Getting Started MQTT

If you want to interface OAS with another MQTT Client please see the Getting Started MQTT Broker guide.

Configure an MQTT Driver

Tags can be defined to connect to MQTT devices and software brokers with the built in MQTT Driver Interface.  The following steps can be used to setup direct communications with a MQTT Broker.

Step 1

OASStart Configure OAS application from the program group Open Automation Software.

 

Step 2

Select Configure-License and verify that MQTT is one of the available Drivers in the lower left of the form.  If you do not see the MQTT driver available contact support@openautomationsoftware.com to update your license.

Enabled Drivers

Note: You will need to be running Open Automation Software Version 8.26 or greater to support MQTT communications.  You can download the latest version at www.openautomationsoftware.com/downloads/open-automation-software/

Step 3

Select Configure-Drivers.

Configure Drivers

Step 4

Select localhost or the remote service you wish to modify with the Select button to the right of the Network Node list.

Network Node

Note: Optionally select the Live Data Cloud node if you are hosting Allen Bradley data over the Internet with a standard Internet connection.

Step 5

Enter a meaningful Driver Interface Name that you will refer to this physical connection when defining Tags with MQTT Source.

Define the properties for the desired physical connection.

Note: You may need to Set Default Network Adapter for Driver Interfaces of the operating system.

Set the driver to MQTT. Enter the IP Address of the broker. The default port is 1883.

MQTT Driver Configuration

Enter the User Name and Password if required.

Keep Alive Time – Default is 60 Seconds.

Reconnect Time – Default 10 Seconds. If the connection to the broker is lost the Reconnect Time determines how long to wait before attempting to reconnect.

Optionally define a secondary failover MQTT Broker if the primary MQTT Broker fails with the property Enable Failover.

If both the primary and secondary broker are offline the Return to Online settings determines the retry frequency.

View Driver Interface Failover for more information and and video demonstrating communications failover.

Step 6

Select the Add button in the lower part of the form to add the Driver Interface as an available selection when defining Tags in the next step.

Add Driver

Note: If you need to define several Driver Interfaces you can use the CSV Export and CSV Import on the toolbar in the upper right together with Microsoft Excel.

Publish Selected Tags to MQTT Broker

There are 2 ways to publish data from OAS to a MQTT Broker.  Both require Tags to be setup first for the data sources you want to transfer.

Note: If you wish to receive data from a MQTT Broker just to Reading Data from MQTT Broker below.

View the following video for a complete demonstration of how to publish data to MQTT Brokers, Azure IoT, and AWS IoT Gateway.

Step 1

Enable Publish Selected Tags at the bottom of the Driver configuration.

Step 2

Select to publish data continuously at a specified interval, based on event, or at a specific time of day.

IoT Publish Type

If Event Driven browse for a local or remote OAS tag that will trigger the publish.  Select a Boolean tag that will change state from false to true, true to false, or both.  Or choose an Integer tag that trigger a publish anytime the value changes other than 0.

IoT Publish by Event

Step 3

Enable Publish Latest Value Only to send only the latest value of each tag when published or disable to send all value changes since the last time a publish occurred.

Enabled Include All Tags Each Publish to send at least the latest value of each tag when published or disable to only send the tags that have changed since the last publish.

Enable Publish All Tags As One Topic to publish all tag values as one topic or disable to send each tag as its own topic.

IoT Publish Options

See examples in Step 6 below for each selectable option.

Step 4

Specify the Publish Topic Id if choosing to Publish All Tags As One Topic.

Specify the Tag Id, Value Id, an optional Quality Id, and Timestamp Id for each tag value that is sent.

IoT Publish Ids

When including the Timestamp Id also specify the timestamp format, use Custom to specify your own date and time format.

Step 5

Specify local and remote OAS tag variables to include in each publish and specify the Id.  Value is the current value from the data source or you can select any of the over 600 tag variables of each tag to publish.

IoT Publish Tags

Optionally use CSV Export and CSV Import buttons to set up additional tags to publish using Microsoft Excel.

When selecting remote tags use Basic Networking syntax or Live Data Cloud syntax in the tag path.

Step 6

Select Apply Changes to begin publishing to AWS IoT Gateway.  Select Save to save the new driver configuration within the tag file.

Examples:

Examples of publishing every 2 seconds with each tag value changing every second:

IoT Publish Options

Topic: oas_tags
{
  “values”: [
    {
      “id”: “Ramp”,
      “value”: 39,
      “quality”: true,
      “timestamp”: “2022-03-21T08:55:39.000Z”
    },
    {
      “id”: “Sine”,
      “value”: 0.8090169943749475,
      “quality”: true,
      “timestamp”: “2022-03-21T08:55:39.000Z”
    },
    {
      “id”: “Random”,
      “value”: 10,
      “quality”: true,
      “timestamp”: “2022-03-21T08:55:39.000Z”
    }
  ]
}
 
IoT Publish All Value Chagnes
 
Topic: oas_tags
{
  “values”: [
    {
      “id”: “Ramp”,
      “value”: 16,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:36.000Z”
    },
    {
      “id”: “Sine”,
      “value”: 0.587785252292473,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:36.000Z”
    },
    {
      “id”: “Random”,
      “value”: 96,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:36.000Z”
    },
    {
      “id”: “Ramp”,
      “value”: 17,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:37.000Z”
    },
    {
      “id”: “Sine”,
      “value”: 0.6691306063588583,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:37.000Z”
    },
    {
      “id”: “Random”,
      “value”: 26,
      “quality”: true,
      “timestamp”: “2022-03-21T09:03:37.000Z”
    }
  ]
}
 
IoT Publish Tag Id Topics
 
Topic: Ramp
{
  “value”: 35,
  “quality”: true,
  “timestamp”: “2022-03-21T09:07:15.000Z”
}
Topic: Sine
{
  “value”: -1,
  “quality”: true,
  “timestamp”: “2022-03-21T09:07:15.000Z”
}
Topic: Random
{
  “value”: 83,
  “quality”: true,
  “timestamp”: “2022-03-21T09:07:15.000Z”
}
 

Use Data Route to Send Data to MQTT

Step 1

See Getting Started – Data Route to define a Target tag in any source tag.

Reading Data from MQTT Broker

Step 1

Select Configure-Tags.

Configure Tags

Select localhost or the remote service you wish to modify with the Select button to the right of the Network Node list.

Network Node

Note: Optionally select the Live Data Cloud node if you are hosting Allen Bradley data over the Internet with a standard Internet connection.

Step 2

Select to Add a Tag.

Note: You can also add organizational Groups as many levels deep as you prefer and add tags to groups.  To do this first add a Group to Tags Group at the root level, then right click on the Group in the right window to add additional Groups or Tags.

Add Group

Step 3

Change the Data Source Tag property to MQTT.

Data Source MQTT

Step 4

Select the correct Driver Interface from the Driver Interface pull down list.

Step 5

Enter the topic.

MQTT Topic

Step 6

Select the Quality of Service.

Step 7

Set the Topic Timeout – 0 = Topic will never timeout. Any number greater than 0 will cause the data to be Bad Data Quality if the broker does not publish within the time frame specified.

MQTT Topic Timeout

Step 8

Select to include Timestamp and or Data Quality to the topic.

This will publish to the specified topic above OAS/Items Sent/Timestamp  and or OAS/ItemsSent/Quality.

MQTT Settings

Configuring the Default Network Adapter

If the communications for the MQTT driver is not working at all you may need to set the default network adapter priority in the operating system.

Step 9

To setup automated data transfer of any OAS Tag to any MQTT Broker see Getting-Started – Data Route and set the Target Destination to MQTT.

Step 10

To define multiple tags use the CSV Export and CSV Import on the toolbar in the upper right together with Microsoft Excel.

Note: You can also programmatically define Tags using the free to use OASConfig .NET Standard assembly,  OPCSystems .NET Framework 4 assembly, or REST API.

Step 11

Select the Save button on the toolbar at the top.

Save Button

Step 12

Create a directory on the local C: drive with the name OASDemo.

Save the file DemoTags.tags in the directory C:\OASDemo.  Of course use the correct path for Linux.

Save Tags

Step 13

Under Configure – Options set the Default Tag Configuration File so when the computer restarts the tag file will automatically be loaded.

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