KMTronic Plug-in and Creating Devices on HomeSeer HS3

We already have a HomeSeer plug-in for Sonoff's with Tasmota firmware which works great and we use it all the time, but sometimes WiFi isn't good enough especially for controls outside of the home or in a situation where reliability is important. For these cases we introduce the KMTronic Web Relay, an Ethernet based 8 relay device with optional DIN mounting. With the Web Relay we can control 8 individual relays using HomeSeer and our KMT Plug-in. We already use these both inside and outside of the building and find them very reliable and cost effective especially as compared to devices such as the Adam 6060 at 5 times the price. Likewise, sometimes temperature measurement is required with a degree of reliability and flexibility, such as monitoring external temperature, or water temperature. The one-wire DS18B20 is an established and reliable sensor available in many form factors and each LAN-DS1820 unit can support up to 4 of these. 


You can purchase both of these excellent devices from KMTronic Ltd in Bulgaria. If you use coupon code ST2708K46 then you will get 20% discount on your order which is outstanding value. 

There are currently two version of the Web Relay unit

These are high quality, reliable and cost effective units for load control over Ethernet. We can offer you a 20% discount on these units so please contact us (via this site or on the HS3 Forum) for a discount code. 

There is currently only one version of the Temperature Module and it works like this

Both of these devices require 12V DC to power them. You can use an AC Adapter, DIN Rail PSU, or if you prefer use POE with the addition of a TRENDNet TPE-104S or similar. Personally I use the TPE-104S and power everything over ethernet. 

The Plug-In

The KMT Plug-in can be found in the HomeSeer Plug-ins directory under "Analog & Digital Input/Output Device". 

Note: These instructions are for Version 1.055 and later (shown in HS3 as If your using an earlier plug-in then please update before proceeding. 

Configuring the Plug-in

Unlike some plug-ins, GEN plug-in's don't create or delete any devices themselves. Device creation, renaming, deleting and modifying is entirely up to you. Its done like this because in my relatively short time of using Homeseer I've found that plug-ins which create/delete their devices have two things in common, firstly they delete and re-create devices after an update, config change, or just for no reason at all which breaks all my events, and secondly because some plug-ins create a mountain of devices most of which I don't want to see. Having complete control over my devices and knowing they aren't going to change ref and mess up all my events is the reason its done like this. If you'd prefer the plug-in create the devices for you then feel free to make that known as nothing's fixed in stone. 

Creating Binary (ON / OFF) devices for the KMT Plugin

The 8 Channel Web Relay Board from KMTronic support binary (on/off) controls for each of the 8 outputs. These outputs are numbers 1 through 8. You can create all 8 devices or just the ones you need and add more in the future. In this example here we're going to create a device that relates to the first relay on a device at You should of course substitute your IP address of the web relay and relay number when creating devices yourself. 

Firstly login to Homeseer's Web Interface and select View and Device Management. Then click the Green + symbol at the top right and you should get the screen below. 


Give your device a name, it matters not what it is but it should describe the device or purpose to some degree. In our example we're going to call it Side Light. Give it a Floor and Room as usual. If you want this device to be controlled by voice then tick the Voice Command box. If you want to give it a picture then click "Select Device Image" and give it one. Now move onto the Advanced Tab

In the Advanced Tab click the "Device Type (String)" Box and the usual Edit Value box will be shown. This is where the magic happens. In our example we're going to be talking to the first relay (relay 1) on a device at To configure this we enter a Device Type (String) as 


As below

The Device Type (String) is the key to this working. The format is KNT: followed by the IP Address you gave the device, a forward slash /output and finally the relay number, which in this case is 1. Its important to get the KNT: in upper case or it won't work. Press OK and now move onto the Status Graphics Page. 

And your all done so click DONE and your device will be created.

Repeat the above steps to create devices for all your units and relays. Here's an example of all 8 relays setup, albeit with different IP's. You can see that I've named some of the relays something useful and the rest are unused but I've still created them for the future. 

The only part here that matters is the TYPE column (Device String) and you can see that we've got a device here at with relays from output1 through 8 setup. 

When the plug-in loads, it will search all your devices for those with KNT: in the device string. When it finds these it will add them to its list of managed devices and create associations between HS3 and the web relays. 

You can always check the Web Relays have been detected successfully by selecting Plugins then KMT then Config from the HS3 web interface. This will bring up a screen similar to the one below:

Creating Sensor devices for the KMT Plug-in

So each LAN-DS1820 device can support up to 4 temperature sensors but you need only configure the ones you're using. In our case we've used 3 of the 4 sensors. 

Firstly login to Homeseer's Web Interface and select View and Device Management. Then click the Green + symbol at the top right. Give the device a sensible name and give it the usual room and floor and then TICK the "Status Only Device" box, and untick "Voice Command" then move onto the Advanced Tab. 

In the Advanced Tab click the "Device Type (String)" Box and the usual Edit Value box will be shown. In our example we're going to be reading from the first sensor on a device at To configure this we enter a Device Type (String) as 


As below

Now move onto the Status Graphic Tab which is actually more important about how we represent the value from the sensor. You'll need to remove anything currently in there and then add a New Range Value

Give it a sensible range, in my case its -50 to 50 which covers any reading we're likely to get from the sensor. My suffix is "c" and I want two decimal places and then click STATUS under Status Control. 

Now add a New Range Graphic. In this case the choice is yours how you want this shown, and in this example we're just going for one graphic for the whole range (-50 to 50) but you can of course have a blue icon from -50 to 0, then a green icon from 1 to 20 and a red icon from 21 to 50 but here we're keeping it simple and I'm going to use a graphic from the OMNI plugin which I do like. 

And now you can go ahead and click DONE. When you've setup all your sensor devices your going to see something like this

You'll notice that our icon and temperature are formatted perfectly, but you can of course change this to meet your requirements.

The Scale for Temperature measurement can be selected in the CONFIG section of the Plug-in. Change the scale and then SAVE. After SAVE is confirmed, then disable and re-enable the plugin for the changes to take effect. 

Now re-load the plug-in and you should see in the plug-ins Config Tab all your newly created devices along with their type and state. If you find one or more of your configured devices missing then re-check the Device String on the Advanced Tab is correctly formatted. 

IMPORTANT: Application Note; The KMTronic Web Relay is designed for resistive loads such as lights and heaters. If your going to use it with Motors then an additional capacitor (600V 680nF) should be fitted between the Output and Neutral to ensure long life of the relays. Be sure to insulate the legs of the capacitor with heat shrink where exposed. 

For some background and an overview of Design and Development Follow this link