ISA Interchange

Welcome to the official blog of the International Society of Automation (ISA).

This blog covers numerous topics on industrial automation such as operations & management, continuous & batch processing, connectivity, manufacturing & machine control, and Industry 4.0.

The material and information contained on this website is for general information purposes only. ISA blog posts may be authored by ISA staff and guest authors from the automation community. Views and opinions expressed by a guest author are solely their own, and do not necessarily represent those of ISA. Posts made by guest authors have been subject to peer review.

All Posts

How to Migrate ICS Networks to the Cloud #1: RTOS

We all use general-purpose operating systems (GPOS) such as Windows, Linux, and macOS in our daily lives and for work purposes. However, when it comes to mission-critical systems, we need additional capabilities that we do not have in GPOS. This is where we begin to hear the names of different operating systems, such as VxWorks, Microware, and OS-9. We call these operating systems real-time operating systems (RTOS).

RTOS are designed to handle time-sensitive operations and ensure that data is processed quickly and accurately. These operating systems are essential for many applications, including industrial control systems (ICS), avionics, and medical equipment, where it is crucial that data is processed and acted on in a timely manner. A RTOS allows for the coordination of multiple tasks and ensures that each task is completed within a specific timeframe. This allows for the smooth operation of systems that require quick and accurate processing of data.

A RTOS ensures real-time applications have a certain capability within a specified timeframe as well. RTOS is intended for critical systems and time-sensitive devices such as microcontrollers. The processing time required by a RTOS is measured in milliseconds, where any delay in responding could have disastrous results.

RTOS vs. GPOS

SS Table 1Due to the advantages of RTOS systems, the following industries prefer RTOS over GPOS:

  • Avionics
  • Command and control systems
  • Industrial automation
  • Medical devices
  • Automotive systems
  • Aerospace systems
  • Telecommunication systems

Azure RTOS and AWS FreeRTOS

Major vendors transfer the power of the cloud computing world to the ICS world through cloud internet of things (IoT) platforms. In this way, some levels in the familiar Purdue Model now work on the cloud. Of course, the greatest strength of the cloud is native applications and integration capabilities. In this context, cloud vendors who want to offer an end-to-end solution are also trying to get their hands on the RTOS world. There are several major cloud IoT platforms that include support for RTOS.

Azure IoT

Azure IoT is a cloud platform from Microsoft that includes support for RTOS. Azure RTOS is a RTOS that is available as part of the Azure IoT platform, and it can be used to develop real-time IoT applications that run on Azure IoT Edge devices. Azure RTOS is designed to be scalable, reliable, and secure, and it provides a complete RTOS that can be used to develop a wide range of IoT applications. Azure RTOS includes several key components, including:

  • ThreadX: A high-performance, real-time kernel that provides a multitasking environment for applications.
  • NetX: A network stack that supports various protocols, including TCP/IP, IPv6, and UDP.
  • FileX: A file system that allows applications to store and access data on various storage devices, including flash memory, SD cards, and external storage.
  • GUIX: A graphical user interface (GUI) framework that allows developers to create user-friendly interfaces for their applications.

Amazon Web Services (AWS) IoT

AWS IoT is a cloud platform from Amazon that includes support for RTOS. AWS FreeRTOS is a version of the open-source FreeRTOS that has been optimized to run on AWS, and it can be used to develop IoT applications that run on AWS IoT Core and AWS IoT Greengrass. AWS FreeRTOS is designed to support the development of IoT applications that require quick and reliable responses to events. AWS FreeRTOS is available as a free download from the AWS website. Similar to Azure IoT, AWS FreeRTOS is designed to be scalable, reliable, and secure, and it provides a complete RTOS that can be used to develop a wide range of IoT applications on AWS. In addition, like Azure IoT, AWS FreeRTOS includes several identical, key components, including:

  • A real-time kernel that provides a multitasking environment for applications.
  • A network stack that supports various protocols, including TCP/IP, IPv6, and UDP.
  • A file system that allows applications to store and access data on various storage devices, including flash memory, SD cards, and external storage.
  • A set of libraries and tools that make it easy to develop and deploy IoT applications on AWS.

In general, most major cloud IoT platforms include support for RTOS, allowing developers to create and deploy real-time IoT applications on the cloud. These platforms provide a range of tools and services, including RTOS, to help developers build, deploy, and manage their IoT applications.

Compliance to Standards

It is not common for cloud IoT platforms to be certified or compliant with the ISA/IEC 62443 series of standards for RTOS. The ISA/IEC 62443 series of standards are typically focused on the technical characteristics and performance of RTOS, rather than the platforms on which they run. However, some cloud IoT platforms may include RTOS that are certified or compliant with the ISA/IEC series of standards.

Azure RTOS is compliant with ISA/IEC 61508, a standard for functional safety of electrical/electronic/programmable electronic safety-related systems. ISA/IEC 61508 is a widely used standard that defines the requirements for functional safety in systems that use electrical, electronic, or programmable electronic technology. Compliance with this standard can provide assurance that a system is safe and reliable, and that it will function as intended in all conditions.

Azure RTOS is designed to support the development of real-time IoT applications that require quick and reliable responses to events. As such, it includes features that are designed to meet the requirements of ISA/IEC 61508, including support for error handling, error recovery, and other safety-related features. With Azure RTOS’ compliance with ISA/IEC 61508, one is assured that Azure RTOS is a safe and reliable operating system that can be used in safety-critical applications.


See Part 2 here.

Sedat Salman
Sedat Salman
Sedat Salman has a career of over 20 years in the field of cybersecurity, IT, OT, and cloud infrastructure, having worked as a Program Manager and Technical Leader/Manager. He is currently employed as a Digital Advisor and Global Solution Architect at Schneider Electric.

Related Posts

The Future of Automation in the Workforce—What Do We Need to Know?

The automation profession has always been in a state of constant evolution. In the early days, automation...
Steve Mustard May 30, 2023 3:50:56 PM

Five Benefits of Cloud Managed Services and Cloud Cost Monitoring

No matter the size of your business, IT leaders and CIOs increasingly recognize the benefits of leveragin...
Denise Kee May 26, 2023 3:03:05 PM

Automation Doesn’t Deserve its Bad Reputation

Automation gets a bad rap from many quarters. Politicians blame automation for the loss of manufacturing ...
Steve Mustard May 23, 2023 1:21:57 PM