LoRa vs. Modbus Sensors: What to Choose for Your IoT Solution?

Our speakers thoroughly covered the topics of LoRaWAN and Modbus communication protocols, their respective advantages and limitations, and conducted a comparative analysis of LoRa and Modbus gateways for water tank level monitoring systems.

You have now learned about the distinctions between LoRaWAN and Modbus gateways in compact IoT networks and received valuable insights on how to select the most suitable gateway for your specific requirements, supported by real-life examples.

Webinar transcript

Anna: Let's just do a basic sound check. If you can hear me, guys, well, please let me know in the chat. I'm waiting for your messages. Just let us know if I'm audible, and you can hear me.

In that case, let's start! Hey everyone, it's great to have you here. Today's session is going to be a little different from the last one. Think of it as a KaaIoT tech chat.

As you may know, the KaaIoT platform was built to cover a variety of different use cases. And today, we have here with us Nikolai, a seasoned pro with over five years of KaaIoT platform mastery under his belt. He's got a wealth of experience across different industries and knows the ins and outs of building killer IoT applications. Hey everyone, hey Nikolai! Thanks for joining.

Today, we are ready to tackle your burning IoT questions, particularly those related to one of the hottest topics among our Kaa users: LoRa or Modbus sensor: Which one's the winner? We've hand picked this topic based on your popular requests, so we're hoping to spread some serious knowledge today.

By the way, we have an important announcement. Stick around until the end, because we've got an exciting little competition to announce. Okay, so you've got a front row seat on the solution delivery team. I'm coming more from a business perspective. You have all of the technical depth. Let's combine them today!

And let’s start by identifying who's going to benefit the most from this webinar. Can you shed some light on which industries or which use cases tend to bring up this LoRa vs. Modbus debate the most?

Nikolay: Thank you, Anna. So as you know, any IoT use case is based on sensors because sensors are the main information point in the IoT field. So if you want to understand a little bit more regarding sensors, I think this webinar will be a good place to start. What's the difference between Modbus and LoRa sensors? So I will not do a deep dive into the protocol difference, but at least I will be able to provide an overview of the use cases in which you should use LoRa sensors. And in which case you will need to use Modbus sensors.

Anna: Okay, so you know I was expecting more like that. You will say something like: Folks from industrial information or oil and gas fields, you know, stay with us. But it looks like this debate is more of a generic topic, which is quite good as well. Because, from my understanding, you cannot be radical and compare these two in general. It's not that black and white there. There are certain advantages of one technology over the other that can be applicable in this or that scenario. Am I correct at all?

Nikolay: Let's start to understand what the difference is.

Anna: So if you can let us know what makes this choice the smart one, what are the little details that matter in making this selection, and how do we go about it the right way? How do we select the appropriate sensor?

Nikolay: I suggest starting with Modbus. So let's start with a basic overview of what Modbus is. Modbus is a way to communicate to devices using wires. It's a pretty old protocol which is still very popular in the industrial field and many others. It supports different transports. So today, we will discuss two of them. Modbus RTU and Modbus TCP.

Let's start from Modbus RTU. What we have here is Modbus master and Modbus slave. There are two players. Modbus master: It's a device that reads information from this wave. So as you can see here, the green arrow means that it's started reading from Modbus slaves. Modbus slaves provide responses. And Modbus Master understands what information it gets.

What is Modbus RTU? Modbus RTU is a way to use the RS 485 interface to fetch information from a certain type of device. Also Modbus can use R232 but it's a too old interface, which leads to the limitation that we can't have more than one slave. You will have one master and one slave. Sensors are usually slaves. IoT gateways usually play the role of Modbus Master.

Also, there's Modbus TCP. So what's the difference between them? It's that it can use TCP/IP stack for the implementation of the Modbus protocol. We have some kind of computer that uses Modbus TCP. We have PLCs, sensors - it can be anything. So the same story but just using TCP/IP.

What's the difference between them? Modbus TCP mostly has unlimited ability to scale. You can have one master and as many devices as you need. With Modbus RTU, you have a limitation. Keep it in mind. Also if you use Modbus RTU, you have a lot of additional limitations like wires, quality of the wires, etc. With Modbus TCP, all these issues are resolved. Because everyone knows how the internet currently works. You just don't have any issues with this. This was a brief overview and maybe you have some questions.

Anna: Well, you said that RS 485 is pretty old but still popular. Much like some people, right? But you know in the tech world, new things are usually better than the old ones. Can you explain why people still use it?

Nikolay: Sure, there's a variety of sensors. If you even now open any marketplace where you type IoT gateway, I'm sure that you will be able to find a RS 485 interface on half of them. And even new IoT gateways support it. Because the variety of the sensors is pretty huge. And usually all IoT systems or Industrial Automation systems go through evolution. So for example you decide to replace only the gateway but you want to keep all the sensors. And manufacturers of these IoT gateways provide opportunities to connect them. And also new sensors, a lot of new loT sensors also support this interface. This is why.

Anna: So can you go through like LoRa pros and cons and the same for Modbus.

Nikolay: Let's also stop for a little bit here before moving to LoRa. What does an IoT solution usually look like? We have multiple sensors as we previously discussed. We have an IoT gateway and we have an application. In our case, it's Kaa Cloud which is used by the IoT gateway for pushing data and after that, building an IoT solution. Let's start from LoRa.

Before we start, I just want to explain some technical words. So what is LoRa itself? It's a way to transfer information and have communication between different devices using a radio channel and LoRa modulation.

It's a way how you use radio frequency to encode some piece of information. What words should you know? You should know LPWAN. LPWAN is a low power wide area network.

It's a wireless communication network where you have a gateway and you have some devices which can communicate with each other. What is the limitation of LPWAN networks?

It has a pretty low bitrate. So for example, if you want to transfer a lot of information from your sensors and fetch information pretty frequently, LoRa won't be your solution. The implementation of LPWAN using the LoRa tech stack is called LoRaWAN. So let's go to this slide and I will explain a little bit about what we can see here. As you can see here, we have different standards like U868, U433 and others. It's pretty important to understand which standard is used in each of your sensors. Because your gateway and your sensors should be compatible. The LoRa modulation part, I think, is clear. So what about LoRaWAN. We have different classes of devices. The difference between them is the amount of data that you can transfer, which means bitrate. And also how much power they require to work, and application.

In our case, it's Kaa Cloud but it can be The Things Network or other network server which transfers information to the IoT system or other system, and you can build your solution.

Let's see architecture and how it looks. We have end nodes, we have a concentrator/gateway, we have a network server and application server. So, the variety of sensors is also pretty huge, and you will be able to find LoRa sensors for any use case. And also gateways, mostly all of them are available.

So let's summarize everything. So if we compare Modbus, well, it's pretty hard to compare, because it's like comparing a wired solution and a wireless solution. But if we see Modbus sensors, they are much cheaper, compared to LoRa. The variety is much bigger and the variety of IoT gateways is also much bigger. The main minus of Modbus is that it's wired. There are limits on connection of devices if you use Modbus RTU. And usually it requires an external power supply. So in some cases, it's not acceptable. LoRa is wireless and low power. Sensors can be used without external power supply but it's much more expensive and if you have a case when you need to transfer a lot of information from the sensor, it's also not applicable.

Anna: Okay, thank you so much, Nikolay. That was a wealth of information and I'm sure that everyone found it super helpful. And don't forget, guys, we are interested in getting the real discussion going. I can see some conversations already in the chat, and this is awesome. Please, post your questions here because later, we're going to have a Q&A session. We're

going to answer all of your questions. Well, we'll try to at least, right. Depends on how many questions you're going to ask. But for sure, we will cover most of these.

Okay so now let's shift our gears from theory to practice. It would be awesome if we could take a more practical look into one of the use cases built on top of Kaa platform. Nikolay, if you have any of these prepared, it would be great to switch to the practice.

Nikolay: Sure, I was prepared for this webinar, so I will explain one of our popular requests we get from our customers. It's pretty simple but I will explain that you will be able to use these sensors and these sensors but based on different inputs, in which case it's better to use LoRa and in which case it's better to use Modbus.

Let's start by describing a use case. It's a water monitoring system for the water tank. So you have a tank, you have a sensor. Here we have an example which shows the schema for Modbus. But the same story will be for LoRa. So we will also have a tank and we will also have a water level sensor.

So let's start our discussion with Modbus. What will we have? We use sensors that are connected using RS485, we have our IoT gateway which supports Modbus RTU and it plays the role of Master. An IoT gateway transfers information to our KaaIoT Cloud using MQTT. So we use a regular server network, 3G/4G which is available. So everything is pretty simple. You just need two components: this sensor and gateway. In our case, it's Teltonika. It's a pretty good choice if you live in Europe.

Let's see what's the difference between LoRa, so for example if I will scroll here, it will be the same but because our platform does not support direct connection, so it can't play a role of the LoRaWAN network server. In this case, you should use Node-RED.

By the way, we provide managed Node-RED service which you can enable in your tenant and just connect your sensors using special Node-RED nodes. And we also provide special Node-RED nodes for integration and MQTT integration with KaaIoT. So we have the same story here. We have sensors, we have a LoRa gateway and we have Node-RED and we have KaaIoT.

So this was a brief overview. Let's move to the UI part. I think, without this, we can't move further. And I will show what it can look like on our platform.

Anna: I also wanted to mention that some of our clients who are using Teltonika devices, it's not only for Europe. It's just that you said: if you're in Europe you'd better use this one. But we have clients from other regions who are using these devices and it works like a charm.

Nikolay: Just be careful when you select a Teltonika device, which server network it supports because in the USA, there is a difference between Verizone, AT&T, they use different protocols. Sorry, not protocols – different bands and sometimes, it just doesn't work. But in Europe, we never face these issues.

So what do we have here? We have an example of a solution, how it can look like. Where we have a home dashboard with a sensor location. It can be changed to a LoRa gateway. It's not a problem. We have event logs. You can change status, you can get information regarding level. It's automatically calculated by the system. You can get a percentage. You can see graphs, map, location, device metadata. And what's most interesting is that this part took me around 10 minutes to configure before this webinar. So it was a short demo but, I think, it can provide an idea on how to easily configure any solution with our platform.

Anna: Wow, thank you so much, Nikolay, for this great overview. I know that you can talk about this for ages or hours, right? But we don't want to get bored. So we were trying to make it as short and efficient as possible. This discussion, Modbus versus LoRa, really reminds me of the wireless vs. cable topic. While all of this might seem a bit overwhelming and I'm not an engineer like you. But I will try to summarize everything said. And please correct me if I'm wrong. I'm just trying to get some quick pointers here.

If the product is located inside of the building, then Modbus, if outside the building, you'd better use LoRa. If you need to send information once per minute, LoRa would work better than Modbus. If you need information to be sent every 5 seconds, for example, it might create a problem. What else? Price for Modbus devices is much lower than for LoRa devices. And also, depending on the distance between objects, it's also important. For example, if objects are located on a bigger distance between each other, I think, LoRa would be the better fit. And if they're close to each other, then Modbus: for sure, good to go. So that's what I've taken from your speech.

Nikolay: You are not a technical specialist but you understand everything exactly as I wanted to explain. That it's mostly based on your scenario. As you mentioned, if it's located inside of the building, wireless technology usually doesn't work well because of the walls. Depending on the wall and depending on the structure of the building. You're absolutely right. Well, as far as I understand, the Kaa platform can be a foundation for a solution for pretty much any type of device.

Anna: But for me and for our users, I know that the trick can be sometimes in getting these devices integrated smoothly. So the integration is the first step. And do we have any additional materials to share with people? For example, on how to integrate Modbus and LoRa sensors. I heard that you were working on something. Can you show us?

Nikolay: Of course! If you think that this will be all the information our webinar's attendees get, you are absolutely not right. We have prepared two pretty technical instructions on how to connect LoRa sensors and Modbus sensors with real gateways, with real examples, with the screenshots. So all of these things you can find on our website, kaaiot.com, under Blog. And you will be able to see LoRa and Modbus.

Here, we explain how to connect real sensors with some technical explanation just for understanding. We use a Teltonika device because usually, you can buy it in any country. And how to configure our platform to get information and start building your solutions. The same story we provide with LoRa. We use Dragino gateway which is an old technical device because it's also cheap and more popular. But for all of the visitors, if you have your own gateway and our own sensors which you have struggled to connect to our system, we are always open. Just write to Anna, and we will resolve it and create documentation. And everything will work, and you will get success with our IoT solution.

Anna: Okay, thank you so much! I'll make sure that we're going to post it also on social media, all of these links to the blog, to these articles, so that you guys do not miss any of these. All right, thank you! It was quite a cool discussion. Very helpful!

Maybe we should switch to the Q&A session. Because I saw a wild discussion going on. I don't even know where to start.

Yes, this meeting is recorded, and we're going to share the recording after the webinar.

Based on your expertise, what are your recommendations for selecting between LoRa and Modbus sensors in different scenarios. Well, I think we covered this, but maybe shortly, Nikolay, you can just summarize.

Nikolay: As we previously mentioned, it's a discussion: wireless solution and wired solution. So if you have big ranges... Because LoRa has pretty good coverage. ... and your sensors are not located nearby, I think LoRa will be a good solution. If you have a solution which should be located indoors, I think Modbus will be better.

And also, based on your solution, sometimes you will not be able to find some sensors using LoRa. And you can just easily mix them. So you can have LoRa sensors and you can have Modbus sensors. You can have just two gateways and after that, join all this information in your IoT platform which is KaaIoT.

Anna: How does it handle authentication? Is it possible at all?

Nikolay: Yeah, with LoRa, it has a pretty advanced authentication system. I think you will be able to find all these questions answered within our articles. Because it will take a couple minutes only to start an explanation of how it works for Modbus. It's usually local systems and it doesn't have a well-designed authentication system. From this perspective, I think LoRa will be a better solution from the security perspective.

Anna: Hi from Poland! What are the main differences between Modbus RTU and Modbus TCP, and how does one choose between them for sensor communication.

Nikolay: Yeah, it's a good question. These are different transports. You can use serial communication or you can use TCP/IP stack. From my point of view, it's much better to use TCP/IP stack but it's usually more expensive. And, for example, if you need to make a simple IoT solution with simple sensors with a cheap gateway. In this case, it will be easier to use Modbus RTU. But, for example, if you need to connect too many devices and you don't want to struggle with the wires, frequencies and all this stuff. I think that Modbus TCP will be right for your solution.

Anna: Can LoRa and Modbus sensors work together within the same IoT ecosystem? Sure, as I previously mentioned, our IoT platform is fully device agnostic. We provide an MQTT interface. And if your gateway can connect the sensors and publish this information to the MQTT topic, you will not face any issues with the integration. So feel free to mix them. Feel free to connect.

Anna: How do LoRa and Modbus sensors handle data transmission in different environments and conditions?

Nikolay: Usually, the most stable solution, it's a wired solution. I think it's clear for everyone. But there are some surprises with Modbus. Modbus has different communication options like frame and other things, which can make it also not as stable. Especially when you have connected a lot of sensors. But once you configure it, usually, wired connection is much more stable. But it also has some additional points. For example, usually, LoRa sensors are designed to be placed outdoors. But with Modbus sensors, you should be really careful there.

Anna: Okay, one more from Shivam. Can you explain how these edge device will convert data received from LoRa devices into Modbus TCP format.

Nikolay: I'm sure that some device can do this. But I don't know such devices. Usually how it works, you have a network server which is used by Lora to publish information. And after that, you publish this to your IoT platform. And after that, you have some Modbus sensors with a Modbus Master which usually plays the role of an IoT gateway that is publishing information. And after that, you merge all this information in an IoT platform and build a solution on top of the data from LoRa and Modbus sensors.

Anna: Which technology is more power-efficient for battery-operated IoT devices?

Nikolay: Of course, it's LoRa. Usually, sensors have a power supply with a small battery, and they can work for years without changing or charging this battery.

Anna: Okay, thanks, Nikolai. I can see that we have ran out of questions but we have a lively discussion going on, which is also cool. Okay, so it was great! I think we are already coming to the end of the webinar.

As we promised at the beginning, a little announcement. We decided to make things interesting for Kaa users and we want to see if the information shared is useful to you. So we'll be offering a complimentary three-month subscription for 15 devices on Kaa Cloud to the first three individuals who connect their LoRa or Modbus devices and let us know the feedback. So to help you get started, we have a free two-week trial period and technical information, the webinar, we have some articles that our technical team wrote for you. All of the info at your disposal. So let's see. We're gonna publish on our social media pages the winners.

Okay, we have one more question coming. Nikolay, are you ready to get on it?

Which solution is suitable for industrial applications: LoRa or Modbus. As I know, most of the industrial equipment has the Modbus protocol built-in.

Nikolay: You are absolutely right. Based on our experience, usually on industrial IoT, you should use Modbus because all of the sensors inside your equipment support this protocol. And it's much easier. But you can also mix it. For example, if you want to fetch information from the equipment, I think, you will have some PLCs that control the work of your equipment and usually, it can play the role of a Modbus slave. and you just fetch information there. But it isn't a problem to mix it. There are various sensors and various use cases. If you just want to install, you can use Lora for this. But yes, you're right. For industrial, Modbus is currently much more popular.

Anna: Guys, if you're facing any challenges with your IoT project and need advice – whether industrial or something else. Don't hesitate to get in touch. Do not forget to connect your devices to the KaaIoT platform. Let us know how it goes. And if you need any help, we are here to support you.

So stay tuned, be real, and everything will be IoT. Thank you so much for joining us! Nikolai, thank you for the great presentation. Stay updated. We are going to have another webinar coming soon with one of our clients with environmental monitoring.

We're looking forward to seeing everyone there!

Thank you, guys. Bye!