Component Object Model (COM)

In industrial communication, the evolution towards a standardized framework has been driven by the pressing need to address interoperability, modularity, and scalability challenges that have long plagued systems reliant on proprietary protocols and custom software solutions. Historically, these traditional systems were often ensnared in a web of incompatibility issues, severely limiting their flexibility and scalability. This scenario underscored the critical necessity for a paradigm shift towards open standards and interoperability to foster seamless communication and integration across diverse systems and devices.

The Component Object Model (COM) played a pivotal role in addressing these challenges. Introduced by Microsoft in 1993, COM is a binary-interface standard for software components that facilitates inter-process communication (IPC) and object creation across a wide range of programming languages. This innovation not only streamlined software development but also laid the groundwork for subsequent advancements in industrial automation. The industrial automation sector recognized the potential of Component Object Model in the mid-1990s for fostering interoperability and modular design, prompting vendors to integrate COM-based technologies into their offerings. This integration underscored Component Object Model versatility as a platform-independent and language-neutral framework, enabling seamless interaction between industrial devices and systems.

The mid-1990s witnessed the advent of OLE for Process Control (OPC), a set of COM-based standards specifically tailored for industrial automation and process control systems. OPC emerged as a critical enabler of interoperability, allowing for the smooth integration and communication of industrial devices with software applications. Beyond OPC, the adoption of Component Object Model -based middleware solutions also become increasingly prevalent in industrial communication. These solutions leverage Component Object Models interoperability capabilities to facilitate data exchange and integration among industrial devices and systems, further emphasizing COM's integral role in the sector. Despite the emergence of new standards and technologies, Component Object Models continues to be a vital component of industrial communication. Many legacy systems and applications rely on Component Object Models-based technologies, underscoring its ongoing significance in ensuring interoperability and modularity within industrial automation.

The essence of COM lies in its ability to provide a language-neutral way of implementing objects that can be utilized in environments different from where they were created, including across machine boundaries. This feature is particularly beneficial in industrial settings where machinery and devices from various manufacturers need to communicate seamlessly. The architecture of COM allows for the reuse of objects without requiring knowledge of their internal implementation, thanks to well-defined interfaces separated from the implementation. Such a design principle ensures that components can interact in a flexible and scalable manner, overcoming the limitations posed by incompatibility among different systems.

Moreover, COM supports distributed computing through Distributed Component Object Model (DCOM), which extends the functionality of COM to support applications communicating across network boundaries. This extension is crucial for industrial communication as it enables devices and systems to interact over a network, facilitating remote monitoring and control of industrial processes. DCOM introduction of features for configuring user authority and specifying encryption for call security further enhances the robustness of industrial communication networks. In addition to DCOM, COM+ was introduced as a significant extension, providing support for distributed transactions, resource pooling, and event publication and subscription among other services. These features are vital for managing complex industrial operations that require high levels of reliability and efficiency. COM+ improves upon Component Object Model by offering better memory and processor management, thereby enhancing the performance and scalability of industrial communication systems.

At the heart of COM architecture are Interfaces, Objects, Components, the COM Runtime Environment, and Binary Compatibility, each playing a crucial role in facilitating seamless inter-process and cross-network communication.

COM Interfaces 

COM Interfaces serve as contracts between components, defining a set of related operations without dictating their implementation. Objects and Components form the building blocks of the Component Object Model. A COM object, or component, is an instance of a class that encapsulates both data and behaviour, exposing its functionality solely through interfaces. This encapsulation and strict interface adherence enable the creation of reusable, modular software components that can be easily integrated into larger systems, regardless of the programming language used for their development.

COM Runtime Environment

The COM Runtime Environment is a critical infrastructure component that supports the registration, creation, and management of COM objects. Lastly, Binary Compatibility is a cornerstone of Component Object Model (COM) design, enabling components to interact across process boundaries and even networked environments without requiring source code access or recompilation. This compatibility is achieved through a binary standard for function calls and a unique identification system for interfaces and classes, ensuring that components can be seamlessly replaced or updated without affecting dependent systems.

In client-server architectures, COM plays a crucial role by enabling communication between COM objects regardless of their location, whether they are in-process or out-of-process. This interaction is facilitated using Remote Procedure Call (RPC) protocol, ensuring efficient communication between client and server components. The versatility of COM extends to peer-to-peer networks as well, where it can be utilized to enable direct communication and resource sharing among peers without necessitating a centralized server.

Middleware-based architectures also benefit from the interoperability features of COM. Middleware acts as a bridge between disparate technologies, tools, and databases, facilitating their integration into a cohesive system. The ability of COM to enable seamless interaction between binary software components makes it an essential element in middleware solutions, ensuring smooth data flow and communication across different parts of a system.

Furthermore, Component Object Model influence extends to web-based architectures, where it supports the development of dynamic and interactive web applications. Through COM, developers can create reusable software components that can be deployed in web environments, contributing to the modular and scalable nature of web-based systems.

The Component Object Model (COM) significantly enhances industrial communication systems by offering a suite of advantages that cater to the diverse needs of modern industrial environments, as follow:

• Interoperability

  COM enables seamless integration of components written in different programming languages, ensuring compatibility across diverse platforms.

• Modularity

  COMs architecture allows for easy modification and updating of components without impacting the entire system, promoting code reusability, and simplifying software development.

• Scalability

  The Distributed Component Object Model facilitates the distribution of components across multiple computers, easing scaling efforts and reducing costs.

• Flexibility

  Component Object Models platform-independent nature allows for the creation of binary components that can interact across various operating systems and hardware platforms.

• Efficiency

  Standardized data transfer mechanisms, such as uniform data transfer, streamline the exchange of data between COM objects and processes, enhancing overall system efficiency.

• Security

  Component Object Model incorporates robust security features, including activation security and call security, to ensure secure creation and connection of COM objects.

• Standardization

  COMs adherence to industry standards fosters interoperability, security, and innovation, particularly relevant in industrial automation where device interoperability is critical.

• Legacy Integration

  The Component Object Model facilitates integration with existing systems, protecting investments in legacy infrastructure while enabling modernization efforts.

As a leading company in the field of industrial communication, Hilscher offers a broad portfolio of technologies and solutions for networking industrial environments.

This includes a wide range of interface solutions for connecting sensors, actuators and controllers to industrial communication networks. The communication controllers of the netX family form the basis for this. The multi-protocol-capable SoCs can be integrated into automation components as required and their extensive chip peripherals enable powerful, efficient and flexible solutions. A protocol change is achieved by simply reloading Hilscher's own netX firmware. Building on this, the company also offers embedded modules and PC cards in all form factors in order to realise the netX communication interface with less integration effort.

Hilscher also offers a comprehensive managed industrial IoT range under the netFIELD brand. This ranges from edge gateways as an application-oriented computer platform with integrated container management and the Edge OS Runtime running on it to the central cloud portal, via which the docker containers are deployed to the edge devices, through to turnkey containers for communication applications.

Gateways and switches, devices for network diagnostics as well as masters and bridges for the wireless connection of IO-Link sensors round off the automation portfolio.