Hi,

Here's a steps by steps:

Installing an MQTT broker

    
     The MQTT ThingWorx extension acts as an MQTT client, so in order to test it we need to install a local broker.
     One such open-source broker can be downloaded from http://mosquitto.org/download/

    Download the binary Windows installation: mosquitto-X.Y.Z-install-win32.exe from the download page and install it locally.

     Mosquitto depends on PThreads and OpenSSL, but does not redistribute them, so you need to download them following the instructions      in the readme-windows.txt included in the package.

     Please note that the Mosquitto build is 32-bit, so you must download 32-bit versions of both PThreads and OpenSSL DLL’s.

     After downloading and installing those two dependencies, you’ll maybe notice the famous DLL hell come true: your Windows system is      already spammed with all sorts of OpenSSL libraries, dropped in the PATH by various applications that you might have been installed in      the past: some of them are 32-bit, some 64-bit. Since we want to be sure that we use a 32-bit version (and probably the one we have just      downloaded), you have to adjust the PATH as seen by Mosquitto, remove all directories from the path that have nothing to share with      mosquitto, and add the new one. While you might think you can copy the new DLL’s to the Mosquitto folder, you’ll soon realize that      adjusting the PATH is a much better and resilient option.

     This is the PATH that I’ve set in the Command Prompt before running Mosquitto:

     Set PATH=C:\Windows\system32;C:\Windows;D:\opt\OpenSSL-Win32;D:\opt\OpenSSL-Win32\bin;D:\opt\pthreads-w32-2-9-1-release\Pre-built.2\dll\x86

Testing Mosquitto

     Before configuring the MQTT extension, test your local Mosquitto instance, as follows.
     Open three command prompts and set the PATH in them according to the previous section:

     - Command Prompt for the broker:

o   Run mosquitto –v to start the broker in verbose mode

     - Command Prompt for the client that subscribes to a topic

o   Run mosquitto_sub -v -i subclient-q 2 -t random/temp to start the subscriber client in verbose mode, using the subclient ID, quality of service 2, and topic random/temp

o   You will see that the broker logs a subscription request in its standard output

     - Command Prompt for the client that publishes a message to a topic

o   Run mosquitto_pub -q 2 -t random/temp -m 33 to start the publisher client with quality of service 2, topic random/temp, and message 33

o   You will see that the broker logs a publish request in its standard output, as well as the subscriber client

Testing the MQTT extension in Thingworx

• Download the MQTT extension from the PTC marketplace
• Import the saved zip file from the Import/Export menu tab (Import/Export > Extension > Import) in the Thingworx composer.
• Create a new thing and choose the MQTT template when asking for Thing Template in the General Information page

• Create the different properties related to the topic you wish to use (publish and subscribe) on the Properties page (e.g. temperature).
  
  
  
  
• To record the value history of a property checks the Logged box and add/create the value stream name in the General information page.
• Auto mapping Settings on the Configuration page controls whether you want Thingworx to automatically generate topic name(s) based on a pattern that can include server name {s}, thing name {t} and property name {p} token(s)
  

• Property to MQTT topic mapping paragraph allow you to map the topic (e.g. temp/random) with the property name (e.g. temperature) and publish and/or subscribe check box.
  
  
  
• Connection Settings requires, at least, the serverName (e.g. test.mosquitto.org), the serverPort (e.g. 1883) and a qos (Quality of Service) value from 0 to 2:
  • 0: The broker/client will deliver the message once, with no confirmation.
  • 1: The broker/client will deliver the message at least once, with confirmation required.
  • 2: The broker/client will deliver the message exactly once by using a four step handshake.

• Save your thing and test the connection by checking the isConnected service (value = true) on the Properties page - MQTT (ThingTemplate) - Properties paragraph
  
  
  (Note : I installed the Mosquitto client, subscribe to the topic and publish a message with value = 20)
  
  
• Once validated create a new mashup:
  • mashup type = Page and Layout Options = Static
  • add three widget: a gauge, a LED Display and a Time Series Chart
  • add an Entity by clicking on the Green Plus button on the upper right corner of the Entity area and choose the previously created thing.
  • add the GetProperties service, check the Mashup Loaded box, add the QueryPropertyHistory without checking the Mashup Loaded box and click Done button.
  • expand the GetProperties service and drag and drop your property (e.g. temperature) to both gauge and LED Display widgets (Select Binding Target = data)
  • expand the QueryPropertyHistory service and drag and drop the All Data parameter to the Time Series Chart widget (Select Binding Target = data)
  • save the mashup, give it a name and click on the View Mashup button.

Here’s the result:

If you want to get more information about the Mosquitto client please check the following website:
http://mosquitto.org/

To test the extension without installing a MQTT broker please check the following website:
http://test.mosquitto.org/

I hope this information helps you.
Please let me knowif you have question or need more information about this topic.
Regards,

Franck Bailleux

Hi,

I am trying to set one sample thing with mqtt,

It connects to mosquitto and also subscribes to the topic, but I always get "Socket error on client" when mosquitto is trying to push the message to Thingworx mqtt thing.

I am using thingworx 6.5.0 on tomcat 7.

This mosquitto server works well with eclipse paho based application on the same tomcat.

Any pointers would really of a great help.

Many Thanks

Amit

Hi Graham,

AMQP is a different protocol than MQTT.... the log message doesn't mention anything about MQTT or related ports.

You should verify your client configuration, addresses, ports, as well as the server side that it is allowing MQTT connections.

To verify the MQTT connection, try using the HiveMQ online MQTT web-client posted above in order to be sure that your broker is visible and working on the Internet.

Cheers,

Greg

Hi,

1 - Could you check if the MQTT extension has been correctly installed.
Go to Monitor (from the composer) and choose extension item and search for MQTT extension
If something goes wrong during MQTT installation you 'll be able to find some information.

2 - What is your operating system ? and the MQTT extension release ?