node-1] NMT CB, State: 5
[ros2_control_node-1] [INFO] [1738690772.048130197] [transport_base]: Slave 0x3: Switched NMT state to START
[ros2_control_node-1] Reset NMT
[ros2_control_node-1] NMT CB, State: 5
[ros2_control_node-1] [INFO] [1738690775.697599678] [transport_base]: Slave 0x3: Switched NMT state to START
[ros2_control_node-1] Start NMT
[ros2_control_node-1] NMT CB, State: 5
[ros2_control_node-1] [INFO] [1738690780.508815138] [transport_base]: Slave 0x3: Switched NMT state to START
[ros2_control_node-1] Reset NMT
[ros2_control_node-1] NMT CB, State: 5
[ros2_control_node-1] [INFO] [1738690784.157194190] [transport_base]: Slave 0x3: Switched NMT state to START

From candump:

  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  00
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  00
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  05
  can0  703   [1]  00
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F
  can0  703   [1]  7F

From ROS2 CLI:

# ros2 topic echo /drive/nmt_state 
data: START
---
data: START
---
data: START
---
data: START
---
data: START
---

Setup:

• Device: Dell Precision 7670
• OS: Ubuntu 22.04.5 LTS (Docker Container)
• ROS-Distro: Humble
• Branch/Commit: humble