IoT Gateway: Integration of PLC with IoT

Programmable Logical Controllers (PLCs) are present in almost all modern industries. Although they come in many shapes and forms, they have one goal: to control, measure, and carry out tasks in real-time within complex industrial applications. 

PLCs have played the role of robust and flexible brains for automation systems on factory floors for decades. They are, in fact, known as the edge computers within the OT world. But while PLCs evolve in specific industrial control processes, the Industrial IoT (IIoT) technology disrupts the entire industry.

Integrating PLC systems with an Industrial IoT architecture will introduce unprecedented value and benefits. But integrating PLCs to an IoT domain is no easy task, especially when PLCs have poor networking capabilities and lack interoperability. This is where the Industrial IoT gateway comes in handy, as it makes all PLCs ready for IoT. 

1.  PLC Challenges:

PLCs continuously monitor the state of input devices such as sensors, make decisions based on a custom program, and trigger an output to a control device, such as an actuator or alarm system. All this input makes PLCs concentrate a massive amount of operational data, which unfortunately ends up locked in within factories. Although most modern PLCs can communicate with one another or send information to a local dashboard using basic networking capabilities, they were not designed for remote communications. Considering a PLC with access to the Internet a few years ago would have seemed like an absurd idea.


Below are three of the most common challenges that PLCs present: 

a. Data Exchange.

PLC automation networks are usually closed-loops, where valuable and critical data ends up staying locked inside factory floors. These networks end up creating problematic data silos. The poor networking connectivity causes legacy PLCs to have limited data exchange with high-end systems. Although modern PLCs have connectivity capabilities such as Ethernet for data exchange, deploying wired infrastructure in complex and harsh industrial environments can be challenging.

b. Interoperability.

Most PLC models, especially the old ones, utilize proprietary data exchange or vendor-specific protocols that complicate interoperability. Certain SCADA and ICS systems are also vendor-specific and only operable with PLCs from the same vendor. Such a lack of interoperability can make PLC integrations with systems like SCADA, ICS, or IT systems challenging.

c. Lack of data insights.

Over time, PLCs accumulate minor inconsistencies such as I/Omodule errors or may also suffer from power outages that could indirectly compromise entire control systems. To avoid such PLC issues, factory engineers need to constantly and carefully inspect the machinery. Unfortunately, PLCs lack systems that monitor and predict the problems from the machinery.

2. Integrating PLC with IIoT with Industrial IoT gateway.

An Industrial IoT (IIoT) Gateway integrates all PLCs and makes them ready for the connected industry. An IIoT gateway can bridge the gap between OT and IT, allowing the integration of PLCs to the IT, SCADA, or ICS network.


An IIoT gateway provides an interface to the brownfield PLCs. It allows easier data collection, Internet connection, access to cloud-based applications, storage, and more. As shown in the diagram above, the sensors collect data (for example, PLC tags) from the brownfield PLC and forward it to the IoT gateway. The IoT gateway transfers the data reliably and securely to a cloud platform or an on-premises management or monitoring system. The data collected can be used for machinery status tracking, asset utilization, fault detection, machine performance, and per-unite maintenance costs.


In addition, PLCs are designed to operate in harsh environments. So, any IT-related equipment working under the same conditions also needs to be rugged. As opposed to commercial IoT gateways, an Industrial IoT gateway is rugged, so it is capable of withstanding harsh environments, while at the same time providing connectivity, security, and data processing.

a. The Next-generation Industrial IoT gateway.

Lanner’s ISD-O370 is a next-generation rugged industrial IoT gateway. It comes with outstanding wireless support, ruggedness certifications, rich I/O, and Power-over-Ethernet (PoE) ports for power efficiency. The ISD-O370 rugged industrial IoT gateway is optimized for industrial IoT. It can be integrated directly with the PLCs or through the supervisory control systems.

The ISD-O370 features industrial-grade connectivity (wired and wireless) in a rugged form factor. It provides the following features:

ISD-O370 Feature Highlights.

  • IP67-compliant 5G and Wi-Fi 6 wireless. Dust and waterproof chassis and antennas for both 5G and Wi-Fi6 with optimized signal reception.
  • Extension for wireless and storage. Extension for 5G and Wi-Fi 6 wireless capabilities via M.2 sockets, one M.2 2242 socket for storage, or onboard eMMC 64GB.
  • Optimized Ethernet ports. All Ethernet ports are supported with SR-IOV virtualization acceleration. Ports include four GbE LANs and two GbE PoE+ for Ethernet and powered devices connectivity.
  • Isolated I/O with 1.5KV. One serial RS232/485 by M12 X-coded 8pin Female connector with isolation 1.5KVAC/2.1KVDC, and one USB 3.0 by M12 A-coded 8pin Male connector.
  • Security and boot guard. ISD-I370 is protected with a secure boot/boot guard and TPM 2.0 security features.


The Benefits of Integrating PLC with an IIoT Gateway

The rugged IIoT gateway provides vital components for a comprehensive PLC integration solution. First, it delivers a high degree of robustness for operating under the harsh industrial domain. Without ruggedized features, any traditional IT appliance wouldn’t last long. Second, the available next-generation wireless connectivity capabilities, including 5G and WiFi-6, can support long-range and high-speed data transmissions. PLCs are deployed in remote, harsh, and complex industrial environments, so they need robust and high-speed wireless connectivity.

Third, An IIoT gateway with multiple I/O allows more compatibility with PLCs, supervisory control systems, and physical interfaces. And fourth and most important, the IIoT gateway bridges the gap between OT and IT. The IoT gateway can help integrate IoT with legacy and modern PLCs and collect critical data in real-time.

The IoT gateway features provide the following benefits.

  • Bring more intelligence to OT and unlock insights. The ISD-O370 is an edge network appliance, bringing more computational power to the industrial floor. With edge computing capabilities, the OT domain can be empowered with data-driven production decisions and unlock real-time insights.
  • Predictive maintenance and problem resolution. The real-time and historical data feeds allow personnel (through additional software) to identify and solve issues before they happen and interrupt production processes. Predictive maintenance through Machine Learning will help reduce maintenance costs and avoid major failures.
  • Introduce security to the ICS/OT domain. A rugged industrial IoT gateway with firewall capabilities is also the right appliance to secure sensitive industrial domains. Protecting the communications between IT and OT is critical.

Equipment and machinery monitoring. The IIoT gateway with additional software or server can forward data to monitoring systems that keep track of machinery and send alerts when they detect anomalies.

Final words

In this blog post, we went through PLCs’ common challenges. First, they have difficulties exchanging data; second, operating with each other is not easy; third, PLCs are usually incapable of providing data insights. A solution that helps solve such challenges is integrating PLCs with IIoT technology using an Industrial IoT gateway. A next-generation IIoT gateway such as Lanner’s ISO-O370 is capable of bridging the gap between IT and OT. The industrial IIoT gateway can operate under harsh industrial environments. In addition, it also provides outstanding wireless capabilities to facilitate communications in such environments.

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