Industrial Ethernet systems require high determinism and reliability. In many factory automation applications, Ethernet has replaced traditional serial "fieldbus" connections due to its higher bandwidth and ability to link to enterprise networks; however, Ethernet itself does not possess the deterministic response of fieldbus systems.
According to HMS's 2017 Industrial Network Market Share Report, Industrial Ethernet is growing faster than in previous years, with a growth rate of 22%. Industrial Ethernet now accounts for 46% of the global market, compared to 38% last year. In specific communication areas, EtherNet/IP and PROFINET have the largest market share. PROFINET's main market is in Central Europe, while EtherNet/IP dominates in North America, followed by EtherCAT, Modbus-TCP, and EthernetPOWERLINK.
The dilemma caused by the coexistence of numerous Ethernet protocols
Manufacturers expect to automate more and more processes across systems, thus requiring consideration of IT systems' need for open data access and the real-time requirements of industrial control systems. Industrial Ethernet systems demand high determinism and reliability. In many factory automation applications, Ethernet has replaced traditional serial "fieldbus" connections due to its higher bandwidth and ability to link to enterprise networks; however, Ethernet itself lacks the deterministic response of fieldbus systems.
To overcome this limitation, major industrial OEMs developed their own Ethernet protocols, which have since become widely used open standards: PROFINET, Ethernet/IP, EtherCAT, ModbusTCP, and several others. Some of these protocols are fully compatible with standard TCP/IP Ethernet networks, while others have modified the data link, network, and/or transport layers (layers 2-4 in the OSI model) to achieve deterministic performance.
Unfortunately, product manufacturers have not yet reached a consensus on a universal industrial Ethernet standard; instead, the field is fragmented, with over 30 different standards deployed in factories. While these protocols can coexist with standard Ethernet, they cannot interoperate with each other in a definitive way. Many leading manufacturers have defined a specific industrial Ethernet standard to meet their needs, often derived from one of their existing serial-based fieldbuses.
Most industrial Ethernet standards require a separate device solution. Figure 1 illustrates one such solution, which includes a microcontroller unit or microprocessor unit and a separate industrial Ethernet device, a media access controller (MAC). This MAC supports real-time Ethernet frame processing, technically known as "instantaneous" or "pass-through" frame processing. Therefore, most industrial Ethernet standards require the application of dedicated integrated circuits or FPGAs to handle real-time Ethernet frame processing.
Make dual Ethernet ports a standard feature in industrial devices.
Industrial networks have unique requirements, such as reliable data transmission and time synchronization. These requirements necessitate different network protocols for different applications, presenting the challenge of overcoming multiple protocol barriers. Analog Devices' fido5000REM switching chips (available in fido5100 and fido5200 models) attempt to address the challenges of various Ethernet protocols as a product solution. The fido5100 supports various major industrial Ethernet protocols except EtherCAT, while the fido5200 supports various major industrial Ethernet protocols including EtherCAT.
The fido5200 supports various major industrial Ethernet protocols, including EtherCAT.
Analog Devices' fido5000 is a real-time Ethernet, multi-protocol (REM) switch chip with two Ethernet ports. This product's introduction makes two ports standard in today's industrial devices, and future Industry 4.0 applications must support various common network topologies, such as linear, ring, and star topologies. Furthermore, it can connect to any host processor, allowing developers to use their own processors and their preferred development environments. The following diagram illustrates all these possibilities and features of the fido5000.
These features of the fido5000 overcome the challenges of Ethernet multiprotocol.
The REM chip and processor communicate via a memory bus to achieve high-performance, low-latency/low-jitter industrial Ethernet. The memory bus also provides a master interface using PriorityChannel™ technology. Analog Devices (ADI) developed this filtering technology through a hardware-software co-design. It ensures that critical data from Ethernet is processed promptly, unaffected by protocol and network utilization, thus avoiding interference from non-time-critical data traffic. This means that data from the real-time channel is processed before ordinary network data. The diagram below illustrates PriorityChannel technology, showing four queues that can be fine-tuned when processing real-time data.
The concept of ADIPriorityChannel technology
Supports timer control and time-sensitive networks, providing backup for Industry 4.0 functions.
In addition to its switching capabilities, the Fido 5000 features a powerful timer control unit. This unit is designed to implement synchronization mechanisms for various industrial Ethernet protocols. Through four dedicated outputs or four general-purpose inputs/outputs, it can perform functions such as input capture and output any square wave signal. These ports are all directly in phase with the synchronization time. For example, it can timestamp the arrival of any edge at any of the four inputs with 64-bit resolution. At the outputs, any digital signal pattern can be output in sync with network time. This means that user applications can be synchronized with network time, with cycle times as low as less than 31.25 seconds.
But the Fido5000's capabilities extend beyond this; this chip is already prepared for the upcoming Industry 4.0! The Fido5000 supports time-sensitive networking. Future industrial Ethernet applications based on time-sensitive networking will be able to meet the extremely demanding real-time requirements of applications such as motion control or safety.
Time-Sensitive Networking (TSN) is a set of standards defined by the IEEE 802.1 working group. It is compatible with existing standard Ethernet technologies. In fact, TSN defined the first IEEE standard for time-controlled data routing in switched Ethernet networks. Therefore, deterministic real-time communication in the IEEE 802 series of standards can be achieved through a common time base and schedule generated for message paths across several network components.
In addition to the single-chip Fido5000, ADI also offers the RapID platform, a complete board-level solution based on the Fido5000. The RapID platform implements all common industrial Ethernet protocols and can be easily integrated into non-Ethernet field devices. This enables field devices to meet the requirements of Industry 4.0 applications. The implementations of common industrial Ethernet protocols are pre-certified. Another interesting feature of the RapID platform is its dynamically integrated web server. This feature allows users to easily read and modify network parameters, input, and output data.
The fido5000REM switch chip and RapID platform provide a good foundation for time-critical applications based on current industrial Ethernet standards and future time-sensitive network standards.
The Fido5000-based RapID platform can be used in the evaluation kit.
The fido5000REM switch chip and RapID platform provide the optimal prerequisites for time-critical applications based on current industrial Ethernet standards and future TSN standards.
