Many persistent production issues can be traced back to the operational technology (OT) network. An information technology/operational technology (IT/OT) assessment helps manufacturers evaluate the current state of their network, find and resolve common communication faults and strategically plan upgrades that support digitalization, cybersecurity and compliance with industry requirements. By aligning network design with regulatory expectations organizations can reduce operational risk and ensure long-term resilience.
Secure and robust OT networks have become essential infrastructure for industrial manufacturing over the past decade. They are the backbone of a facility, ensuring the reliable communication on which operations depend.
OT networks connect the shop floor to business systems, cloud platforms, remote support tools and other digitalization initiatives that increase operations visibility, real-time decision-making and control.
But most manufacturers can’t answer the basic question: “What’s connected to your OT network and how?”
Many manufacturers continue to rely on outdated, undocumented, ad hoc network infrastructures that weren’t designed to handle today’s connectivity, performance or cybersecurity needs. Their weak OT networks not only hold back digital transformation initiatives, but also unknowingly cause perplexing production issues and looming cybersecurity risks.
Industrial networking challenges can be addressed systematically, beginning with an evaluation of the state of the network itself. Known as an IT/OT network assessment, it is a frequently overlooked, relatively low-cost tool that can help manufacturers improve the state of their operations.
The assessment uncovers clear, detailed information about the existing OT network while identifying and evaluating all connected devices. It often readily finds the root causes of various intermittent production problems that result in reliability and performance issues and unexplained downtime. Furthermore, the assessment’s findings can be used to form a prioritized roadmap for upgrading both infrastructure and assets.
While devising a robust cybersecurity posture is a key outcome of an IT/OT assessment, this article focuses more on its effectiveness for finding and fixing common production problems related to OT network shortfalls.
Most manufacturers do not understand their OT network
Unlike IT networks which tend to be managed and periodically upgraded, OT networks are often pieced together as needs have arisen over time with minimal documentation or long-term planning.
Most manufacturers operate without important foundational knowledge about the network that connects their critical infrastructure. They typically do not have:
- A complete asset list with operating firmware versions
- A drawing of their OT network
- An understanding of their network layout or topology
- Documentation of all IP addresses in current use
- An effective cybersecurity posture
This lack of information makes it very difficult for manufacturers to diagnose and fix various communication-based production problems. In fact, it’s common that they don’t realize that the root cause of many intermittent issues traces back to an OT network weakness.
Four production problems that trace back to the OT network
These are the four common production problems and the underlying OT network issues that are often their cause.
- Intermittent line stoppage
- Random slow-downs and pauses
- Single-device failure which stops the line
- WiFi dead zones on the shop floor
Because an IT/OT assessment evaluates a facility from the perspective of the OT network, it is highly effective at finding the underlying infrastructure problems causing these shop-floor issues.
Problem 1: Intermittent line stoppage
Common causes:
- Improper cabling and connectors
- IP address conflicts
- Misconfigured Switches
This problem typically appears as sudden, unexpected halts to production, equipment faults or frozen HMI screens. It is often resolved by restarting a device but continues to return intermittently. Some of the most common reasons for this behavior are discussed below.
1.1 Unshielded, office-grade Ethernet cabling reduces signal integrity
Many plants unknowingly use office-grade, unshielded Ethernet cables in high-voltage industrial cabinets, in conflict with NEC standard 800.133 (A)(2) which requires communication cables to be separated from power conductors or installed with physical barriers in industrial enclosures.
Without adequate shielding for the industrial environment, signal integrity is often compromised by external electromagnetic interference from nearby high-voltage industrial equipment including motor drives or transformers.
Office-grade cabling, which typically lacks shielding, is also more susceptible to crosstalk between wires within the same cable. Shielding is particularly important within industrial settings, due to longer cable runs, high network load, tighter cable bundles and harsher installation conditions. The resulting signal disruption causes intermittent communication errors that disrupt production.
In addition to performance concerns, using non-industrial cabling in harsh environments can present safety risks. Office-grade cables are not designed for proximity to high-voltage conductors like standard industrial 480V power lines as they lack sufficient insulation and voltage isolation. Over time, the insulation on these cables can degrade due to harsh industrial environment conditions.
As a worst-case fault scenario, should a damaged cable encounter a high-voltage source, it may become energized. Because Ethernet cables are intended to carry only low-voltage data signals, workers may not expect this hazard. Adhering to NEC-compliant routing practices and using industrial-rated cabling helps ensure personnel safety and operational reliability.
1.2 Office-grade crimped connectors fail in industrial environments
In many industrial settings, crimped RJ-45 connectors, commonly used in office environments, are installed on the ends of OT network Ethernet cables. Their use persists despite the ANSI/TIA-1005-A standard that recommends rugged connectors including the M12 for use in high-vibration environments.
Often found in control panels and even on moving machinery, crimped connectors are not designed to withstand consistent vibration or flexing which causes them to loosen over time and intermittently lose contact. These momentary connection failures interrupt data transmission, resulting in slowed or stopped communication or even complete device disconnection.
Connector comparison: RJ-45 crimped versus M12
| Feature | RJ-45 (Crimped) | M12 (Ruggedized) |
| Typical Use | Office networks, light-duty panels | Industrial automation, harsh zones |
| Vibration Resistance | Poor | Excellent |
| Ingress Protection | Low (IP20) | High (IP67 or better) |
| Coupling Method | Friction-fit clip | Threaded, locking design |
| Installation Environment | Low-noise, climate-controlled | High EMI, dust, moisture, vibration |
| Standards Reference | ANSI/TIA-568 | ANSI/TIA-1005-A |
1.3 Duplicate IP addresses drop devices
An IP address is a device’s unique identifier that allows it to communicate with other connected devices. When a facility lacks documentation of IP addresses currently in use, it’s easy for a second device to be unintentionally assigned an address that is already taken.
Duplication can happen with a newly added component, a test laptop or even an infrequently used machine but does not cause problems until both devices seek a network connection. When this occurs, they compete for the same address which disrupts communication for one or both devices. This often results in lost control signals and dropped data packets, which in turn cause intermittent equipment faults and lead to devices unexpectedly going offline.
1.4 Misconfigured switches disrupt communication
IT/OT assessments frequently reveal misconfigured switches that do not align with the actual needs of the production environment. In many cases, adjusting these settings is enough to eliminate recurring communication faults without replacing any hardware.
Section 2.3 elaborates on how switch type, construction and configuration impact network performance and system reliability in industrial environments.
Problem 2: Random slow-downs and pauses
Common causes:
- Poor network design
- Misconfigured device drivers
- Unmanaged switches
This issue is one of the most frequent and confounding problems seen in manufacturing facilities. It presents in a variety of ways and often gets worse over time:
- Slow human-machine interface (HMI) screen refresh-rate
- Programmable logic controllers (PLCs) occasionally drop communication with their remote I/O
- Robots pause or perform erratically
- Alarms are delayed or appear out of sequence
The heart of the problem is once again related to the OT network as discussed below.
2.1 Flat IT-OT networks don’t support traffic prioritization
Many facilities operate their industrial equipment directly on their office IT network, commonly termed a flat network configuration. Communication traffic from all sources travels together, creating congestion and unpredictable latency. Meanwhile, some industrial equipment, including robotics and computer numerical control (CNC) machines, demands a reliable, time-sensitive connection to the controls system. This requirement cannot be accommodated on a traditional IT network, resulting in poor performance of these systems.
Flat network architectures also introduce significant cybersecurity risks.
According to Dragos’s 2023 OT Cybersecurity Threat Landscape, nearly one-third of assessed industrial sites had segmentation issues or misconfigured firewalls, resulting in flat or poorly protected OT networks. The ISA/IEC 62443-3-3 standard mandates network segmentation and boundary protections that apply to the IT/OT network interface and various zones within the OT network.
Without network separation, any compromise of the business network can provide an attacker with direct access to critical production systems. The risk is even greater for facilities running older equipment that lacks modern security features.
2.2 Misconfigured drivers saturate the PLC and the network
Sometimes the software settings that control how devices communicate over the OT network are not properly tuned to its capabilities or bandwidth. A device’s drivers determine the frequency and the quantity of data that is requested and pulled from a controller or other networked device. When misconfigured to request either too much data or to make requests too frequently, it can overload controllers, congest the network and degrade system performance. The result is delayed screen updates, slow alarms or intermittent communication failures.
In one case, E Tech Group was called in to address a problem of HMI screen-freezing that seemed to correlate with production line issues. This problem had perplexed previous integrators as well as the HMI and PLC OEM technicians.
By assessing the amount of traffic on the network using standard scanning tools, E Tech Group was quickly able to determine that the HMI’s driver was polling the PLC too frequently, overloading it and causing intermittent issues on the line. The problem was fully resolved by adjusting the HMI’s polling settings accordingly.
2.3 Switches that can’t handle industrial traffic
During an assessment, physical inspections often uncover unmanaged, frequently consumer-grade network switches installed within industrial control panels. On an OT network, it is essential to monitor and manage traffic flow, isolate faults and ensure communication paths remain stable during abnormal conditions. These capabilities require use of correctly configured industrial-grade managed switches.
In contrast, unmanaged switches lack the necessary features to support visibility, control and reliability that are specific needs of the OT environment.Without these features, the network may experience latency or packet loss, leading to unpredictable system behavior and an inability to reliably support advanced automation systems that depend on deterministic performance for precise motion control including robotics, vision systems and CNC applications.
Additionally, unmanaged switches do not support many of the industrial communication protocols required by shop-floor equipment, including Ethernet/IP and PROFINET, which can lead to intermittent or total loss of communication between system components and result in overall operational instability.
Finally, consumer-grade switches (i.e. NetGear, LinkSys brands) lack the shielding and rugged construction needed for industrial environments, making them vulnerable to eventual failure from electrical noise, temperature fluctuations and vibration.
Managed switches provide tools to control how data flows through the network. They allow users to assign specific functions to each connection point, prioritize critical traffic and segment the network into zones to prevent one issue from affecting the whole system. This level of control makes it easier to detect and troubleshoot problems, helping maintain uptime and meet the performance demands of industrial automation.
Problem 3: Single device failure stops the line
Common cause:
- A network structure that lacks path redundancy
3.1 Daisy-chained (linear) topologies lack redundancy
In many manufacturing environments, devices are connected in a linear arrangement that is commonly called “daisy chained.” While simple to implement, it lacks the path redundancy required for reliable performance. When one device is brought down, all downstream devices lose their connection, often disconnecting the entire line.
[subhead/h2] Fixing PLC latency and communication errors
E Tech Group was called in to fix a particular PLC’s problematic latency and intermittent communication errors. Upon completion of the network assessment, the topology map showed that the entire facility was wired in a single daisy-chain, and the problematic PLC was positioned at the far end of it. Every data packet it sent had to pass through each upstream device before reaching the plant’s central switch, resulting in cumulative delays and frequent packet loss.
To resolve the issue, E Tech Group installed two additional cable paths to introduce network redundancy near the midpoint of the chain. While the overall topology remained primarily linear, the new paths provided alternate routes for traffic, reducing the impact of congestion. A managed switch was deployed to support the new connections and ensure proper traffic handling. All work was completed within a brief maintenance window and once the redundant paths were brought online, latency and connection drops were eliminated, resulting in stable and reliable line operation
Problem 4: Wi-fi dead zones on the shop floor
Common causes:
- Equipment noise interference
- Unapproved access point interference
Common Wi-Fi network issues uncovered during an IT/OT assessment include inadequate coverage, interference and unapproved (rogue) access points. All three issues result in connectivity problems and reduced communication in certain areas of the plant. The latter also poses a significant security risk.
4.1 Noise from poorly tuned drives causes wi-fi interference
Some industrial equipment, particularly motor drives, can emit high-frequency electromagnetic noise when poorly tuned or improperly installed. Some of this noise can overlap with wi-fi operating frequency bands, leading to signal interference, dropped connections and degraded wireless performance in their vicinity.
Interestingly, E Tech Group has found that an unexpected source of Wi-Fi interference is older or low-quality break room microwave ovens, which often do not include enough shielding in the Wi-Fi frequency range to prevent interference.
4.2 Rogue access points cause wi-fi interference
Assessments often find unauthorized wireless access points that may have been installed by OEMs, contractors or even plant personnel. These devices introduce wireless conflicts with the facility’s WiFi network, degrading its performance.
Perhaps more importantly, it’s common for OEMs to install these access points directly within their equipment’s control panels so that they have easy remote support accessibility. Unfortunately, it’s also common that these devices’ login IDs and passwords are not changed from their publicly available default settings, leaving a wide open, unmonitored entry point directly onto the OT network. Any rogue access point bypasses existing cybersecurity safeguards, dramatically increasing cybersecurity risks.
From network visibility to a strategic upgrade plan
Beyond revealing the underlying causes of common production floor problems, the information gathered from a typical IT/OT network assessment is particularly suitable for long-range upgrades planning.
Consider the following:
- Network scanning tools identify all connected assets along with their current operating firmware versions. Many of these tools cross-reference this data with vulnerability databases that catalogue known cybersecurity risks associated with specific firmware. This information allows a manufacturer to prioritize firmware upgrades by their relative risk.
- Network scanning tools also devise a network topology map, showing how devices are connected and how data flows across the network. This visibility guides strategic decisions including where to add redundant communication paths, isolate (segment) traffic into zones for improved performance and security or upgrade hardware to strengthen overall network reliability.
- Findings from the physical inspection highlight immediate safety and connectivity concerns that may be contributing to performance issues and unexpected downtime. This information informs a manufacturer of all required urgent repairs, code compliance issues and needed hardware replacements.
Together, these insights can be assembled and ordered with respect to their relative priority and urgency so that manufacturers know in what order to approach them.
Build a secure, future-ready infrastructure
The portfolio of new digital manufacturing tools continues to expand, each offering new ways of increasing manufacturing productivity. Because they all rely on robust network connectivity, those who invest in their OT network’s infrastructure are best positioned to adopt and benefit from the competitive advantages these novel tools bring.
An IT/OT network assessment gives manufacturers the valuable insights they need to upgrade the state of their facility. These insights often readily find the root causes of recurring production issues including intermittent line stoppages, slow HMI updates and unexpected device disconnects. The resulting prioritized, data-driven roadmap simplifies the decision-making process so that gains in system reliability, performance and security are approached in a strategic manner. An assessment lays the foundation on which manufacturers can plan and then achieve their digitalization goals.
What is an IT/OT Assessment?
Used to identify connected assets, communication paths and weaknesses in the OT network
An IT/OT assessment is a structured evaluation of an industrial facility’s operational technology (OT) network. It identifies device-level issues, communication gaps and hidden infrastructure vulnerabilities that can impact production performance and system reliability.
The assessment process typically includes a:
- Detailed network scan that detects all active devices, including their firmware versions, IP addresses and communication paths
- Network topology map that lays out every device’s connection point onto the network and all paths of communication
- Physical inspection of control panels, cabling and wireless coverage to assess installation quality, code compliance and hardware condition
- Review of WiFi coverage
- Review of security configurations, often aligned with ISA/IEC 62443-3-2 guidance for system design risk assessment
Eric Medecke is the director of IT/OT solutions and Kevin Romer, CCNA is the principal engineer and solutions architect with E Tech Group.
