How to Choose the Right EtherCAT Products - Interoperability Is Key

JZGKCHINA

Industrial Control Technology Sharing Platform

EtherCAT offers higher transmission efficiency and flexibility. After over a decade of development, EtherCAT technology has become one of the mainstream real-time Ethernet fieldbus technologies worldwide. At the same time, EtherCAT technology is fully open. Therefore, more and more devices, both domestically and internationally, are adopting EtherCAT as their bus interface.

In the domestic automation market, as the complexity of machines continues to increase and performance improves, the scale of systems gradually expands. Consequently, in an increasing number of applications, PC-based control technology and EtherCAT bus control architecture have gradually become the top choice for system integration.

For EtherCAT devices, interoperability is crucial and truly effective. Thanks to the classification of EtherCAT master functions and the consistency certification mechanism for slaves, you can easily choose the right EtherCAT device.

The master must support the functions required by the slaves

EtherCAT supports various application layer communication protocols (device profiles) to better meet application needs. When vendors implement EtherCAT devices, they can choose to implement different device profiles. We categorize EtherCAT master devices into Class A and Class B. Different categories of devices indicate different implementation levels of EtherCAT’s application layer protocol (as shown in Figure 1: Figure 1 displays the differences (partial) between Class A and Class B masters). Therefore, when selecting your master, in addition to performance requirements for control tasks, you must consider whether the master can support all slave requirements for device profiles.

For example, some servo drives utilize “Ethernet over EtherCAT” (EoE) to achieve file transfer or configuration functions, which requires the connected master to also have EoE functionality, while simple EtherCAT masters (Class B masters) do not implement EoE, so they cannot be connected.

Figure 1

Consistency requirements for slaves

Consistency is vital for an open technology, and device suppliers must ensure product consistency to be responsible for the final application. According to the ETG’s Vendor ID Policy, all EtherCAT devices must guarantee consistency. Therefore, during system integration, you need to confirm whether EtherCAT slave devices meet consistency requirements. So how can you confirm that the slave devices you purchased meet the consistency requirements? Mainly through the following two methods:

A. Request the device supplier to provide an officially issued consistency test certificate

If they can provide an ETG officially issued consistency test certificate, it indicates that the product has passed authoritative certification, and the product is marked with the “EtherCAT conformance tested” logo. Device suppliers can go to ETG-authorized EtherCAT Test Centers (ETC) for testing and certification, and after passing the tests, receive a certificate issued by ETG headquarters (an example of the official certificate is shown in Figure 2). EtherCAT consistency testing is conducted according to the ETG standard document “ETG. 7000-2 Conformance Test Record”. The testing content includes not only items tested automatically by the consistency testing tool but also manual tests such as ESI checks, slave status indication tests, device identifier display tests, distributed clock tests, miscellaneous, semiconductor device profile tests, device identifier tests, interoperability tests, and more.

Figure 2 Example of a certificate passed by the ETC consistency test

This method of obtaining a consistency test certificate through official certification is very efficient. Device suppliers can present it directly to system integrators/machine manufacturers to prove that the device has good EtherCAT consistency.

It should be noted that the consistency test certificate corresponds to each version number of the device. When the device is updated, new testing is required to ensure that the updated device maintains consistency. Therefore, please pay attention to whether the product number, serial number indicated on the certificate matches the device being used.

Furthermore, ETG-authorized testing centers have an interconnected testing environment that includes products from multiple device suppliers, allowing for better testing of whether the device can work with other devices. The EtherCAT experts at the authorized testing centers are more professional, and the testing results are more authoritative. ETG encourages device suppliers to test at ETG-authorized testing centers.

B. Request the device supplier to provide self-completed test results

Besides undergoing official testing at a consistency testing center, device suppliers can verify their product’s consistency by purchasing consistency testing tools (CTT) and testing it themselves. The laboratory test results clearly show the items that passed and those that did not, as shown in Figure 3.

Figure 3 CTT self-consistency test results

In addition to testing with CTT software, suppliers also need to test other items specified in the ETG standard document “ETG.7000-2 Conformance Test Record” and maintain test records.

All the above considerations should be taken into account from the beginning of the system design. Besides the specific considerations of master functions and slave consistency, the design of machines and cabinets, wiring, and other electrical safety features should comply with GB/T 5226. Compliant designs will reduce unnecessary debugging, maintenance work, and engineering volume during subsequent installation, commissioning, and use, as well as associated hidden costs.

For any system integration, it is clear that choosing products from the same brand for integration poses the lowest risk and higher reliability, as at least the manufacturer of that brand will be responsible for all systems that encounter issues.

However, sometimes due to cost requirements or incomplete product lines offered by a certain brand, it is necessary to procure products from different brands for system integration, in which case the risk will be borne by the system integrator or machine manufacturer. For Ethernet fieldbuses, because EtherCAT has high performance and flexibility advantages, along with complete openness, more device manufacturers support it.

Therefore, when different brand products are integrated into the same EtherCAT system and communication failures occur, system integrators or machine manufacturers should follow the two steps mentioned above for troubleshooting: first confirm the master functions and slave consistency issues, and then proceed to other checks.

Featured Articles

How to Choose the Right EtherCAT Products - Interoperability Is Key

1.Smart200&V90 Servo System:15 lessons updated

2.B&R Live Courses: 30 lessons updated

3.PKS Quick Start: Beginner & Intermediate – Complete

4.Classic Open Courses for Industrial Control:35 lessons updated

5.New Product Recommendations: 10 lessons updated

How to Choose the Right EtherCAT Products – Interoperability Is Key

Leave a Comment Cancel reply

Related posts

Leave a Comment Cancel reply