MQTT-flex

There is a lot of approaches in integration of MQTT in devices and systems. One vendor prefer one topic with structured data payload, the another one prefer tree topic structure with simple value in data payload. MQTT-flex is a standard MQTT with specific configuration approach. The goal of MQTT-flex is to give a user opportunity to integrate NETIO device with any system with different data approach.

Configuration of MQTT in devices supporting MQTT flex is done by JSON (JavaScript Object Notation). With MQTT-flex you can easily define the MQTT topics, payloads and device behaviour via text configuration in JSON object format. Since there is then lot of possibilities with such freestyle flexibility allowed, you can find bellow full set of all implemented attributes.

Supported devices:
PowerCable MQTT, PowerCable OEM (DevKit), PowerPDU 4PS, PowerDIN 4PZ, PowerBox 3Px

Simple MQTT-flex configuration example

{
     "config":{
        "broker":{
            "url":"broker.hivemq.com",
            "protocol":"mqtt",
            "port":1883,
            "ssl":false,
            "type":"generic",
            "username":"freedom",
            "password":"peace|LOVE|empathy4ALL"
        },
        "subscribe":[{
               "topic":"netio/${DEVICE_NAME}/output/1/action",
               "qos":0,
               "target":"OUTPUTS/1/ACTION",
               "action":"${payload}"
           }
       ],
       "publish":[{
               "topic":"netio/${DEVICE_NAME}/output/1/state",
               "qos":0,
               "retain":true,
               "payload":"${OUTPUTS/1/STATE}",
               "events":[
                   {
                       "type":"timer",
                       "period":"1000"
                   }
               ]
           }
       ]
   }
}

Client Configuration (broker section)

Put here MQTT client connection setup

This configuration example set NETIO device to connect to broker.hivemq.com with mqtt protocol, no ssl connection with credetials freedom/peace|love|empathy4ALL.

Device Control (subscribe section)

Put here array of topics where to subscribe

Device output 1 is controlled with action received by subscription to netio/${DEVICE_NAME}/output/1/action topic with QOS 0

Output State monitoring (publish section)

Put here array of topics where to publish.

Device send every 1000 ms message to topic with QOS 0, retain true information with output 1 state

Config sections

Broker

here you have to define URL or IP address of machine hosting MQTT broker, level of security used for protocol, auth data and optionally some specific MQTT attributes, which are in the spec, but not mandatory required

Attributes table overview

Item	Presence	Possible Values	Description	JSON Config Usage
url	mandatory		MQTT broker URL	"url":"broker.hivemq.com"
port	mandatory	1 - 65535	MQTT broker port	"port":1883
ssl	mandatory	true, false	Use SSL crypted communication selector	"ssl":false
type	mandatory	generic	Communication/setup type option	"type":"generic"
username	mandatory	regexp+len	Credentials for MQTT broker	"username":"freedom"
password	mandatory	regexp+len	Credentials for MQTT broker	"password":"peace|LOVE|empathy4ALL"
clientid	optional	regexp+len	MQTT clientid. Max. 32 characters. Variables ${DEVICE_MAC} or ${DEVICE_NAME} can be used	"clientid":"myEcoTable01"
keepalive	optional	1 - 65535	MQTT keep alive period in seconds	"keepalive":90

Subscribe

Hints to usage

When receive message in topic do action on target.

actiondef: When message in topic match actiondef payload do action on target.

Attributes table overview

Item	Presence	Possible Values	Description	JSON Config Usage
topic	mandatory	see table below	specification of the topic, which MQTT-flex device listens from broker and act accordingly	"topic":"netio/${DEVICE_NAME}/output/1/action"
qos	mandatory	0, 1 or 2	MQTT's Quality of Sevice - definition {here|http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc442180912}	"qos":0
target	mandatory		internal definition of action, which can be performed above the specified output	"target":"OUTPUTS/1/ACTION"
action	mandatory		a payload or a value the action attribute needs to have passed to	"action":"${payload}"

Examples

Subscribe to more than one topic

Subscribe topic payload values specification for control of the output:

netio/<DEVICE_NAME>/output/1/action with payload for output control : (0 – off, 1 – on, 2 – short off, 3 – short on, 4 – toggle, 5 – no change)

Publish

when you need to send some data from device towards the broker, you have to specify it in the publish section - you can send measurement data as they are implemented, or you can use translation tables to send some pre-defined strings or even send JSON object. these attributes can be send periodicaly every time the timer reached specified value in seconds or based on value change (something like delta principle, but using only value differrence within defined period)

Hints to usage

When event send message with payload to topic.

Attributes table overview

Item	Presence	Possible Values	Description	JSON Config Usage
topic	mandatory	see table below	definition of the topic, how it is registered towards MQTT broker	"topic":"netio/${DEVICE_NAME}/output/1/load"
qos	mandatory	see table below	MQTT's Quality of Sevice - definition {here|http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc442180912}
retain	mandatory	boolean: true or false	MQTT's attribute to specify to broker how to store last received information - section 3.3.1.3 of {MQTT doc|http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc442180841}	"retain":true
payload	mandatory	see table below	definition of the topic, how it is registered towards MQTT broker	"topic":"netio/${DEVICE_NAME}/output/1/load"
events	mandatory	see table below	definition of events used for triggering sending of data via mqtt (change, delta, timer)

Target / Source

In MQTT-flex we use targets and sources specify where to apply some change or get value. Practically it means addressing of INPUTS/OUTPUTS and adding command or variable.

• source - specifies from where the value will be read (specifies the source of data for payload, change detection, delta calculation)
• target - specifies where the data should be sent or command applied (e.g. specifies the target for ACTION)

INPUT / OUTPUT (Target) selection

NETIO Devices can have inputs and outputs which can be different type. When you want to work with some variable you have to specify on which I/O. For doing that in MQTT-flex is implemented structured addressing with "/" separator. See the steps below how to compose source or target.

1. At first specify if requested variable is from/for INPUT or OUTPUT using keywords "OUTPUTS" or "INPUTS" .
2. Add "/" separator
3. Specify the number of INPUT/OUTPUT to 1(or TOTAL for summary statistics if available)
4. Add "/" separator
5. Specify requested variable or command

Note: Not all of OUTPUTS/INPUTS support all variables. Available variables are closely connected with the device functions and I/O features.

Note2: INPUTS not yet implemented

Examples:

adressing controll of output 3

OUTPUTS/3/ACTION

getting voltage on output 1

OUTPUTS/1/VOLTAGE

Variables

In some parameters is nescessary to use variables to get current state and measurements. Variables are separated in two categories:

• Target/Source variables
• Payload Topic variables

Target Source Variables

The list of available variables for each

OUTPUTS variables

Examples

"payload":"${OUTPUTS/1/STATE}"

"target":"OUTPUTS/1/ACTION"

"source":"${OUTPUTS/1/ENERGY}"

INPUT variables ^{Not yet implemented}

Not yet implemented

TOTALs - for future use with devices having more than 1 measured output

• OUTPUTS/TOTAL/ENERGY
• OUTPUTS/TOTAL/LOAD
• OUTPUTS/TOTAL/CURRENT
• OUTPUTS/TOTAL/VOLTAGE
• OUTPUTS/TOTAL/POWER_FACTOR
• OUTPUTS/TOTAL/FREQUENCY

Payload/topic variables

Examples

"payload":"${PAYLOAD}"

"topic":"netio/${DEVICE_NAME}/output/1/action"

Extended MQTT flex JSON config example

   {
       "config":{
          "broker":{
              "url":"broker.hivemq.com",
              "protocol":"mqtt",
              "port":1883,
              "ssl":false,
              "type":"generic",
              "username":"freedom",
              "password":"peace|LOVE|empathy4ALL"
          },
          "subscribe":[{
                 "topic":"netio/${DEVICE_NAME}/output/1/action",
                 "qos":0,
                 "target":"OUTPUTS/1/ACTION",
                 "action":"${payload}"
             }
         ],
         "publish":[
             {
                 "topic":"netio/${DEVICE_NAME}/output/1/state",
                 "qos":0,
                 "retain":true,
                 "payload":"${OUTPUTS/1/STATE}",
                 "events":[
                     {
                         "type":"change",
                         "source":"OUTPUTS/1/STATE"
                     }
                 ]
             },
             {
                 "topic":"netio/${DEVICE_NAME}/output/1/load",
                 "qos":0,
                 "retain":false,
                 "payload":"${OUTPUTS/1/LOAD}",
                 "events":[
                     {
                         "type":"timer",
                         "period":1111
                     },
                     {
                         "type":"delta",
                         "source":"OUTPUTS/1/LOAD",
                         "delta":1
                     }      
                 ]
             }
         ]
     }
 }