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Modbus Examples

John Cocula edited this page Dec 29, 2016 · 1 revision

The page contains examples for use with the Modbus binding.

Table of Contents

Rollershutter Items

Since Modbus is a low-level protocol, more abstract concepts like controlling roller shutters can be implemented in a number of different ways. This example (offered by @ssalonen here) is one approach using openHAB rules and the standard Modbus binding. Adapt it to your needs, and please edit this wiki page to correct and clarify this example.

default.rules

import org.openhab.core.library.types.DecimalType
import org.openhab.core.library.types.PercentType
// comment out the above imports if running on openHAB 2+

rule "Process roller shutter commands"
when
    Item myRS received command
then
    logInfo("rollerShutterRules", "Processing RS command")
    if(receivedCommand != null){        
        switch(receivedCommand.toString.upperCase) {        
            case "UP" : {
                sendCommand(myRSUpDown, 1)
            }
            case "DOWN":{
                sendCommand(myRSUpDown, -1)
            }
            case "STOP":{ 
                sendCommand(myRSMoveStop, 1)
            }   
            case "MOVE":{
                sendCommand(myRSMoveStop, 0)
            }
        }
    }
end

rule "Update roller shutter position"
when
    Item myRSMoveStop received update
then
    logInfo("rollerShutterRules", "Processing position update")
    var currentPosition = myRSMoveStop.state as DecimalType
    postUpdate(myRS, new PercentType(currentPosition.toBigDecimal))
end

default.items


// Main roller shutter item. 
// - State will be updated from register index 0. 
// - Up (1) & Down (-1) commands will be written to register index 1
// - Move (0) & Stop (1) commands will be written to register index 2
Rollershutter myRS "RollerShutter" (livingRoom)

// Helper items for writing data to MODBUS
Number myRSUpDown "RollerShutter Up/Down Control (writing to index 1, read from index 0)" (livingRoom) {modbus="slave1:<0:>1"} 
Number myRSMoveStop "RollerShutter Move/Stop Control (writing to index 2, read from index 0)" (livingRoom) {modbus="slave1:<0:>2"} 

default.sitemap

sitemap demo label="Main Menu" {
    // https://github.com/openhab/openhab/wiki/Rollershutter-Bindings
    Switch item=myRS label="Roller shutter [(%d)]" mappings=[UP="up", STOP="X", DOWN="down"]
    Text item=myRSMoveStop
    Text item=myRSUpDown
}

For local testing

Starting up modbus tcp server (i.e. modbus slave)

./diagslave -m tcp -p 55502

openhab.cfg (openHAB 1.x)

modbus:tcp.slave1.connection=localhost:55502:0:0:0:1
modbus:tcp.slave1.type=holding
modbus:tcp.slave1.length=20
modbus:tcp.slave1.postundefinedonreaderror=true

modbus.cfg (openHAB 2+)

tcp.slave1.connection=localhost:55502:0:0:0:1
tcp.slave1.type=holding
tcp.slave1.length=20
tcp.slave1.postundefinedonreaderror=true

As inspiration I used Roller shutter wiki page

Table of Contents

feature overview

Installation

Setup intro

Linux and OS X

Windows

FreeBSD


Configuration

Automation*

User Interfaces

Persistence


Community

(link to openHAB forum)

Development


Bindings


Application Integration

Misc


Samples

A good source of inspiration and tips from users gathered over the years. Be aware that things may have changed since they were written and some examples might not work correctly.

Please update the wiki if you do come across any out of date information.

Binding configurations

Use case examples

Item definition examples

Sitemap definition examples

Collections of Rules on a single page

Single Rules

Scripts

Syntax highlighting for external editors


Release Notes

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