Modbus Monitoring with PRTG

Improve the reliability of your industrial network

Use Modbus TCP/IP and Modbus RTU protocols for comprehensive monitoring
Ensure reliable communications between Modbus devices
Set preventive maintenance tasks in place before potential issues escalate

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product overview

Paessler PRTG is trusted by 500,000 users worldwide

PRTG modbus monitoring: What you will find on this page

Keep your Modbus network talking
What Modbus monitoring looks like in PRTG
5 reasons to choose PRTG as your Modbus monitoring tool
Explore our preconfigured PRTG sensors for modbus monitoring
Monitoring Modbus: FAQ

PRTG makes Modbus monitoring as easy as it gets

Custom alerts and data visualization let you quickly identify and prevent OT network performance issues.

Free download

PRODUCT OVERVIEW

Keep your Modbus network talking

Modbus, initially used in industrial manufacturing, is now in almost every sector, including cloud services, e-health, security, telecommunications, and even farming, among others. Whether your IT systems use Modbus RTU or Modbus TCP-enabled devices, having a 24/7/365 watchdog on your Modbus network is critical to business continuity. Paessler PRTG Modbus monitoring is your solution to keep Modbus data transfer and your Modbus communications going strong.

Simplify your complex IT/OT network

Networks can be complex, and networks using Modbus-enabled devices are no different. Modbus monitoring simplifies the complexity by standardizing communication protocols across diverse devices.

This unified platform helps you monitor and manage all your IT and OT network components in one place without worrying about different device languages and protocols.

Blur the lines between legacy & new systems

As a systems engineer, you deal with traditional IT devices, edge networks, and even operational technology infrastructures. One of the concerns with any software is how it will work with your converged IT ecosystem.

Modbus monitoring easily integrates new and existing systems, allowing your organization to scale efficiently. By simplifying communications between devices, Modbus monitoring makes integration and interoperability seamless.

Say goodbye to long downtimes

Long downtimes mean lost productivity, lower revenue, recovery expenses, and more. The average cost is estimated at around $5,600 per minute, according to Gartner.

Modbus monitoring quickly pays off by significantly enhancing system reliability. Real-time data collection and an immediate alert system help stop network issues before they escalate.

Increase operational efficiency

Efficiency doesn’t have to be a four-letter word. PRTG Modbus monitoring gives you real-time visibility into how your Modbus-enabled devices are doing.

With automated data collection and analysis, time spent manually doing systems checks can now be freed up for more important tasks, such as optimizing processes and improving operational workflows.

Keep your systems secure

IT/OT network security is a matter of real concern for industrial organizations. Monitoring using Modbus provides continuous oversight of your network communications and device behavior.

With round-the-clock monitoring, logging, and analysis, you can identify potential security breaches early and quickly respond, maintaining the integrity of your systems. This is also important for meeting governmental regulations regarding network security, for example, the European NIS-2 Directive.

What Modbus monitoring looks like in PRTG

Diagnose network issues by continuously tracking your Modbus RTUs and other devices. Show system performance, statistics, troubleshooting information, and other custom metrics in real time. Visualize monitoring data in clear graphs and dashboards to identify problems more easily. Gain the overview you need to troubleshoot Modbus communications and other issues in your OT network.

Start monitoring Modbus systems with PRTG and see how it can make your network more reliable and your job easier.

Free download

PRODUCT OVERVIEW

An award-winning extension for Paessler PRTG to bridge IT and OT, as voted by readers

Awarded 3rd place in the
Software & IT category

Winner in the Software &
Computers category

5 reasons to choose PRTG as your Modbus monitoring tool

Get an all-in-one monitoring solution

With Industry 4.0, the number of IIoT devices is constantly increasing. The focus is, for example, on intelligent gateways, devices for monitoring temperature and humidity, and the availability and status of PLCs.

With PRTG as an all-in-one monitoring solution, you always have a complete overview of all devices in your IT, OT, and IIoT infrastructure, and can be notified individually according to defined values.

Monitor hyper-converged IT/OT networks

With PRTG, you can integrate a comprehensive set of features with ease of use and maximum flexibility. In addition to out-of-the-box support for all common IT standards, PRTG offers a RESTful API as well as MQTT, OPC UA, and Redfish support.

Easily integrate shop floors, IoT devices that monitor environmental parameters, and other IT devices and applications that do not use conventional technologies into your monitoring setup.

Benefit from specialized Modbus sensors

PRTG comes with Modbus sensors out of the box to monitor devices that support Modbus RTU or TCP. Use, for example, the Modbus TCP Custom sensor to monitor values that your Modbus TCP server returns. With this sensor type, you can monitor cooling units, power supply, backup generators, and other peripheral devices.

Our Modbus RTU Custom sensor connects to a Modbus RTU server and monitors up to five returned numeric values, for example, the temperature and humidity of devices.Tell the reader more

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Monitor more in your Industrial IoT

PRTG extends its traditional network monitoring capabilities by monitoring devices over the Modbus TCP protocol. Monitor the availability and status of PLCs and SCADA systems, temperature and switching status of Modbus devices, and power consumption metrics like usage, capacity, voltage, and frequency.

Integrate data from critical structures like HVAC systems and uninterruptible power supplies (UPS) into a central monitoring solution.

Take your monitoring one step further

Go beyond checking how efficient your IT assets are operating. PRTG also gives you comprehensive oversight into the environmental conditions of your data center and the stability of your energy metering systems.

By monitoring the physical conditions, you have the information to ensure optimum data center performance, prevent costly downtime, and provide preventative maintenance.

Explore our preconfigured PRTG sensors for modbus monitoring

PRTG comes with more than 250 native sensor types for monitoring your entire on-premises, cloud, and hybrid cloud environment out of the box. Check out some examples below!

Modbus TCP Custom

The Modbus TCP Custom sensor connects to a Modbus Transmission Control Protocol (TCP) server and monitors up to ten returned numeric values. It can show the following:

Downtime
Custom numeric values

Modbus RTU Custom

The Modbus RTU Custom sensor connects to a Modbus Remote Terminal Unit (RTU) server and monitors up to ten returned numeric values. It can show the following:

Downtime
Custom numeric values

SNMP Rittal CMC III Hardware Status

The SNMP Rittal CMC III Hardware Status sensor monitors the overall status of Rittal data center hardware, for example Rittal Computer Multi Control version 3 (CMC III) processing units, Rittal power distribution units (PDU), or Rittal IoT interfaces. It can show the following:

Overall device status
Attached external sensor status

Beckhoff IPC System Health

The Beckhoff IPC System Health sensor monitors the system health of a Beckhoff Industrial PC (IPC) via OPC Unified Architecture (OPC UA). It can show the following:

Available memory
CPU load
CPU and mainboard temperature
RAID controller status

See the PRTG Manual for a list of all available sensor types.

PRTG is compatible with all major vendors, products, and systems

Find the root cause of the problem with our PRTG Modbus monitoring software

Real-time notifications mean faster troubleshooting so that you can act before more serious issues occur.

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PRODUCT OVERVIEW

“PRTG has become an essential part of the entire plant production process, from planning to acceptance by the customer. So much so that we are currently toying with the idea of expanding our portfolio to offer support for plants, even after they are operational.”

Frank Schweisfurth

SMS group

“We have known PRTG for many years. We have selected this solution because it integrates natively into the industrial operational technology environments that we offer to our customers in the region.”

Miguel Ángel López Ávila, General Manager

SE3

“We appreciate the flexibility of PRTG and how it grows together with the company, supporting our needs to also digitalize the factory floor and monitor not only standard IT infrastructure but also factory equipment.”

Sandeep Rai, Network and Security Team Lead

Nobia AB

“In the past, the enterprise and the industrial network were completely separated with very different requirements, such as security versus productivity. We see that within OT, monitoring is not widely used yet for several reasons, but processes are depending on IT systems more and more. The need for a reliable OT network is growing rapidly, and that’s where PRTG comes in.”

Pascal Vercammen, Digitalization & IT Department Manager

Process Automation Solutions

Your Modbus monitor at a glance – even on the go

Set up PRTG in minutes and use it on almost any mobile device.

“Excellent tool for detailed monitoring. Alarms and notifications work greatly. Equipment addition is straight forward and server initial setup is very easy. ...feel safe to purchase it if you intend to monitor a large networking landscape.”

Read the complete review at Gartner Peer Insights

Create innovative solutions with Paessler’s IT partners

Partnering with innovative IT vendors, Paessler unleashes synergies to create
new and additional benefits for joined customers.

Rittal

IT that works constitutes a business-critical basis for a company's success. Availability and security must be defined for the respective purpose and closely monitored – by OT and IT alike.

NetBrain

Integrating monitoring results from PRTG into NetBrain maps makes the foundation for network automation.

ScriptRunner

With ScriptRunner Paessler integrates a powerful event automation platform into PRTG Network Monitor.

PRTG makes Modbus monitoring as easy as it gets

Custom alerts and data visualization let you quickly identify and prevent OT network performance issues.

Free download

PRODUCT OVERVIEW

Paessler PRTG

Network Monitoring Software – Version 25.2.106.1114 (May 05th, 2025)

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Modbus Monitoring: FAQ

What is Modbus?

Modbus is a data communications server-client protocol originally for use with programmable logic controllers (PLC). It’s become a standard communications protocol, commonly available to connect industrial electronic devices. Free and openly published, Modbus is popular in industrial environments and many other industries. PRTG offers two native Modbus sensors, the Modbus TCP Custom and the Modbus RTU Custom sensor.

How does Modbus work?

Communication modes

Modbus operates in two primary modes:

Modbus RTU (Remote Terminal Unit): This is a binary communication protocol used in serial communication (e.g., RS-232, RS-485). It is compact and efficient, ideal for real-time communication.
Modbus TCP/IP: This version is used over Ethernet networks and is essentially Modbus RTU encapsulated in an Ethernet frame. It is used in modern networks where devices are connected over TCP/IP.

Master-slave architecture

Master device: This is typically a PLC (Programmable Logic Controller) or a computer running SCADA software. The Modbus master initiates communication and controls the conversation by sending requests to slave devices.
Slave devices: These could be sensors, actuators, or other field devices. Modbus slaves respond to the master's requests and provide data or take actions based on the master's instructions.

In a typical setup, one master can communicate with multiple slaves, each identified by a unique address.

Data frames and communication

Modbus communication is based on a request-response model, where the master sends a request frame, and the slave responds with a response frame. The frame structure is different for Modbus RTU and Modbus TCP/IP, but the core principles are similar.

Request frame: The master sends a request containing the slave address, function code, data (like register addresses or command parameters), and a CRC (Cyclic Redundancy Check) for error checking.
Response frame: The slave device processes the request and sends back a response containing the requested data or an acknowledgment of the action performed.

What is Modbus monitoring?

Modbus monitoring keeps a continual watch on your Modbus network. It provides real-time data analysis, allowing more informed decision-making. By integrating Modbus RTU and Modbus TCP into PRTG and monitoring it, you can get information about the status of PLCs, HVAC systems, detailed information from energy metering systems, and much more.

How is Modbus TCP different from Modbus RTU?

Both are Modbus protocols, but they have different uses. Modbus TCP is suitable for modern Ethernet-based industrial networks and is designed for TCP/IP network communication. Modbus RTU, on the other hand, uses RS-232 or RS-485 serial communication and is more common in legacy systems or limited network structures.

Do PRTG Modbus sensors impact the performance of my Modbus network?

No. PRTG Modbus sensors have a very low-performance impact.

What is a sensor in PRTG?

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, for example the traffic of a switch port, the CPU load of a server, or the free space on a disk drive. On average, you need about 5-10 sensors per device or one sensor per switch port.

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Monitor your entire IT infrastructure

Bandwidth, servers, virtual environments, websites, VoIP services – PRTG keeps an eye on your entire network.

Try Paessler PRTG for free

Everyone has different monitoring needs. That’s why we let you try PRTG for free.

Start monitoring Modbus systems with PRTG and see how it can make your network more reliable and your job easier.

Free download

PRODUCT OVERVIEW