Published by Sascha Neumeier
Last updated on June 26, 2025
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14 minute read
Have you ever faced production downtime when an unknown sensor in your OT setup stopped working unexpectedly? You likely faced management questioning after discovering an unauthorized two-hour break in your FDA-required pharmaceutical cleanroom temperature log. The fact that you're nodding along means you're in good company within the unpredictable domain of Operational Technology monitoring. 🫠
Monitoring OT environments presents extreme difficulties comparable to herding cats while managing flaming torches. The combination of outdated equipment from before smartphones existed and networks with more divisions than millipedes makes it astonishing that monitoring efforts succeed at all.
Fellow sysadmin don't worry because we'll explore the top five OT monitoring headaches today with Paessler PRTG Network Monitor as your industrial-strength solution.
Challenge 1: Legacy equipment with no modern interfaces
Doesn't anyone else know about the PLC from 1995 that still manages essential operations? The PLC documentation survives only as a coffee-stained printout buried in a desk drawer. Although legacy equipment remains essential infrastructure in industrial operations it communicates in languages that contemporary monitoring systems cannot comprehend.
The PRTG solution: PRTG enables monitoring of industrial control systems by supporting Modbus TCP as its primary communication protocol. You can keep an eye on outdated PLCs and controllers with this protocol without needing to invest in costly system replacements. The Modbus TCP Custom sensor provides the functionality to collect up to five separate metrics from any Modbus-compatible device which enables visibility into equipment normally beyond monitoring capabilities.
You can track temperature sensors, valve positions, motor speeds, and error states from equipment that existed before the cloud became a tech concept. A manufacturing client implemented PRTG's Modbus capabilities to supervise a 20-year-old production line which resulted in savings of over $200,000 by avoiding unnecessary equipment upgrades while fulfilling current monitoring needs.
Challenge 2: Protocol incompatibility
When working in OT, you're likely dealing with a United Nations of protocols: Modbus data must pass through OPC UA before it reaches MQTT which needs to find a way to connect with the SNMP-based IT monitoring system. You have to host an international dinner party where every guest speaks a different language while you alone must translate everything.
The PRTG solution: PRTG offers unified monitoring capabilities for Modbus TCP, OPC UA, and MQTT without needing any intermediate converters or middleware. Multi-protocol support enables full monitoring of your OT environment through one unified interface.
The OPC UA sensors in PRTG provide robust monitoring capabilities which allow users to track both data points and the critical security component of certificate validity. The MQTT sensors monitor IoT devices and broker statistics to maintain the health of your messaging infrastructure.
As one system integrator put it: PRTG helped us consolidate our monitoring because we previously had to use three separate tools for our protocols. Our factory floor now communicates through one single monitoring tool that understands all required protocols. PRTG functions as an industrial systems universal translator that speaks all protocol languages.
Challenge 3: Network segmentation & air gaps
Operational and security requirements lead many OT networks to separate themselves from IT networks through segmentation or complete air-gapping practices. This security measure produces complex monitoring challenges. What methods enable monitoring of these intentionally separated environments without breaching their isolation?
The PRTG solution: The design of PRTG's distributed architecture alongside remote probes makes it an ideal solution for environments with segmented networks. The deployment of probes within secure OT zones enables local data collection which they then send securely to the central PRTG server.
The multi-platform probe from PRTG operates on several operating systems which consist of resource-constrained embedded Linux systems used in industrial applications for high-security environments. The system's flexibility allows you to position monitoring functions at precise locations despite the network structure or security needs.
The pharmaceutical company adopted this method for cleanroom environment monitoring to stay compliant with FDA 21 CFR Part 11 and GxP standards. The remote probes tracked essential cleanroom parameters such as differential pressure and temperature while ensuring validated systems remained separated from the corporate IT network.
Challenge 4: Multi-vendor environments
The standard OT environment exhibits technological layers that represent historical advancements from various industrial periods. Your operational technology environment might include Siemens PLCs and ABB HMIs as well as Schneider RTUs and custom solutions from vendors that went out of business. Different management tools accompany each component which results in a monitoring system that cannot be unified.
The PRTG solution: PRTG delivers vendor-independent monitoring solutions that integrate more than 250 native sensor types with broad customization features to unite system diversity. PRTG is capable of monitoring standard IT equipment as well as specialized industrial hardware together with custom solutions.
Custom sensor features deliver exceptional benefits in Operational Technology environments. Python-based custom sensors enable you to create monitoring systems for even the most obscure and specialized equipment. An industrial client leveraged this feature to monitor their proprietary control system which lacked commercial monitoring options by integrating it into their centralized monitoring system for the first time.
Our complete environment required eight separate dashboards before we consolidated them according to an automation engineer. Our PRTG dashboard now displays all network switch data alongside our specialized production equipment information.
Challenge 5: SCADA integration without disruption
Since your SCADA system manages your operations' critical functions you must approach any system changes with appropriate caution. It is essential to share monitoring data between your SCADA system and your broader monitoring setup while maintaining operational stability.
The PRTG solution: OPC UA Server in PRTG provides seamless data integration capabilities with SCADA and HMI systems without causing disruptions. The PRTG OPC UA server extension provides monitoring data access to any OPC UA client such as SCADA systems and DCSs along with HMIs and PLCs.
Through bidirectional communication your SCADA system can receive monitoring data from PRTG including network performance metrics while PRTG integrates operational data from your SCADA system into its monitoring and alerting workflows.
The food processing plant utilized this capability to link production line speeds with network performance metrics which helped identify hidden bottlenecks that impacted throughput levels. Standard OPC UA integration meant the SCADA system needed no modifications.
Real-world success: Pharmaceutical cleanroom monitoring
We will examine how these solutions function together within a practical application. A pharmaceutical company required HVAC systems, temperature, and pressure monitoring in GMP cleanrooms to meet FDA regulations and GxP standards.
The environment presented multiple challenges:
- Legacy building management systems with Modbus interfaces
- The production and corporate networks maintained strict separation to protect sensitive information.
- The system needs to meet strict requirements for data integrity and comprehensive audit trails.
- Multiple vendor systems that needed centralized monitoring
They resolved all the challenges by implementing a PRTG-based solution:
- The building management system operated under the surveillance of Modbus TCP sensors.
- The segmented production network received remote probe deployment.
- Data was securely aggregated for compliance reporting
- The custom dashboards enabled operations and quality assurance teams to monitor their activities.
The result? The system's automated alerts allowed for continuous monitoring and prevented potential compliance issues from developing. The system returned its investment cost in less than a year after stopping a single temperature deviation that would have destroyed valuable product.
FAQ: The not-so-standard questions about OT monitoring
Is PRTG capable of supporting regulatory compliance needs within environments that require validation?
Absolutely! PRTG proves highly beneficial for regulated sectors such as pharmaceuticals and food production. Through advanced logging and alert mechanisms combined with detailed reporting functions PRTG retains compliance with FDA 21 CFR Part 11 alongside GxP and ISO standards. Operational continuity is sustained through tamper-evident audit trails and automated excursion alerts while detailed reporting functions for regulatory inspections.
One pharmaceutical customer even commented: The auditing team expressed their satisfaction with the comprehensive monitoring data we delivered. The inspection reporting process that took days to finish now requires only minutes with PRTG's reporting system.
What mechanisms does PRTG implement to manage sporadic network connections in remote OT sites?
Industries such as utilities and oil & gas face regular connectivity problems at remote sites. PRTG's built-in architecture maintains performance stability during remote site connection failures. Remote probes store monitoring data locally during connection disruptions and upload it once connectivity returns to prevent data loss.
PRTG provides connectivity monitoring that alerts you to communication disruptions while assisting in identifying whether problems are due to equipment faults or just communication failures. Customers operating remote assets in difficult environments have found this feature to be extremely beneficial.
Is it possible for PRTG to function as a replacement for specialized OT security monitoring tools?
PRTG serves as a supplementary tool to specialized security solutions through its ability to provide visibility which improves overall security monitoring. PRTG identifies irregular device patterns and communication irregularities together with unexpected operational parameter changes which signify potential security threats.
Customers operate PRTG together with specialized OT security tools because PRTG delivers broad visibility while security tools supply deeper inspection capabilities. By combining both solutions a more complete security posture emerges beyond what each can achieve independently.
The bottom line
Managing OT monitoring systems can be straightforward with the proper tools. PRTG enables users to manage industrial monitoring difficulties while streamlining their monitoring tools and lowering expenses. PRTG delivers a single solution that simplifies the complexity of OT monitoring across both legacy equipment and multi-vendor systems, segmented networks and regulatory compliance requirements.
Want to find out how PRTG revolutionizes your Operational Technology monitoring? Request your free consultation today to understand why thousands of companies rely on PRTG for their essential industrial system monitoring needs.
And of course you are welcome to test PRTG Network Monitor free for 30 days and experience a hassle-free monitoring experience.
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