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13-12-2019
5 min. read
Sjors de Kleijn
Last update: 26-05-2021

How to troubleshoot PLC problems remotely?

Why remote troubleshooting is needed, the benefits and an easy solution to get remote access to PLC controllers

Programmable Logic Controllers (PLC) are part of the basic infrastructure of industrial automation implementations and are used to control processes or individual industrial machines. When PLC problems occur or changes are needed to the program, remote troubleshooting and accessing remotely can lead to more flexibility and cost savings.

In this article we’ll explain the needs and benefits of remote access and how this can help to remotely troubleshoot PLCs problems.

PLC and VPN connectivity device for remote troubleshooting PLC and VPN connectivity device for remote troubleshooting

The need of remote troubleshooting PLCs

Industrial machinery and equipment are built to last for a long period of time. After installation and commissioning and during the operation several breakdown problems can occur or changes to the PLC program can be needed to optimise and troubleshoot the PLC. 

Let’s take a look at the different needs for remote PLC control.

Investigating causes of PLC problems

There are several PLC problems that can cause errors. Common PLC problems are communication errors, input/output module failures and power outage. A communication error can occur between the programmable computer and the devices it controls.

To investigate the potential PLC problem the use of PLC remote access helps to solve issues from any remote location. It provides a simple and secure method of connecting to a PLC controller which gives you full access and the ability to run for example a PLC scan.

Remote access to PLCs, and connected phericals, are great solutions for establishing remote support from any network-connected location. Managing a PLC with remote access can lead to quick configurations and deliver remote support to your industrial equipment.

Benefits of remote working in industrial automation Benefits of remote working in industrial automation

PLC program changes

PLC programs are never final and due to changing customer requirements you will always need to make corrections and adaptations to the system. Even during operation, program changes are often necessary as the PLC program can almost always be improved after the first test run for optimisation. 

All available offline and virtual PLC program testing tools can be used intensively to test program faults and run simulations. Corrections and modifications to the PLC program, transferring and testing of software can nowadays be easily done remotely to save valuable hours for the (service) engineer.

Remote commissioning of the entire system

PLC commissioning is a series of careful examinations done in a PLC control system to ensure that the controller, program, input and output devices conform to the specifications of the design. Once the final status of the PLC program is established, tested and the entire system commissioned, the system is ready to be handed over to the customer.

With the help of a local engineer or operator, remote commissioning can save on travelling expenses. Augmented reality solutions can support remote assistance.

The benefits of remote PLC troubleshooting

Remote troubleshooting and maintenance of PLCs will lead to a better performance for service teams and engineers. By working remotely you can maintain and troubleshoot your machines around the world, which can lead up to 90% solved machine issues. This provides expert level services from remote locations that dramatically reduce maintenance costs and increase first time fixed and machine uptime

The first step is to get your PLC connected securely to the internet by installing an industrial remote access router near your PLC.

Illustration of IXON Cloud setup and steps to access a PLC securely over the internet Illustration of IXON Cloud setup and steps to access a PLC securely over the internet

How to access PLCs remotely

In order to access PLCs remotely and start remote PLC troubleshooting, you need to connect your PLC to the internet. 

Following these simple steps connects your PLC to the internet and helps you troubleshoot your PLC from remote using the IXrouter and IXON Cloud platform:

  • Connect your PLC to the IXrouter (combined industrial VPN router and edge gateway). If your PLC doesn’t have an ethernet port, you can try a RS-232 / RS-485 to ethernet converter or IBH Link S7++ for older Siemens hardware.
  • Configure the internet connection for the IXrouter to connect it to the internet and IXON Cloud platform so you can set up a secure VPN connection to the PLC. Depending on the IXrouter model, it can set up an internet connection over Ethernet, Wi-Fi and/or 4G/LTE. If the PLC is located in an isolated location with poor or missing internet connectivity, or if you cannot use the factory internet connection, you can use a model with 4G/LTE internet connectivity. 
  • Establish the client connecting from your remote computer, through the IXON Cloud platform, to the PLC. This gives you secure network access through a VPN tunnel.
  • Now that you can get to the PLC from your workstation, you can troubleshoot the PLC and solve the problem.

What can you do to troubleshoot your PLC and phericals from remote?

Using the IXON Cloud platform, you have full remote control to troubleshoot all your industrial equipment. With a remote VPN connection to the PLC you have full access and control over the PLC (and connected devices) for a status check or to access log files.  

Additionally, you can easily connect to HMI panels and take over the control panels using VNC to adjust settings or access local HTTP web servers to view industrial robots programs. For more detailed monitoring you can transmit PLC data, log in securely in the cloud and create machine dashboards. Those tools combined will help you find and solve PLC problems.

Download and upload PLC programs over the internet

To access your PLC program remotely you start a VPN connection. It’s just like connecting the PLC directly to your PC. Now you can upload your PLC program remotely and deploy (upload or download) new software via the provided software tools (e.g. TIA portal) to the PLC.

Siemens TIA portal - accessible for remote troubleshooting PLC Siemens TIA portal - accessible for remote troubleshooting PLC

How to access PLC data remotely

Live and historical data can help to analyse PLC problems and recognise patterns before failure. It gives insights into how the machine is performing and how long it’s going to work. To get access to your PLC data from remote, you can use the Data Logging facility of IXON Cloud. This is a robust, secure and reliable way to send data to the cloud directly from the PLC. 

The data and parameters from your PLC are locally collected by the IXrouter via industrial protocols like OPC-UA, Modbus, Ethernet-IP. The data will be securely transmitted and stored in the IXON Cloud databases for raw export (CSV), data visualisation or for use in external applications via the API

It is very easy to set up data collection, which doesn’t require programming. Just follow these steps to access PLC data remotely:

  1. First set up a data source in the IXON Cloud via one of the compatible industrial protocols.
  2. Next, configure the PLC variables you want to log and store.
  3. Finally, configure log triggers to define when the data should be transferred and stored.


The IXrouter or embedded software agent (‘IXagent’) handles your configuration carefully thanks to the built-in edge technology. It “talks'' to the PLC to monitor, collect, prepare and transmit the PLC data according to your settings.

Industrial protocols to access PLC data remotely Industrial protocols to access PLC data remotely

Security measures; prevent unwanted access to your PLC

According to a PLC access control security analysis, PLCs are a preferred target for industrial control system (ICS) attackers. Therefore IXON provides several security measures to protect the machine builder and their customers with a secure Industrial IoT solution so they can troubleshoot PLC problems remotely without having to worry about security issues.

Using the advanced role-based user system you are in control of each user's access rights. The IXrouter’s built-in firewall blocks unwanted access to the PLC from outside the plant and separates the machine network from the corporate network. IXON's Certificate Authority system prevents Man-in-the-Middle attacks and eliminates the need for a fixed IP address or opening up firewall ports. 

All security measures are documented in our security whitepaper. This helps you understand how the solution is secured and what is and isn’t accessible.

Secure remote troubleshooting of PLC using IXON Cloud Secure remote troubleshooting of PLC using IXON Cloud

Easy troubleshooting PLCs using IXON’s remote service solution

Troubleshooting PLCs remotely will bring you flexibility in the way you service customers’ machines. A secure connection to your PLC helps you fix software issues in an easier stage and increases the uptime of your industrial equipment.

In the IXON Cloud you can easily manage your industrial devices, support your machinery remotely and visualise PLC data. In our product tour you can experience a demo setup and test the remote access and data functionality. 

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