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Using NodeRED

Note

Your computer used in this step MUST be on the same network

Connecting to the dashboard

  1. Enter IP obtained from the previous step into a web browser (Google Chrome preffered) in the following format: YOURIP:1880
    Example: 192.168.2.61:1880
  2. The NodeRED dashboard should appear, with the Culnet OS tab and nodes on the nodes list

Loading the template nodes

  1. Locate the menu icon on the top right corner of the dashboard
  2. Click on Import, then Examples
  3. Locate the node-red-culnetv2 dropdown in the Examples tab
  4. Select readdo and click Import
  5. Click and place nodes on the flow
  6. Your flow should look something like this

Configuring the nodes

The first node: standardconf

This node will be the trigger node, starting the flow. Contents of this node are not used as of this moment.

The second node: modbus

This node will talk to the DO sensor via a serial port. Once it's done reading, the data is sent on msg.payload to the next node.

  1. Click on the Modbus node to reveal the configuration panel
  2. Enter fields as shown below and click Done
Name Value
Port /dev/ttyUSB0
Device ID 1
Baud Rate 19200
Register 2089
Read Length 10
Stop Bits 2
Parity none

Note the reading register is set to 2089; to read from 2090
More information on the Modbus protocol for Hamilton DO Arc sensors are available here.

The third node: hamilton

This node will decode data given from the modbus node and return a float value stored in a object in msg.sensors

  1. Click on the Hamilton node to reveal the configuration panel
  2. Enter a sensor name, select DO for sensor input type, and click on Done

The fourth node: debug

This node is part of NodeRED, for displaying msg from upstream nodes.

  1. Click on the debug node to reveal the configuration panel
  2. Make sure Output is set to complete msg object and in To, Debug Window is checked. Click on Done

Save the flow

Once you configure all nodes, it's time to save the flow. Click on Deploy located on the top right corner.

Running the flow

Once you've done configuring the flow it's time to run it.

Opening the Debug panel

Before running you will need to open the Debug panel to see the outputs.
Locate the bug icon on the menu on the top right corner

Starting the flow

Click on the button on the standardconf node

Checking the results

On the debug panel, a new message should appear. Expand the sensors and sensor name object to reveal the results.

If it looks something like this, congratulations! You successfully ran your first flow 🎉