OrbbecSDK_ROS2/orbbec_camera/examples/gige_action_command

GigE Action Command

This example starts two Gemini 335Le cameras in Group Actions synchronization mode and one host-side Action Command sender. The sender is intentionally created once at the top level because a GVCP Action Command can trigger multiple cameras.

Requirements

• Gemini 335Le firmware 1.8.24 or later
• Orbbec SDK 2.10.2 or later
• Both cameras and the host on the same network

Before running the example, change the two net_device_ip values in multi_gige_action_command.launch.py to match the cameras.

Start the cameras and sender

ros2 launch orbbec_camera multi_gige_action_command.launch.py

The launch file creates these device-scoped configuration services and one network-scoped sender:

/camera_01/get_action_config
/camera_01/set_action_config
/camera_02/get_action_config
/camera_02/set_action_config
/gige_action_command_node/send_action_command

Configure the cameras

Configure Action Signal block 0 on both cameras with matching keys and masks:

ros2 service call /camera_01/set_action_config \
  orbbec_camera_msgs/srv/SetActionConfig \
  "{device_key: 1, selector: 0, group_key: 1, group_mask: 1}"

ros2 service call /camera_02/set_action_config \
  orbbec_camera_msgs/srv/SetActionConfig \
  "{device_key: 1, selector: 0, group_key: 1, group_mask: 1}"

Read the configuration back when needed:

ros2 service call /camera_01/get_action_config \
  orbbec_camera_msgs/srv/GetActionConfig \
  "{selector: 0}"

Trigger the group

The service exposes three trigger modes. Every camera whose device key, group key, and group mask match the request will be triggered.

Immediate trigger

Set trigger_mode to 0. The delay and scheduled time fields must be zero:

ros2 service call /gige_action_command_node/send_action_command \
  orbbec_camera_msgs/srv/SendActionCommand \
  "{device_key: 1, group_key: 1, group_mask: 1, broadcast_ip: '255.255.255.255', trigger_mode: 0, delay_ms: 0, scheduled_time: 0}"

Relative-delay trigger

Set trigger_mode to 1 and provide a positive delay in milliseconds. The node reads the host system clock, adds the delay, and converts the result to the absolute GVCP/PTP timestamp expected by the SDK. This example schedules the command one second in the future:

ros2 service call /gige_action_command_node/send_action_command \
  orbbec_camera_msgs/srv/SendActionCommand \
  "{device_key: 1, group_key: 1, group_mask: 1, broadcast_ip: '255.255.255.255', trigger_mode: 1, delay_ms: 1000, scheduled_time: 0}"

The host CLOCK_REALTIME must be synchronized to the same PTP domain as the cameras, for example by using phc2sys. The launch file enables camera PTP synchronization, but it does not configure the host PTP services. Choose a delay long enough for the command to reach the cameras before its target time.

Absolute PTP-time trigger

Set trigger_mode to 2, leave delay_ms at zero, and provide a future encoded PTP timestamp. The upper 32 bits contain seconds and the lower 32 bits contain nanoseconds:

ros2 service call /gige_action_command_node/send_action_command \
  orbbec_camera_msgs/srv/SendActionCommand \
  "{device_key: 1, group_key: 1, group_mask: 1, broadcast_ip: '255.255.255.255', trigger_mode: 2, delay_ms: 0, scheduled_time: <PTP_TIMESTAMP>}"

The response returns encoded_scheduled_time, the exact 64-bit value sent to the SDK. For delayed triggering this is the timestamp calculated by the node. success: true means the host dispatched the GVCP command; the protocol does not return a device acknowledgment.