Yokogawa-BrigitteZacharia for Yokogawa Technologies Solutions India

Posted on Jun 8, 2021

Leveraging e-RT3 Plus capabilities using Node-RED

Introduction

e-RT3 Plus is a versatile device that supports a variety of programming methods and tools.

You can leverage the capabilities of e-RT3 Plus by using Node-RED to develop industrial-grade applications. This programming environment uses a browser-based editor and easy-to-assemble nodes to create logical flows. The Node-RED flow editor simplifies programming by using a visual coding process, thus allowing you to solely focus on the operation without getting into the details of the code.

In this article, we will demonstrate how to create a Node-RED flow for collecting, storing, and visualizing data using e-RT3 Plus. To create the flow, open source tools such as InfluxDB, Node-RED, and Grafana are used.

Node-RED is installed in e-RT3 Plus. InfluxDB and Grafana are installed on a server PC. Data sent to e-RT3 Plus is picked up by Node-RED. Node-RED then processes this data and writes it into InfluxDB. Grafana, which is connected to InfluxDB, processes the data and provides powerful data visualization features.

Workflow

The following figure shows the workflow for collecting and visualizing data by using InfluxDB and Grafana with Node-RED.

Prerequisites

You must have a working knowledge of e-RT3 Plus components and setup, as well as a basic awareness of the different I/O modules used in this example.

Before you start creating a Node-RED flow, the following requirements must be met:

Hardware wiring must be completed.
InfluxDB and Grafana must be installed on the server PC.
Node-RED and m3io nodes must be installed on e-RT3 Plus.
InfluxDB nodes must be installed on e-RT3 Plus.

Note: InfluxDB and Grafana can also be installed on the e-RT3 Plus device separately.

For more information on how to install InfluxDB and Grafana on the e-RT3 Plus device, refer to the Appendix.

Hardware wiring

We will be using three I/O modules of the e-RT3 Plus device for this example.

AD08 – This is a 16-bit or 12-bit analog to digital converter.
DA04 – This is a 16-bit digital to analog converter.
HA12 – This is a high-speed data acquisition module.

In this example, the AD08, DA04, and HA12 are configured as shown in the above diagram. Using this configuration, simulated data is generated for use.

Note: The configuration described above serves as an example of a basic setup. Based on this understanding, a user can configure a similar setup to generate simulated data.

Install InfluxDB and Grafana on the server PC

This section describes how to install InfluxDB and Grafana using Windows 10 as the server PC. You can also use any other system as the server PC.

For information on using other systems as server PCs, refer to Docker's product documentation.

For information on how to install InfluxDB and Grafana on the server PC without using Docker, refer to the InfluxDB and Grafana documentation.

Follow these steps to install InfluxDB and Grafana on your Windows 10 server PC by using Docker:

Install Docker Engine.
Install InfluxDB with Docker
Install Grafana with Docker

Install Docker Engine

For information on how to install Docker on your system, refer to the product documentation.

Install InfluxDB with Docker

Follow these steps to install InfluxDB with Docker:

Note: If you are using a proxy, refer to the steps described in Proxy settings for Docker and then continue.

Open Command Prompt on the server PC.
Run the following command to download the InfluxDB docker image from Docker hub.
```
docker pull influxdb:1.8-alpine
```
Run the following command to create and start the InfluxDB container.
```
docker run -d -p {INFLUXDB_PORT_NUMBER}:{INFLUXDB_PORT_NUMBER} -it --name {influxdb-container-name} influxdb:1.8-alpine
```
Note: Here, {influxdb-container-name} is the name specified for the InfluxDB container. The default port number is 8086.

Influx DB is installed.

You can use the following key commands to start and stop the InfluxDB container:

To start.

   docker start {influxdb-container-name}

To stop.

   docker stop {influxdb-container-name}

Install Grafana with Docker

Follow these steps to install Grafana with Docker:

Open Command Prompt on the server PC.
Run the following command to download the Grafana docker image from Docker hub.
```
docker pull grafana/grafana:latest
```
Run the following command to start Grafana.
```
docker run -d -p {PORT_NUMBER}:{PORT_NUMBER} -it --name {grafana-container-name} grafana/grafana:latest
```
Note: Here, {grafana-container-name} is the name specified for the Grafana container. The default {PORT_NUMBER} is 3000.
To open the created Grafana container, type the following URL in the address bar of your web browser.

http://localhost:{PORT_NUMBER}

Note: The default port number is 3000.

Grafana is installed.

You can use the following key commands to start and stop the Grafana container:

To start.

   docker start    {grafana-container-name}

To stop.

   docker stop {grafana-container-name}

Install Node-RED and m3io nodes

Follow these steps to install Node-RED and m3io nodes on the e-RT3 Plus device:

Note: If you are using a proxy, refer to the proxy settings described in Send telemetry data from e-RT3 Plus to Azure IoT hub.

Open an SSH terminal.
Run the following command to install Node.js.
```
curl -fsSL https://deb.nodesource.com/setup_14.x | sudo -E bash -
sudo apt-get install -y nodejs
```
Note: In this example, we will be using node version Node.js LTS(v14.x).
Upload the .tgz files provided by Yokogawa to any directory in the e-RT3 Plus device by using WinSCP.

Click here to download the .tgz files.

For more information about how to transfer files to e-RT3 Plus using WinSCP, refer to Using WinSCP to transfer files to e-RT3 Plus.
Run the following command in the terminal to navigate to the folder where the .tgz files are copied.
```
cd {TGZ_FOLDER_PATH}
```
Here, TGZ_FOLDER_PATH, is the folder location of the .tgz files.
To complete the Node.js setup, perform these steps:
1. Run the following command to locate the global node_module folder.
```
npm list -g | head -1
```
  The default path of the node_module folder is /usr/lib.
2. Edit the /etc/environment file to add the following line.
```
NODE_PATH="{node_module_directory}/node_modules:"
```
  Here, {node_module_directory} is the path of the node_module folder obtained from the previous step.
3. The environment must be reloaded to reflect the changes to the environment variables. Run the following command to reload the environment:
```
source /etc/environment
```
Run the following command to install Node-RED and m3io globally.
```
sudo npm install -g --unsafe-perm node-red@1.2.9 m3io_nodejs-1.0.0.tgz
```
Note: If you are using a proxy, refer to the proxy settings described in the Appendix.

Note: To use the latest version of Node-RED, refer to the changelog and adapt any changes while performing the steps accordingly.
Run the following command to update the m3io settings in Node-RED.
```
sudo tar -xf node_red_settings.tgz --directory /
```
The /node_red folder is created in the root directory.
Run the following command to add the m3io nodes.
```
sudo tar -xf m3io_nodered-1.0.0.tgz --directory /node_red
```
The m3io_node folder is created in the node_red directory.

After installing the m3io nodes, run the following commands to start Node-RED.

sudo systemctl enable node-red.service
sudo systemctl start node-red.service

Once Node-RED is started, open a web browser of your choice, and type the following URL in the address bar to open the Node-RED editor.

http://{IP_ADDRESS_OF_ERT3}:{PORT_NUMBER}

Here, {PORT_NUMBER} is the configured port number for communication with e-RT3 Plus. The default port number is 1880.

{IP_ADDRESS_OF_ERT3} can be determined by running the following command in the terminal.
```
hostname -I
```
The Login page of the Node-RED editor window appears.

Note: If any error occurs, install the node-red-dashboard and try again.
Specify the login credentials.

By default the username is admin, and password is ert3_admin.

Note: To modify the default login configuration, refer to the official documentation.
Click Login.

The Node-RED editor page appears.

Install InfluxDB nodes

Follow these steps to install InfluxDB nodes:

Open the Node-RED editor.
In the upper-right corner, select Menu > Manage palette.
In the dialog box that appears, on the left pane, click the Palette tab, and then click the Install tab.
In the Search box, type node-red-contrib-influxdb.

The search results appear.
Click Install to install the InfluxDB nodes.

InfluxDB nodes are installed.

Getting Started

After we have set up the system and met the requirements, we can start configuring the system to collect data and display it on Grafana. This can be achieved by completing the following steps:

Create a database in InfluxDB
Create a Node-RED flow
Connect Grafana to InfluxDB
Configure Grafana to display the data

Create InfluxDB database

Follow these steps to create the InfluxDB database:

Open command prompt on the server PC.
Run the following command to start the InfluxDB container.
```
docker exec -it {influxdb-container-name} sh
```
Here {influxdb-container-name} is the name given to the created InfluxDB container.

Note: Type exit to exit the container.
Run the following command to connect automatically to the InfluxDB instance.
```
influx
```
Run the following command to create a database.
```
CREATE DATABASE <db-name>
```
Here, db-name is the name of the database that you want to create.

Create Node-RED flow

At this point, your system components have been installed, your database is running, and you have access to the Node-RED editor. Now, we will demonstrate the use of the Node-RED editor to create a simple flow that captures input data from the AD08 module and writes it into the InfluxDB database.

By using Node-RED’s characteristically intuitive and easy programming interface along with e-RT3 Plus, you can quickly develop flows to suit your requirements. Yokogawa has developed custom m3io nodes to be used in the Node-RED flows. These can be used in very much the same way as the standard Node-RED widgets. For this example, we will be using the readM3IoRegister custom node.

Follow these steps to create a simple Node-RED flow that reads data and writes it to the database:

Open the Node-RED editor.
On the left pane, select the inject node and drag it onto the workspace. This node will inject the data at a specified time interval.
Double-click the created node and configure the properties to read data every five seconds.
In the upper-right corner of the Properties page, click Done.
On the left pane, select the readM3IoRegister node and drag it onto the workspace. This node will read data from the AD08 registers.
Double-click the created node and configure its properties as necessary.

Note: In this example, according to our hardware configuration, the data is read from the register positions 2 and 3 in the AD08 module, which is located in slot 4. Therefore, Slot and Position is specified as 4 and 2 respectively. However, you must verify the slot location and positions from the Web Maintenance Tool before specifying the values.

To learn how to connect to the Web Maintenance Tool, refer to Remote Communication with e-RT3 Plus.
Create another readM3IoRegister in the same way, but this time, specify the position as 3.

Note: Again, the position must be verified from the Web Maintenance Tool and specified accordingly.
Now that we have read the data, we must create a node to write this data into the database. On the left pane, select the influxdb out node and drag it onto the workspace.
Double-click the created node and configure its properties as necessary.

Note: The database name must match the name specified while creating the InfluxDB database, the time precision must be in seconds, and the server URL must be http://{SERVER_PC_IP_ADDRESS}:{PORT_NUMBER}. Here, {SERVER_PC_IP_ADDRESS} is the IP address of the server PC, and {PORT_NUMBER} is the configured port. The default port number is 8086.
On the left pane, select the debug node and drag it onto the workspace. This node will verify the values that are being received. Edit the properties of the node as necessary.
Use connectors to connect all the nodes. The following figure shows the final flow to be created.
On the menu bar, click Deploy to activate the flow.
To start the flow, click the Inject button. This will start injecting the data into the flow.
In the upper-right corner of the Node-RED editor window, click the Debug tab.

The debug pane appears, displaying the values being read every five seconds.

Connect Grafana to InfluxDB

Now that we have data being written into the database, we can link InfluxDB and Grafana. This will allow Grafana to access the data written in InfluxDB. Grafana uses this data and provides you with a powerful interface to visualize this data.

Follow these steps to connect Grafana to InfluxDB:

To open Grafana, type the following URL in the address bar of your web browser.

http:// {IP_ADDRESS_OF_SERVER}:{PORT_NUMBER}

Note: The default port number is 3000.
On the login page, enter the login credentials.

Note: For both username and password, the default value is "admin".
Click Log In.
In the upper-left corner, click the Grafana icon to open the side menu.
From the side menu, click the Settings icon, and select Configuration > Data Sources.
On the page that appears, click Add data source.
From the list that appears, select InfluxDB.

The Settings page appears.

Alternatively, you can use the Search box to locate InfluxDB.
On the Settings page, specify the necessary details.

The following table describes the values to be specified in the corresponding fields on the Settings page.

Name : Provide a suitable name for the data source.

URL : http://{IP_ADDRESS_OF_SERVER}:{PORT_NUMBER}

Database : The database name specified while creating the InfluxDB database.
Click Save + Test.

For more information about using InfluxDB in Grafana, refer to the product documentation.

Configure Grafana to display the data

Once Grafana is connected to InfluxDB, we can move forward with displaying the data written in InfluxDB.
Follow these steps to visualize InfluxDB data on Grafana:

In the Grafana window, on the left pane, click the + icon and select Dashboard.
Click Add new panel.
In the lower-left corner, click the Query tab.
In the form that appears, select the parameter to be visualized.

You can also customize the appearance by using controls that are available on the right pane.
In the upper-right corner, click Save and then click Apply.

The data from the InfluxDB appears according to the configured visualization settings.

You can also add additional panes as well as measurements that can be displayed simultaneously.
Additionally, Grafana can be configured to display the data in real time.

For more information about using Grafana, refer to the product documentation.

Conclusion

As demonstrated in this article, it is easy to store and visualize the simulated data by configuring a flow using Node-RED’s graphical interface and deploying it on e-RT3 Plus. This opens up infinite opportunities to process, analyze, and visualize data with minimal time and effort.

Appendix

It is possible to collect and visualize data by installing InfluxDB and Grafana on the e-RT3 Plus device. In some cases, users will find it more convenient to use this type of system configuration.

This section describes the procedure to install InfluxDB and Grafana on the e-RT3 Plus device.

Install InfluxDB on e-RT3 Plus

Follow these steps to install and start InfluxDB:

Open an SSH terminal to communicate with the e-RT3 Plus device.

Note: To learn how to open an SSH terminal and communicate with e-RT3 Plus, refer to Remote Communication with e-RT3 Plus.

Run the following commands to add the InfluxData repository.

curl -s https://repos.influxdata.com/influxdb.key | sudo apt-key add -
source /etc/lsb-release
echo "deb https://repos.influxdata.com/${DISTRIB_ID,,} ${DISTRIB_CODENAME} stable" | sudo tee /etc/apt/sources.list.d/influxdb.list

Run the following commands to install and start InfluxDB service.
```
sudo apt update && sudo apt install influxdb
sudo service influxdb start
```
Note: For more information about enabling sudo privileges, refer to Send telemetry data from e-RT3 Plus to Azure IoT hub.

For more information about installing InfluxDB, refer to the product documentation.

Note: If you are using a proxy, refer to the proxy settings described in Proxy settings.

Install Grafana on e-RT3 Plus

Follow these steps to install and configure Grafana:

Open an SSH terminal.

To install Grafana, perform the following steps:

Run the following commands to install the required packages.

sudo apt install -y apt-transport-https
sudo apt install -y software-properties-common wget
wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -

Run the following command to add the repository for stable releases.

echo "deb https://packages.grafana.com/oss/deb stable main" | sudo tee -a /etc/apt/sources.list.d/grafana.list

Run the following commands to install Grafana.

sudo apt update
sudo apt install grafana

Finally, run the following commands to start the service and verify that the service has started.
```
sudo service grafana-server start
sudo service grafana-server status
```

For more information about installing Grafana, refer to the product documentation.

Proxy settings for Docker

Follow these steps to set the proxy settings for Docker in Windows:

Open a Command Prompt terminal to the server.
Navigate to the following path:

C:\Users\username\.docker

Edit the config.json file by following the steps in Configure the Docker Client.

If the config.json file does not exist, you must create it.

If the config.json file exists, ensure that its contents follow this format:

{
    "HttpHeaders":
    {
        "User-Agent":"Docker-Client/19.03.13 (windows)"
    },
    "auths":
    {
        "<registry name 1>.azurecr.io":{},
        "https://index.docker.io/v1/":{},
        "<registry name 2>.azurecr.io":{}
    },
    "credStore":"desktop",
    "credsStore":"desktop",
    "proxies":
    {
        "default":     
        {
            "httpProxy":"http://username:password@example.com:port/",
            "httpsProxy":"http://username:password@example.com:port/"
        }
    },
    "stackOrchestrator":"swarm"
}

This is an example of httpProxy and httpsProxy settings. Edit the details based on your environment as necessary.

Now, you must configure the Docker Desktop settings with the Proxy details.

To configure the Docker Desktop settings, perform these steps:
1. From the Start menu, open Docker Desktop.
  
  The Docker Desktop window appears.
2. In the upper-left corner, click the Settings icon.
  
  The Settings page appears.
3. Click on the Resources tab, and then click PROXIES.
4. Enable the Manual proxy configuration toggle key.
5. In the Web Server (HTTP) box, specify the following proxy URL:
  
  http://{username}:{password}@{proxy-server-url}:{port}
6. In the Secure Web Server (HTTPS) box, specify the following secure proxy URL:
  
  http://{username}:{password}@{proxy-server-url}:{port}
7. Click Apply & Restart to apply the settings and restart Docker Desktop.

The proxy settings are configured.

Proxy settings for npm

If you are using a proxy, run the following commands to configure the proxy settings for npm:

sudo npm -g config set proxy http://{username}:{password}@{proxy-server-url}:{port}
sudo npm -g config set https-proxy https://{username}:{password}@{proxy-server-url}:{port}

Here, username and password are the credentials of the server PC, proxy-server-url is the IP address of the server PC, and port is the port number of the server PC.