Application Environment of Yaskawa Frequency Converter Connected to Siemens Profibus-DP Network As is well known, Siemens S7 series PLCs are currently widely used in China, while Yaskawa VSG7 series frequency converters are known for their high cost-performance ratio. A reasonable combination of these two in a drive control system is undoubtedly a good choice. In the control system of a large round billet continuous casting machine, the Yaskawa VSG7 frequency converter used for speed regulation of the crystallizer vibration and straightening machine drive is connected to a Profibus-DP network with a Siemens S7-400 PLC (CPU 414-2DP) as the master station. Through Profibus-DP, the master station can monitor the operating status of the frequency converter and set and change its internal parameters. From the operational experience, the results are excellent. In the months since its commissioning, there have been no instances of network data communication being disrupted or interrupted due to interference, nor have there been any faults such as incorrect transmission direction and speed commands or command delays. Besides correct settings and programming, this is also related to the installation of an independent and reliable dedicated grounding system. Generally, Profibus from various manufacturers should comply with the European EN50170 fieldbus standard, while Profibus-DP is a protocol specification (IEC958-2) suitable for distributed I/O. However, in practice, products from different companies differ in their specific applications. Like inverters from other manufacturers, Yaskawa inverters, even when configured with a Profibus-DP interface, may not be directly connected to a Siemens Profibus-DP network. A dedicated interface card and corresponding driver software may be required. The S1-P1 interface card for Profibus-DP network communication in the Yaskawa VsG7 inverter is Yaskawa's second-generation product; the S1-P1 card was released several years ago. Reportedly, several integrators have connected inverters configured with the aforementioned communication card to the Profibus-DP networks of GEFanuc and Siemens, but the results have been less than ideal. [b][align=center]For more details, please click: Data Communication between Yaskawa Inverters and Siemens PLCs[/align][/b]