Modbus Master Node
Modbus enables communication among many devices connected to the same network, for example, a system that measures temperature and humidity and communicates the results to a computer. Modbus is often used to connect a supervisory computer with a remote terminal unit (RTU) in supervisory control and data acquisition (SCADA) systems. Many of the data types are named from its use in driving relays: a single-bit physical output is called a coil, and a single-bit physical input is called a discrete input or a contact. Modbus provide word data types for the number value are named register: a word value for read/write is called a holding register, and a word value for input is called a input register. Modbus-Master Node is a ROS node, it can be set to access data form Modbus server and provide ROS2 DDS topic for user to subscribe, user can quickly receive Modbus data and do the post data process, for example data parse/store/analysis etc. Below chapter will introduce you about how to use Modbus-Master Node.
Topic Definition
The topic of Modbus-Master are defined as below:
/adv/modbusmaster
Message Definition
The messages definition is defined in below link:
Configuration
To config Modbus settings, please refer the guide: Modbus Master Configuration Guide
Verify Sensor Data
The message is updated periodically, you can use ROS2 utility to verify the data update:
Step1. Setup ROS2 environmant variables:
$ source /opt/ros/${ROS_DISTRO}/setup.bash
Step2. Setup Node message:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/include/edge-converter-ros2/adv_msgs/install/local_setup.bash
Step3. List all topics:
$ ros2 topic list
output:
/adv/parameter_events
/adv/modbusmaster
/parameter_events
/rosout
Step4. Echo node data
$ ros2 topic echo /adv/modbusmaster
output:
---
sensor: Modbus-Master/Device/Sensor-Device-1/Sensor/Temperature
type: v
bv: false
v: 16.0
sv: ''
ts: 1677660801212
---
sensor: Modbus-Master/Device/Sensor-Device-1/Sensor/Door-Open
type: bv
bv: false
v: 0.0
sv: ''
ts: 1677660802511
---
sensor: Modbus-Master/Device/Sensor-Device-1/Sensor/FAN-Speed
type: v
bv: false
v: 2636.0
sv: ''
ts: 1677660803055
---
Run Sample Client
This session describe how to subscribe data using sample client.
Node.js
The program rclnodejs_edge_data_client is a node.js example for user to learning how to use rclnodejs client to subscribe node's data. Please follow below steps to run the program, when the program launched, it will subscribe node's data and print the data in the console screen.
Subscribe Sensor
Step1. Setup ROS2 environmant variables, replace ROS_DISTRO with your ROS2 distribution (foxy, humble) to run this command:
$ source /opt/ros/${ROS_DISTRO}/setup.bash
Step2. Setup OPCUAClient NodeS message:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/include/edge-converter-ros2/adv_msgs/install/local_setup.bash
Step3. Go to node.js sample path:
$ cd /usr/local/Advantech/ros/${ROS_DISTRO}/sample_code/edge-data-client/rclnodejs_edge_data_client/
Step4. Run node.js sample:
$ node example_SubscribeSensor.js "rclnodejs_ModbusMaster_subscriber" "/adv/modbusmaster"
Step5. Verify received data:
You have entered arguments:
node name: rclnodejs_ModbusMaster_subscriber
message topic: /adv/modbusmaster
----------------------------------------------
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Temperature", v = 21.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Door-Open", v = 1.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/FAN-Speed", v = 2814.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Humidity", v = 44.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Light-Switch", v = 0.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Set sensor
This session describe how to set data by set action. To run the set sensor sample, your device need have writable sensor supported.
Step1. Setup ROS2 environmant variables, replace ROS_DISTRO with your ROS2 distribution (foxy, humble) to run this command:
$ source /opt/ros/${ROS_DISTRO}/setup.bash
Step2. Setup OPCUAClient Node Message:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/include/edge-converter-ros2/adv_msgs/install/local_setup.bash
Step3. Go to node.js sample path:
$ cd /usr/local/Advantech/ros/${ROS_DISTRO}/sample_code/edge-data-client/rclnodejs_edge_data_client/
Step4. Run set sensor sample:
Command:
node example_SetSensor.js [node name] [action] [sensor] [type] [value]
Example:
$ node example_SetSensor.js "rclnodejs_ModbusMaster_setter" "adv_modbusmaster_set" "Modbus-Master/Device/Sensor-Device-1/Sensor/FAN-Speed" "v" 3000
Step5. Received data:
[INFO] [1671431728.320213435] [adv.rclnodejs_ModbusMaster_setter]: Waiting for action server...
[INFO] [1671431729.034446428] [adv.rclnodejs_ModbusMaster_setter]: Sending goal request...
[INFO] [1671431729.384845693] [adv.rclnodejs_ModbusMaster_setter]: Goal accepted
[INFO] [1671431729.774134098] [adv.rclnodejs_ModbusMaster_setter]: Goal suceeded with result: 202
Python
The program rclpy_edge_data_client is a Python client example for user to understand how to use rclpy to subscribe node's data. Please follow below steps to run the program, when the program launched, it will subscribe node's sensor and print the data in the console screen.
Subscribe Sensor
Step1. Setup ROS2 environmant variables, replace ROS_DISTRO with your ROS2 distribution (foxy, humble) to run this command:
$ source /opt/ros/${ROS_DISTRO}/setup.bash
Step2. Setup Node message:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/include/edge-converter-ros2/adv_msgs/install/local_setup.bash
Step3. Setup sample variables:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/sample_code/edge-data-client/install/local_setup.bash
Step4. Run Python sample:
$ ros2 run rclpy_edge_data_client listener "rclpy_ModbusMaster_subscriber" "/adv/modbusmaster"
Step5. Verify received data:
You have entered arguments:
node name: rclpy_ModbusMaster_subscriber
message topic: /adv/modbusmaster
----------------------------------------------
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Temperature", v = 21.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Door-Open", v = 1.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/FAN-Speed", v = 2814.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Humidity", v = 44.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Light-Switch", v = 0.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
C++
The program rclcpp_edge_data_client is a C++ example for user to understand how to use rclcpp to subscribe node's data. Please follow below steps to run the program, when the program launched, it will subscribe node's sensor and print the data in the console screen.
Subscribe Sensor
Step1. Setup ROS2 environmant variables, replace ROS_DISTRO with your ROS2 distribution (foxy, humble) to run this command:
$ source /opt/ros/${ROS_DISTRO}/setup.bash
Step2. Setup Node message:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/include/edge-converter-ros2/adv_msgs/install/local_setup.bash
Step3. Setup node variables:
$ source /usr/local/Advantech/ros/${ROS_DISTRO}/sample_code/edge-data-client/install/local_setup.bash
Step4. Run Python sample client:
$ ros2 run rclcpp_edge_data_client listener "rclcpp_ModbusMaster_subscriber" "/adv/modbusmaster"
Step5. Verify received data:
You have entered arguments:
node name: rclcpp_ModbusMaster_subscriber
message topic: /adv/modbusmaster
----------------------------------------------
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Temperature", v = 21.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Door-Open", v = 1.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/FAN-Speed", v = 2814.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Humidity", v = 44.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00
Data: sensor = "Modbus-Master/Device/Sensor-Device-1/Sensor/Light-Switch", v = 0.00
Data: sensor = "Modbus-Master/Link/Net1/Message", sv = "Link connected"
Data: sensor = "Modbus-Master/Link/Net1/Status", v = 1.00